0
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1 /*
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2 * Copyright 1999-2007 Sun Microsystems, Inc. All Rights Reserved.
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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4 *
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5 * This code is free software; you can redistribute it and/or modify it
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6 * under the terms of the GNU General Public License version 2 only, as
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7 * published by the Free Software Foundation.
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8 *
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9 * This code is distributed in the hope that it will be useful, but WITHOUT
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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12 * version 2 for more details (a copy is included in the LICENSE file that
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13 * accompanied this code).
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14 *
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15 * You should have received a copy of the GNU General Public License version
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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18 *
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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20 * CA 95054 USA or visit www.sun.com if you need additional information or
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21 * have any questions.
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22 *
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23 */
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24
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25 // do not include precompiled header file
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26 # include "incls/_os_linux.cpp.incl"
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27
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28 // put OS-includes here
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29 # include <sys/types.h>
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30 # include <sys/mman.h>
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31 # include <pthread.h>
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32 # include <signal.h>
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33 # include <errno.h>
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34 # include <dlfcn.h>
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35 # include <stdio.h>
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36 # include <unistd.h>
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37 # include <sys/resource.h>
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38 # include <pthread.h>
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39 # include <sys/stat.h>
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40 # include <sys/time.h>
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41 # include <sys/times.h>
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42 # include <sys/utsname.h>
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43 # include <sys/socket.h>
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44 # include <sys/wait.h>
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45 # include <pwd.h>
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46 # include <poll.h>
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47 # include <semaphore.h>
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48 # include <fcntl.h>
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49 # include <string.h>
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50 # include <syscall.h>
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51 # include <sys/sysinfo.h>
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52 # include <gnu/libc-version.h>
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53 # include <sys/ipc.h>
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54 # include <sys/shm.h>
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55 # include <link.h>
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56
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57 #define MAX_PATH (2 * K)
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58
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59 // for timer info max values which include all bits
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60 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
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61 #define SEC_IN_NANOSECS 1000000000LL
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62
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63 ////////////////////////////////////////////////////////////////////////////////
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64 // global variables
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65 julong os::Linux::_physical_memory = 0;
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66
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67 address os::Linux::_initial_thread_stack_bottom = NULL;
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68 uintptr_t os::Linux::_initial_thread_stack_size = 0;
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69
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70 int (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL;
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71 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL;
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72 Mutex* os::Linux::_createThread_lock = NULL;
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73 pthread_t os::Linux::_main_thread;
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74 int os::Linux::_page_size = -1;
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75 bool os::Linux::_is_floating_stack = false;
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76 bool os::Linux::_is_NPTL = false;
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77 bool os::Linux::_supports_fast_thread_cpu_time = false;
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78 char * os::Linux::_glibc_version = NULL;
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79 char * os::Linux::_libpthread_version = NULL;
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80
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81 static jlong initial_time_count=0;
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82
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83 static int clock_tics_per_sec = 100;
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84
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85 // For diagnostics to print a message once. see run_periodic_checks
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86 static sigset_t check_signal_done;
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87 static bool check_signals = true;;
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88
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89 static pid_t _initial_pid = 0;
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90
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91 /* Signal number used to suspend/resume a thread */
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92
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93 /* do not use any signal number less than SIGSEGV, see 4355769 */
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94 static int SR_signum = SIGUSR2;
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95 sigset_t SR_sigset;
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96
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97 ////////////////////////////////////////////////////////////////////////////////
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98 // utility functions
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99
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100 static int SR_initialize();
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101 static int SR_finalize();
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102
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103 julong os::available_memory() {
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104 return Linux::available_memory();
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105 }
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106
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107 julong os::Linux::available_memory() {
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108 // values in struct sysinfo are "unsigned long"
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109 struct sysinfo si;
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110 sysinfo(&si);
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111
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112 return (julong)si.freeram * si.mem_unit;
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113 }
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114
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115 julong os::physical_memory() {
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116 return Linux::physical_memory();
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117 }
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118
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119 ////////////////////////////////////////////////////////////////////////////////
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120 // environment support
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121
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122 bool os::getenv(const char* name, char* buf, int len) {
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123 const char* val = ::getenv(name);
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124 if (val != NULL && strlen(val) < (size_t)len) {
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125 strcpy(buf, val);
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126 return true;
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127 }
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128 if (len > 0) buf[0] = 0; // return a null string
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129 return false;
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130 }
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131
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132
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133 // Return true if user is running as root.
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134
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135 bool os::have_special_privileges() {
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136 static bool init = false;
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137 static bool privileges = false;
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138 if (!init) {
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139 privileges = (getuid() != geteuid()) || (getgid() != getegid());
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140 init = true;
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141 }
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142 return privileges;
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143 }
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144
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145
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146 #ifndef SYS_gettid
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147 // i386: 224, ia64: 1105, amd64: 186, sparc 143
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148 #ifdef __ia64__
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149 #define SYS_gettid 1105
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150 #elif __i386__
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151 #define SYS_gettid 224
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152 #elif __amd64__
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153 #define SYS_gettid 186
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154 #elif __sparc__
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155 #define SYS_gettid 143
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156 #else
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157 #error define gettid for the arch
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158 #endif
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159 #endif
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160
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161 // Cpu architecture string
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162 #if defined(IA64)
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163 static char cpu_arch[] = "ia64";
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164 #elif defined(IA32)
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165 static char cpu_arch[] = "i386";
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166 #elif defined(AMD64)
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167 static char cpu_arch[] = "amd64";
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168 #elif defined(SPARC)
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169 # ifdef _LP64
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170 static char cpu_arch[] = "sparcv9";
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171 # else
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172 static char cpu_arch[] = "sparc";
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173 # endif
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174 #else
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175 #error Add appropriate cpu_arch setting
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176 #endif
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177
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178
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179 // pid_t gettid()
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180 //
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181 // Returns the kernel thread id of the currently running thread. Kernel
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182 // thread id is used to access /proc.
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183 //
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184 // (Note that getpid() on LinuxThreads returns kernel thread id too; but
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185 // on NPTL, it returns the same pid for all threads, as required by POSIX.)
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186 //
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187 pid_t os::Linux::gettid() {
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188 int rslt = syscall(SYS_gettid);
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189 if (rslt == -1) {
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190 // old kernel, no NPTL support
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191 return getpid();
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192 } else {
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193 return (pid_t)rslt;
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194 }
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195 }
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196
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197 // Most versions of linux have a bug where the number of processors are
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198 // determined by looking at the /proc file system. In a chroot environment,
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199 // the system call returns 1. This causes the VM to act as if it is
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200 // a single processor and elide locking (see is_MP() call).
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201 static bool unsafe_chroot_detected = false;
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202 static char *unstable_chroot_error = "/proc file system not found.\n"
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203 "Java may be unstable running multithreaded in a chroot "
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204 "environment on Linux when /proc filesystem is not mounted.";
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205
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206 void os::Linux::initialize_system_info() {
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207 _processor_count = sysconf(_SC_NPROCESSORS_CONF);
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208 if (_processor_count == 1) {
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209 pid_t pid = os::Linux::gettid();
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210 char fname[32];
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211 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid);
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212 FILE *fp = fopen(fname, "r");
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213 if (fp == NULL) {
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214 unsafe_chroot_detected = true;
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215 } else {
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216 fclose(fp);
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217 }
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218 }
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219 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE);
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220 assert(_processor_count > 0, "linux error");
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221 }
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222
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223 void os::init_system_properties_values() {
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224 // char arch[12];
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225 // sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
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226
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227 // The next steps are taken in the product version:
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228 //
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229 // Obtain the JAVA_HOME value from the location of libjvm[_g].so.
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230 // This library should be located at:
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231 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm[_g].so.
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232 //
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233 // If "/jre/lib/" appears at the right place in the path, then we
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234 // assume libjvm[_g].so is installed in a JDK and we use this path.
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235 //
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236 // Otherwise exit with message: "Could not create the Java virtual machine."
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237 //
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238 // The following extra steps are taken in the debugging version:
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239 //
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240 // If "/jre/lib/" does NOT appear at the right place in the path
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241 // instead of exit check for $JAVA_HOME environment variable.
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242 //
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243 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
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244 // then we append a fake suffix "hotspot/libjvm[_g].so" to this path so
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245 // it looks like libjvm[_g].so is installed there
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246 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm[_g].so.
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247 //
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248 // Otherwise exit.
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249 //
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250 // Important note: if the location of libjvm.so changes this
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251 // code needs to be changed accordingly.
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252
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253 // The next few definitions allow the code to be verbatim:
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254 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n))
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255 #define getenv(n) ::getenv(n)
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256
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257 /*
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258 * See ld(1):
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259 * The linker uses the following search paths to locate required
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260 * shared libraries:
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261 * 1: ...
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262 * ...
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263 * 7: The default directories, normally /lib and /usr/lib.
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264 */
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265 #define DEFAULT_LIBPATH "/lib:/usr/lib"
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266
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267 #define EXTENSIONS_DIR "/lib/ext"
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268 #define ENDORSED_DIR "/lib/endorsed"
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269 #define REG_DIR "/usr/java/packages"
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270
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271 {
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272 /* sysclasspath, java_home, dll_dir */
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273 {
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274 char *home_path;
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275 char *dll_path;
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276 char *pslash;
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277 char buf[MAXPATHLEN];
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278 os::jvm_path(buf, sizeof(buf));
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279
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280 // Found the full path to libjvm.so.
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281 // Now cut the path to <java_home>/jre if we can.
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282 *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */
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283 pslash = strrchr(buf, '/');
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284 if (pslash != NULL)
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285 *pslash = '\0'; /* get rid of /{client|server|hotspot} */
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286 dll_path = malloc(strlen(buf) + 1);
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287 if (dll_path == NULL)
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288 return;
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289 strcpy(dll_path, buf);
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290 Arguments::set_dll_dir(dll_path);
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291
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292 if (pslash != NULL) {
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293 pslash = strrchr(buf, '/');
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294 if (pslash != NULL) {
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295 *pslash = '\0'; /* get rid of /<arch> */
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296 pslash = strrchr(buf, '/');
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297 if (pslash != NULL)
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298 *pslash = '\0'; /* get rid of /lib */
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299 }
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300 }
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301
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302 home_path = malloc(strlen(buf) + 1);
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303 if (home_path == NULL)
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304 return;
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305 strcpy(home_path, buf);
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306 Arguments::set_java_home(home_path);
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307
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308 if (!set_boot_path('/', ':'))
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309 return;
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310 }
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311
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312 /*
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313 * Where to look for native libraries
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314 *
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315 * Note: Due to a legacy implementation, most of the library path
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316 * is set in the launcher. This was to accomodate linking restrictions
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317 * on legacy Linux implementations (which are no longer supported).
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318 * Eventually, all the library path setting will be done here.
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319 *
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320 * However, to prevent the proliferation of improperly built native
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321 * libraries, the new path component /usr/java/packages is added here.
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322 * Eventually, all the library path setting will be done here.
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323 */
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324 {
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325 char *ld_library_path;
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326
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327 /*
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328 * Construct the invariant part of ld_library_path. Note that the
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329 * space for the colon and the trailing null are provided by the
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330 * nulls included by the sizeof operator (so actually we allocate
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331 * a byte more than necessary).
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332 */
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333 ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
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334 strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
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335 sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
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336
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337 /*
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338 * Get the user setting of LD_LIBRARY_PATH, and prepended it. It
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339 * should always exist (until the legacy problem cited above is
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340 * addressed).
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341 */
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342 char *v = getenv("LD_LIBRARY_PATH");
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343 if (v != NULL) {
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344 char *t = ld_library_path;
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345 /* That's +1 for the colon and +1 for the trailing '\0' */
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346 ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
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347 sprintf(ld_library_path, "%s:%s", v, t);
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348 }
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349 Arguments::set_library_path(ld_library_path);
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350 }
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351
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352 /*
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353 * Extensions directories.
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354 *
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355 * Note that the space for the colon and the trailing null are provided
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356 * by the nulls included by the sizeof operator (so actually one byte more
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357 * than necessary is allocated).
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358 */
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359 {
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360 char *buf = malloc(strlen(Arguments::get_java_home()) +
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361 sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
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362 sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
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363 Arguments::get_java_home());
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364 Arguments::set_ext_dirs(buf);
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365 }
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366
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367 /* Endorsed standards default directory. */
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368 {
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369 char * buf;
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370 buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
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371 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
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372 Arguments::set_endorsed_dirs(buf);
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373 }
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374 }
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375
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376 #undef malloc
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377 #undef getenv
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378 #undef EXTENSIONS_DIR
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379 #undef ENDORSED_DIR
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380
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381 // Done
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382 return;
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383 }
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384
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385 ////////////////////////////////////////////////////////////////////////////////
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386 // breakpoint support
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387
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388 void os::breakpoint() {
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389 BREAKPOINT;
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390 }
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391
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392 extern "C" void breakpoint() {
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393 // use debugger to set breakpoint here
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394 }
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395
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396 ////////////////////////////////////////////////////////////////////////////////
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397 // signal support
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398
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399 debug_only(static bool signal_sets_initialized = false);
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400 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
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401
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402 bool os::Linux::is_sig_ignored(int sig) {
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403 struct sigaction oact;
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404 sigaction(sig, (struct sigaction*)NULL, &oact);
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405 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
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406 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
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407 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
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408 return true;
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409 else
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410 return false;
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411 }
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412
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413 void os::Linux::signal_sets_init() {
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414 // Should also have an assertion stating we are still single-threaded.
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415 assert(!signal_sets_initialized, "Already initialized");
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416 // Fill in signals that are necessarily unblocked for all threads in
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417 // the VM. Currently, we unblock the following signals:
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418 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
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419 // by -Xrs (=ReduceSignalUsage));
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420 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
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421 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
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422 // the dispositions or masks wrt these signals.
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423 // Programs embedding the VM that want to use the above signals for their
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424 // own purposes must, at this time, use the "-Xrs" option to prevent
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425 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
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426 // (See bug 4345157, and other related bugs).
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427 // In reality, though, unblocking these signals is really a nop, since
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428 // these signals are not blocked by default.
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429 sigemptyset(&unblocked_sigs);
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430 sigemptyset(&allowdebug_blocked_sigs);
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431 sigaddset(&unblocked_sigs, SIGILL);
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432 sigaddset(&unblocked_sigs, SIGSEGV);
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433 sigaddset(&unblocked_sigs, SIGBUS);
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434 sigaddset(&unblocked_sigs, SIGFPE);
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435 sigaddset(&unblocked_sigs, SR_signum);
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436
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437 if (!ReduceSignalUsage) {
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438 if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
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439 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
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440 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
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441 }
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442 if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
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443 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
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444 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
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445 }
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446 if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
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447 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
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448 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
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449 }
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450 }
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451 // Fill in signals that are blocked by all but the VM thread.
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452 sigemptyset(&vm_sigs);
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453 if (!ReduceSignalUsage)
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454 sigaddset(&vm_sigs, BREAK_SIGNAL);
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455 debug_only(signal_sets_initialized = true);
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456
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457 }
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458
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459 // These are signals that are unblocked while a thread is running Java.
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460 // (For some reason, they get blocked by default.)
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461 sigset_t* os::Linux::unblocked_signals() {
|
|
462 assert(signal_sets_initialized, "Not initialized");
|
|
463 return &unblocked_sigs;
|
|
464 }
|
|
465
|
|
466 // These are the signals that are blocked while a (non-VM) thread is
|
|
467 // running Java. Only the VM thread handles these signals.
|
|
468 sigset_t* os::Linux::vm_signals() {
|
|
469 assert(signal_sets_initialized, "Not initialized");
|
|
470 return &vm_sigs;
|
|
471 }
|
|
472
|
|
473 // These are signals that are blocked during cond_wait to allow debugger in
|
|
474 sigset_t* os::Linux::allowdebug_blocked_signals() {
|
|
475 assert(signal_sets_initialized, "Not initialized");
|
|
476 return &allowdebug_blocked_sigs;
|
|
477 }
|
|
478
|
|
479 void os::Linux::hotspot_sigmask(Thread* thread) {
|
|
480
|
|
481 //Save caller's signal mask before setting VM signal mask
|
|
482 sigset_t caller_sigmask;
|
|
483 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
|
|
484
|
|
485 OSThread* osthread = thread->osthread();
|
|
486 osthread->set_caller_sigmask(caller_sigmask);
|
|
487
|
|
488 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL);
|
|
489
|
|
490 if (!ReduceSignalUsage) {
|
|
491 if (thread->is_VM_thread()) {
|
|
492 // Only the VM thread handles BREAK_SIGNAL ...
|
|
493 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
|
|
494 } else {
|
|
495 // ... all other threads block BREAK_SIGNAL
|
|
496 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
|
|
497 }
|
|
498 }
|
|
499 }
|
|
500
|
|
501 //////////////////////////////////////////////////////////////////////////////
|
|
502 // detecting pthread library
|
|
503
|
|
504 void os::Linux::libpthread_init() {
|
|
505 // Save glibc and pthread version strings. Note that _CS_GNU_LIBC_VERSION
|
|
506 // and _CS_GNU_LIBPTHREAD_VERSION are supported in glibc >= 2.3.2. Use a
|
|
507 // generic name for earlier versions.
|
|
508 // Define macros here so we can build HotSpot on old systems.
|
|
509 # ifndef _CS_GNU_LIBC_VERSION
|
|
510 # define _CS_GNU_LIBC_VERSION 2
|
|
511 # endif
|
|
512 # ifndef _CS_GNU_LIBPTHREAD_VERSION
|
|
513 # define _CS_GNU_LIBPTHREAD_VERSION 3
|
|
514 # endif
|
|
515
|
|
516 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0);
|
|
517 if (n > 0) {
|
|
518 char *str = (char *)malloc(n);
|
|
519 confstr(_CS_GNU_LIBC_VERSION, str, n);
|
|
520 os::Linux::set_glibc_version(str);
|
|
521 } else {
|
|
522 // _CS_GNU_LIBC_VERSION is not supported, try gnu_get_libc_version()
|
|
523 static char _gnu_libc_version[32];
|
|
524 jio_snprintf(_gnu_libc_version, sizeof(_gnu_libc_version),
|
|
525 "glibc %s %s", gnu_get_libc_version(), gnu_get_libc_release());
|
|
526 os::Linux::set_glibc_version(_gnu_libc_version);
|
|
527 }
|
|
528
|
|
529 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0);
|
|
530 if (n > 0) {
|
|
531 char *str = (char *)malloc(n);
|
|
532 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n);
|
|
533
|
|
534 // Vanilla RH-9 (glibc 2.3.2) has a bug that confstr() always tells
|
|
535 // us "NPTL-0.29" even we are running with LinuxThreads. Check if this
|
|
536 // is the case:
|
|
537 if (strcmp(os::Linux::glibc_version(), "glibc 2.3.2") == 0 &&
|
|
538 strstr(str, "NPTL")) {
|
|
539 // LinuxThreads has a hard limit on max number of threads. So
|
|
540 // sysconf(_SC_THREAD_THREADS_MAX) will return a positive value.
|
|
541 // On the other hand, NPTL does not have such a limit, sysconf()
|
|
542 // will return -1 and errno is not changed. Check if it is really
|
|
543 // NPTL:
|
|
544 if (sysconf(_SC_THREAD_THREADS_MAX) > 0) {
|
|
545 free(str);
|
|
546 str = "linuxthreads";
|
|
547 }
|
|
548 }
|
|
549 os::Linux::set_libpthread_version(str);
|
|
550 } else {
|
|
551 // glibc before 2.3.2 only has LinuxThreads.
|
|
552 os::Linux::set_libpthread_version("linuxthreads");
|
|
553 }
|
|
554
|
|
555 if (strstr(libpthread_version(), "NPTL")) {
|
|
556 os::Linux::set_is_NPTL();
|
|
557 } else {
|
|
558 os::Linux::set_is_LinuxThreads();
|
|
559 }
|
|
560
|
|
561 // LinuxThreads have two flavors: floating-stack mode, which allows variable
|
|
562 // stack size; and fixed-stack mode. NPTL is always floating-stack.
|
|
563 if (os::Linux::is_NPTL() || os::Linux::supports_variable_stack_size()) {
|
|
564 os::Linux::set_is_floating_stack();
|
|
565 }
|
|
566 }
|
|
567
|
|
568 /////////////////////////////////////////////////////////////////////////////
|
|
569 // thread stack
|
|
570
|
|
571 // Force Linux kernel to expand current thread stack. If "bottom" is close
|
|
572 // to the stack guard, caller should block all signals.
|
|
573 //
|
|
574 // MAP_GROWSDOWN:
|
|
575 // A special mmap() flag that is used to implement thread stacks. It tells
|
|
576 // kernel that the memory region should extend downwards when needed. This
|
|
577 // allows early versions of LinuxThreads to only mmap the first few pages
|
|
578 // when creating a new thread. Linux kernel will automatically expand thread
|
|
579 // stack as needed (on page faults).
|
|
580 //
|
|
581 // However, because the memory region of a MAP_GROWSDOWN stack can grow on
|
|
582 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN
|
|
583 // region, it's hard to tell if the fault is due to a legitimate stack
|
|
584 // access or because of reading/writing non-exist memory (e.g. buffer
|
|
585 // overrun). As a rule, if the fault happens below current stack pointer,
|
|
586 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the
|
|
587 // application (see Linux kernel fault.c).
|
|
588 //
|
|
589 // This Linux feature can cause SIGSEGV when VM bangs thread stack for
|
|
590 // stack overflow detection.
|
|
591 //
|
|
592 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do
|
|
593 // not use this flag. However, the stack of initial thread is not created
|
|
594 // by pthread, it is still MAP_GROWSDOWN. Also it's possible (though
|
|
595 // unlikely) that user code can create a thread with MAP_GROWSDOWN stack
|
|
596 // and then attach the thread to JVM.
|
|
597 //
|
|
598 // To get around the problem and allow stack banging on Linux, we need to
|
|
599 // manually expand thread stack after receiving the SIGSEGV.
|
|
600 //
|
|
601 // There are two ways to expand thread stack to address "bottom", we used
|
|
602 // both of them in JVM before 1.5:
|
|
603 // 1. adjust stack pointer first so that it is below "bottom", and then
|
|
604 // touch "bottom"
|
|
605 // 2. mmap() the page in question
|
|
606 //
|
|
607 // Now alternate signal stack is gone, it's harder to use 2. For instance,
|
|
608 // if current sp is already near the lower end of page 101, and we need to
|
|
609 // call mmap() to map page 100, it is possible that part of the mmap() frame
|
|
610 // will be placed in page 100. When page 100 is mapped, it is zero-filled.
|
|
611 // That will destroy the mmap() frame and cause VM to crash.
|
|
612 //
|
|
613 // The following code works by adjusting sp first, then accessing the "bottom"
|
|
614 // page to force a page fault. Linux kernel will then automatically expand the
|
|
615 // stack mapping.
|
|
616 //
|
|
617 // _expand_stack_to() assumes its frame size is less than page size, which
|
|
618 // should always be true if the function is not inlined.
|
|
619
|
|
620 #if __GNUC__ < 3 // gcc 2.x does not support noinline attribute
|
|
621 #define NOINLINE
|
|
622 #else
|
|
623 #define NOINLINE __attribute__ ((noinline))
|
|
624 #endif
|
|
625
|
|
626 static void _expand_stack_to(address bottom) NOINLINE;
|
|
627
|
|
628 static void _expand_stack_to(address bottom) {
|
|
629 address sp;
|
|
630 size_t size;
|
|
631 volatile char *p;
|
|
632
|
|
633 // Adjust bottom to point to the largest address within the same page, it
|
|
634 // gives us a one-page buffer if alloca() allocates slightly more memory.
|
|
635 bottom = (address)align_size_down((uintptr_t)bottom, os::Linux::page_size());
|
|
636 bottom += os::Linux::page_size() - 1;
|
|
637
|
|
638 // sp might be slightly above current stack pointer; if that's the case, we
|
|
639 // will alloca() a little more space than necessary, which is OK. Don't use
|
|
640 // os::current_stack_pointer(), as its result can be slightly below current
|
|
641 // stack pointer, causing us to not alloca enough to reach "bottom".
|
|
642 sp = (address)&sp;
|
|
643
|
|
644 if (sp > bottom) {
|
|
645 size = sp - bottom;
|
|
646 p = (volatile char *)alloca(size);
|
|
647 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?");
|
|
648 p[0] = '\0';
|
|
649 }
|
|
650 }
|
|
651
|
|
652 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) {
|
|
653 assert(t!=NULL, "just checking");
|
|
654 assert(t->osthread()->expanding_stack(), "expand should be set");
|
|
655 assert(t->stack_base() != NULL, "stack_base was not initialized");
|
|
656
|
|
657 if (addr < t->stack_base() && addr >= t->stack_yellow_zone_base()) {
|
|
658 sigset_t mask_all, old_sigset;
|
|
659 sigfillset(&mask_all);
|
|
660 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset);
|
|
661 _expand_stack_to(addr);
|
|
662 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL);
|
|
663 return true;
|
|
664 }
|
|
665 return false;
|
|
666 }
|
|
667
|
|
668 //////////////////////////////////////////////////////////////////////////////
|
|
669 // create new thread
|
|
670
|
|
671 static address highest_vm_reserved_address();
|
|
672
|
|
673 // check if it's safe to start a new thread
|
|
674 static bool _thread_safety_check(Thread* thread) {
|
|
675 if (os::Linux::is_LinuxThreads() && !os::Linux::is_floating_stack()) {
|
|
676 // Fixed stack LinuxThreads (SuSE Linux/x86, and some versions of Redhat)
|
|
677 // Heap is mmap'ed at lower end of memory space. Thread stacks are
|
|
678 // allocated (MAP_FIXED) from high address space. Every thread stack
|
|
679 // occupies a fixed size slot (usually 2Mbytes, but user can change
|
|
680 // it to other values if they rebuild LinuxThreads).
|
|
681 //
|
|
682 // Problem with MAP_FIXED is that mmap() can still succeed even part of
|
|
683 // the memory region has already been mmap'ed. That means if we have too
|
|
684 // many threads and/or very large heap, eventually thread stack will
|
|
685 // collide with heap.
|
|
686 //
|
|
687 // Here we try to prevent heap/stack collision by comparing current
|
|
688 // stack bottom with the highest address that has been mmap'ed by JVM
|
|
689 // plus a safety margin for memory maps created by native code.
|
|
690 //
|
|
691 // This feature can be disabled by setting ThreadSafetyMargin to 0
|
|
692 //
|
|
693 if (ThreadSafetyMargin > 0) {
|
|
694 address stack_bottom = os::current_stack_base() - os::current_stack_size();
|
|
695
|
|
696 // not safe if our stack extends below the safety margin
|
|
697 return stack_bottom - ThreadSafetyMargin >= highest_vm_reserved_address();
|
|
698 } else {
|
|
699 return true;
|
|
700 }
|
|
701 } else {
|
|
702 // Floating stack LinuxThreads or NPTL:
|
|
703 // Unlike fixed stack LinuxThreads, thread stacks are not MAP_FIXED. When
|
|
704 // there's not enough space left, pthread_create() will fail. If we come
|
|
705 // here, that means enough space has been reserved for stack.
|
|
706 return true;
|
|
707 }
|
|
708 }
|
|
709
|
|
710 // Thread start routine for all newly created threads
|
|
711 static void *java_start(Thread *thread) {
|
|
712 // Try to randomize the cache line index of hot stack frames.
|
|
713 // This helps when threads of the same stack traces evict each other's
|
|
714 // cache lines. The threads can be either from the same JVM instance, or
|
|
715 // from different JVM instances. The benefit is especially true for
|
|
716 // processors with hyperthreading technology.
|
|
717 static int counter = 0;
|
|
718 int pid = os::current_process_id();
|
|
719 alloca(((pid ^ counter++) & 7) * 128);
|
|
720
|
|
721 ThreadLocalStorage::set_thread(thread);
|
|
722
|
|
723 OSThread* osthread = thread->osthread();
|
|
724 Monitor* sync = osthread->startThread_lock();
|
|
725
|
|
726 // non floating stack LinuxThreads needs extra check, see above
|
|
727 if (!_thread_safety_check(thread)) {
|
|
728 // notify parent thread
|
|
729 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
|
|
730 osthread->set_state(ZOMBIE);
|
|
731 sync->notify_all();
|
|
732 return NULL;
|
|
733 }
|
|
734
|
|
735 // thread_id is kernel thread id (similar to Solaris LWP id)
|
|
736 osthread->set_thread_id(os::Linux::gettid());
|
|
737
|
|
738 if (UseNUMA) {
|
|
739 int lgrp_id = os::numa_get_group_id();
|
|
740 if (lgrp_id != -1) {
|
|
741 thread->set_lgrp_id(lgrp_id);
|
|
742 }
|
|
743 }
|
|
744 // initialize signal mask for this thread
|
|
745 os::Linux::hotspot_sigmask(thread);
|
|
746
|
|
747 // initialize floating point control register
|
|
748 os::Linux::init_thread_fpu_state();
|
|
749
|
|
750 // handshaking with parent thread
|
|
751 {
|
|
752 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
|
|
753
|
|
754 // notify parent thread
|
|
755 osthread->set_state(INITIALIZED);
|
|
756 sync->notify_all();
|
|
757
|
|
758 // wait until os::start_thread()
|
|
759 while (osthread->get_state() == INITIALIZED) {
|
|
760 sync->wait(Mutex::_no_safepoint_check_flag);
|
|
761 }
|
|
762 }
|
|
763
|
|
764 // call one more level start routine
|
|
765 thread->run();
|
|
766
|
|
767 return 0;
|
|
768 }
|
|
769
|
|
770 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
|
|
771 assert(thread->osthread() == NULL, "caller responsible");
|
|
772
|
|
773 // Allocate the OSThread object
|
|
774 OSThread* osthread = new OSThread(NULL, NULL);
|
|
775 if (osthread == NULL) {
|
|
776 return false;
|
|
777 }
|
|
778
|
|
779 // set the correct thread state
|
|
780 osthread->set_thread_type(thr_type);
|
|
781
|
|
782 // Initial state is ALLOCATED but not INITIALIZED
|
|
783 osthread->set_state(ALLOCATED);
|
|
784
|
|
785 thread->set_osthread(osthread);
|
|
786
|
|
787 // init thread attributes
|
|
788 pthread_attr_t attr;
|
|
789 pthread_attr_init(&attr);
|
|
790 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
|
|
791
|
|
792 // stack size
|
|
793 if (os::Linux::supports_variable_stack_size()) {
|
|
794 // calculate stack size if it's not specified by caller
|
|
795 if (stack_size == 0) {
|
|
796 stack_size = os::Linux::default_stack_size(thr_type);
|
|
797
|
|
798 switch (thr_type) {
|
|
799 case os::java_thread:
|
|
800 // Java threads use ThreadStackSize which default value can be changed with the flag -Xss
|
|
801 if (JavaThread::stack_size_at_create() > 0) stack_size = JavaThread::stack_size_at_create();
|
|
802 break;
|
|
803 case os::compiler_thread:
|
|
804 if (CompilerThreadStackSize > 0) {
|
|
805 stack_size = (size_t)(CompilerThreadStackSize * K);
|
|
806 break;
|
|
807 } // else fall through:
|
|
808 // use VMThreadStackSize if CompilerThreadStackSize is not defined
|
|
809 case os::vm_thread:
|
|
810 case os::pgc_thread:
|
|
811 case os::cgc_thread:
|
|
812 case os::watcher_thread:
|
|
813 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
|
|
814 break;
|
|
815 }
|
|
816 }
|
|
817
|
|
818 stack_size = MAX2(stack_size, os::Linux::min_stack_allowed);
|
|
819 pthread_attr_setstacksize(&attr, stack_size);
|
|
820 } else {
|
|
821 // let pthread_create() pick the default value.
|
|
822 }
|
|
823
|
|
824 // glibc guard page
|
|
825 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type));
|
|
826
|
|
827 ThreadState state;
|
|
828
|
|
829 {
|
|
830 // Serialize thread creation if we are running with fixed stack LinuxThreads
|
|
831 bool lock = os::Linux::is_LinuxThreads() && !os::Linux::is_floating_stack();
|
|
832 if (lock) {
|
|
833 os::Linux::createThread_lock()->lock_without_safepoint_check();
|
|
834 }
|
|
835
|
|
836 pthread_t tid;
|
|
837 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
|
|
838
|
|
839 pthread_attr_destroy(&attr);
|
|
840
|
|
841 if (ret != 0) {
|
|
842 if (PrintMiscellaneous && (Verbose || WizardMode)) {
|
|
843 perror("pthread_create()");
|
|
844 }
|
|
845 // Need to clean up stuff we've allocated so far
|
|
846 thread->set_osthread(NULL);
|
|
847 delete osthread;
|
|
848 if (lock) os::Linux::createThread_lock()->unlock();
|
|
849 return false;
|
|
850 }
|
|
851
|
|
852 // Store pthread info into the OSThread
|
|
853 osthread->set_pthread_id(tid);
|
|
854
|
|
855 // Wait until child thread is either initialized or aborted
|
|
856 {
|
|
857 Monitor* sync_with_child = osthread->startThread_lock();
|
|
858 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
|
|
859 while ((state = osthread->get_state()) == ALLOCATED) {
|
|
860 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
|
|
861 }
|
|
862 }
|
|
863
|
|
864 if (lock) {
|
|
865 os::Linux::createThread_lock()->unlock();
|
|
866 }
|
|
867 }
|
|
868
|
|
869 // Aborted due to thread limit being reached
|
|
870 if (state == ZOMBIE) {
|
|
871 thread->set_osthread(NULL);
|
|
872 delete osthread;
|
|
873 return false;
|
|
874 }
|
|
875
|
|
876 // The thread is returned suspended (in state INITIALIZED),
|
|
877 // and is started higher up in the call chain
|
|
878 assert(state == INITIALIZED, "race condition");
|
|
879 return true;
|
|
880 }
|
|
881
|
|
882 /////////////////////////////////////////////////////////////////////////////
|
|
883 // attach existing thread
|
|
884
|
|
885 // bootstrap the main thread
|
|
886 bool os::create_main_thread(JavaThread* thread) {
|
|
887 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread");
|
|
888 return create_attached_thread(thread);
|
|
889 }
|
|
890
|
|
891 bool os::create_attached_thread(JavaThread* thread) {
|
|
892 #ifdef ASSERT
|
|
893 thread->verify_not_published();
|
|
894 #endif
|
|
895
|
|
896 // Allocate the OSThread object
|
|
897 OSThread* osthread = new OSThread(NULL, NULL);
|
|
898
|
|
899 if (osthread == NULL) {
|
|
900 return false;
|
|
901 }
|
|
902
|
|
903 // Store pthread info into the OSThread
|
|
904 osthread->set_thread_id(os::Linux::gettid());
|
|
905 osthread->set_pthread_id(::pthread_self());
|
|
906
|
|
907 // initialize floating point control register
|
|
908 os::Linux::init_thread_fpu_state();
|
|
909
|
|
910 // Initial thread state is RUNNABLE
|
|
911 osthread->set_state(RUNNABLE);
|
|
912
|
|
913 thread->set_osthread(osthread);
|
|
914
|
|
915 if (UseNUMA) {
|
|
916 int lgrp_id = os::numa_get_group_id();
|
|
917 if (lgrp_id != -1) {
|
|
918 thread->set_lgrp_id(lgrp_id);
|
|
919 }
|
|
920 }
|
|
921
|
|
922 if (os::Linux::is_initial_thread()) {
|
|
923 // If current thread is initial thread, its stack is mapped on demand,
|
|
924 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map
|
|
925 // the entire stack region to avoid SEGV in stack banging.
|
|
926 // It is also useful to get around the heap-stack-gap problem on SuSE
|
|
927 // kernel (see 4821821 for details). We first expand stack to the top
|
|
928 // of yellow zone, then enable stack yellow zone (order is significant,
|
|
929 // enabling yellow zone first will crash JVM on SuSE Linux), so there
|
|
930 // is no gap between the last two virtual memory regions.
|
|
931
|
|
932 JavaThread *jt = (JavaThread *)thread;
|
|
933 address addr = jt->stack_yellow_zone_base();
|
|
934 assert(addr != NULL, "initialization problem?");
|
|
935 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled");
|
|
936
|
|
937 osthread->set_expanding_stack();
|
|
938 os::Linux::manually_expand_stack(jt, addr);
|
|
939 osthread->clear_expanding_stack();
|
|
940 }
|
|
941
|
|
942 // initialize signal mask for this thread
|
|
943 // and save the caller's signal mask
|
|
944 os::Linux::hotspot_sigmask(thread);
|
|
945
|
|
946 return true;
|
|
947 }
|
|
948
|
|
949 void os::pd_start_thread(Thread* thread) {
|
|
950 OSThread * osthread = thread->osthread();
|
|
951 assert(osthread->get_state() != INITIALIZED, "just checking");
|
|
952 Monitor* sync_with_child = osthread->startThread_lock();
|
|
953 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
|
|
954 sync_with_child->notify();
|
|
955 }
|
|
956
|
|
957 // Free Linux resources related to the OSThread
|
|
958 void os::free_thread(OSThread* osthread) {
|
|
959 assert(osthread != NULL, "osthread not set");
|
|
960
|
|
961 if (Thread::current()->osthread() == osthread) {
|
|
962 // Restore caller's signal mask
|
|
963 sigset_t sigmask = osthread->caller_sigmask();
|
|
964 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
|
|
965 }
|
|
966
|
|
967 delete osthread;
|
|
968 }
|
|
969
|
|
970 //////////////////////////////////////////////////////////////////////////////
|
|
971 // thread local storage
|
|
972
|
|
973 int os::allocate_thread_local_storage() {
|
|
974 pthread_key_t key;
|
|
975 int rslt = pthread_key_create(&key, NULL);
|
|
976 assert(rslt == 0, "cannot allocate thread local storage");
|
|
977 return (int)key;
|
|
978 }
|
|
979
|
|
980 // Note: This is currently not used by VM, as we don't destroy TLS key
|
|
981 // on VM exit.
|
|
982 void os::free_thread_local_storage(int index) {
|
|
983 int rslt = pthread_key_delete((pthread_key_t)index);
|
|
984 assert(rslt == 0, "invalid index");
|
|
985 }
|
|
986
|
|
987 void os::thread_local_storage_at_put(int index, void* value) {
|
|
988 int rslt = pthread_setspecific((pthread_key_t)index, value);
|
|
989 assert(rslt == 0, "pthread_setspecific failed");
|
|
990 }
|
|
991
|
|
992 extern "C" Thread* get_thread() {
|
|
993 return ThreadLocalStorage::thread();
|
|
994 }
|
|
995
|
|
996 //////////////////////////////////////////////////////////////////////////////
|
|
997 // initial thread
|
|
998
|
|
999 // Check if current thread is the initial thread, similar to Solaris thr_main.
|
|
1000 bool os::Linux::is_initial_thread(void) {
|
|
1001 char dummy;
|
|
1002 // If called before init complete, thread stack bottom will be null.
|
|
1003 // Can be called if fatal error occurs before initialization.
|
|
1004 if (initial_thread_stack_bottom() == NULL) return false;
|
|
1005 assert(initial_thread_stack_bottom() != NULL &&
|
|
1006 initial_thread_stack_size() != 0,
|
|
1007 "os::init did not locate initial thread's stack region");
|
|
1008 if ((address)&dummy >= initial_thread_stack_bottom() &&
|
|
1009 (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size())
|
|
1010 return true;
|
|
1011 else return false;
|
|
1012 }
|
|
1013
|
|
1014 // Find the virtual memory area that contains addr
|
|
1015 static bool find_vma(address addr, address* vma_low, address* vma_high) {
|
|
1016 FILE *fp = fopen("/proc/self/maps", "r");
|
|
1017 if (fp) {
|
|
1018 address low, high;
|
|
1019 while (!feof(fp)) {
|
|
1020 if (fscanf(fp, "%p-%p", &low, &high) == 2) {
|
|
1021 if (low <= addr && addr < high) {
|
|
1022 if (vma_low) *vma_low = low;
|
|
1023 if (vma_high) *vma_high = high;
|
|
1024 fclose (fp);
|
|
1025 return true;
|
|
1026 }
|
|
1027 }
|
|
1028 for (;;) {
|
|
1029 int ch = fgetc(fp);
|
|
1030 if (ch == EOF || ch == (int)'\n') break;
|
|
1031 }
|
|
1032 }
|
|
1033 fclose(fp);
|
|
1034 }
|
|
1035 return false;
|
|
1036 }
|
|
1037
|
|
1038 // Locate initial thread stack. This special handling of initial thread stack
|
|
1039 // is needed because pthread_getattr_np() on most (all?) Linux distros returns
|
|
1040 // bogus value for initial thread.
|
|
1041 void os::Linux::capture_initial_stack(size_t max_size) {
|
|
1042 // stack size is the easy part, get it from RLIMIT_STACK
|
|
1043 size_t stack_size;
|
|
1044 struct rlimit rlim;
|
|
1045 getrlimit(RLIMIT_STACK, &rlim);
|
|
1046 stack_size = rlim.rlim_cur;
|
|
1047
|
|
1048 // 6308388: a bug in ld.so will relocate its own .data section to the
|
|
1049 // lower end of primordial stack; reduce ulimit -s value a little bit
|
|
1050 // so we won't install guard page on ld.so's data section.
|
|
1051 stack_size -= 2 * page_size();
|
|
1052
|
|
1053 // 4441425: avoid crash with "unlimited" stack size on SuSE 7.1 or Redhat
|
|
1054 // 7.1, in both cases we will get 2G in return value.
|
|
1055 // 4466587: glibc 2.2.x compiled w/o "--enable-kernel=2.4.0" (RH 7.0,
|
|
1056 // SuSE 7.2, Debian) can not handle alternate signal stack correctly
|
|
1057 // for initial thread if its stack size exceeds 6M. Cap it at 2M,
|
|
1058 // in case other parts in glibc still assumes 2M max stack size.
|
|
1059 // FIXME: alt signal stack is gone, maybe we can relax this constraint?
|
|
1060 #ifndef IA64
|
|
1061 if (stack_size > 2 * K * K) stack_size = 2 * K * K;
|
|
1062 #else
|
|
1063 // Problem still exists RH7.2 (IA64 anyway) but 2MB is a little small
|
|
1064 if (stack_size > 4 * K * K) stack_size = 4 * K * K;
|
|
1065 #endif
|
|
1066
|
|
1067 // Try to figure out where the stack base (top) is. This is harder.
|
|
1068 //
|
|
1069 // When an application is started, glibc saves the initial stack pointer in
|
|
1070 // a global variable "__libc_stack_end", which is then used by system
|
|
1071 // libraries. __libc_stack_end should be pretty close to stack top. The
|
|
1072 // variable is available since the very early days. However, because it is
|
|
1073 // a private interface, it could disappear in the future.
|
|
1074 //
|
|
1075 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar
|
|
1076 // to __libc_stack_end, it is very close to stack top, but isn't the real
|
|
1077 // stack top. Note that /proc may not exist if VM is running as a chroot
|
|
1078 // program, so reading /proc/<pid>/stat could fail. Also the contents of
|
|
1079 // /proc/<pid>/stat could change in the future (though unlikely).
|
|
1080 //
|
|
1081 // We try __libc_stack_end first. If that doesn't work, look for
|
|
1082 // /proc/<pid>/stat. If neither of them works, we use current stack pointer
|
|
1083 // as a hint, which should work well in most cases.
|
|
1084
|
|
1085 uintptr_t stack_start;
|
|
1086
|
|
1087 // try __libc_stack_end first
|
|
1088 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end");
|
|
1089 if (p && *p) {
|
|
1090 stack_start = *p;
|
|
1091 } else {
|
|
1092 // see if we can get the start_stack field from /proc/self/stat
|
|
1093 FILE *fp;
|
|
1094 int pid;
|
|
1095 char state;
|
|
1096 int ppid;
|
|
1097 int pgrp;
|
|
1098 int session;
|
|
1099 int nr;
|
|
1100 int tpgrp;
|
|
1101 unsigned long flags;
|
|
1102 unsigned long minflt;
|
|
1103 unsigned long cminflt;
|
|
1104 unsigned long majflt;
|
|
1105 unsigned long cmajflt;
|
|
1106 unsigned long utime;
|
|
1107 unsigned long stime;
|
|
1108 long cutime;
|
|
1109 long cstime;
|
|
1110 long prio;
|
|
1111 long nice;
|
|
1112 long junk;
|
|
1113 long it_real;
|
|
1114 uintptr_t start;
|
|
1115 uintptr_t vsize;
|
|
1116 uintptr_t rss;
|
|
1117 unsigned long rsslim;
|
|
1118 uintptr_t scodes;
|
|
1119 uintptr_t ecode;
|
|
1120 int i;
|
|
1121
|
|
1122 // Figure what the primordial thread stack base is. Code is inspired
|
|
1123 // by email from Hans Boehm. /proc/self/stat begins with current pid,
|
|
1124 // followed by command name surrounded by parentheses, state, etc.
|
|
1125 char stat[2048];
|
|
1126 int statlen;
|
|
1127
|
|
1128 fp = fopen("/proc/self/stat", "r");
|
|
1129 if (fp) {
|
|
1130 statlen = fread(stat, 1, 2047, fp);
|
|
1131 stat[statlen] = '\0';
|
|
1132 fclose(fp);
|
|
1133
|
|
1134 // Skip pid and the command string. Note that we could be dealing with
|
|
1135 // weird command names, e.g. user could decide to rename java launcher
|
|
1136 // to "java 1.4.2 :)", then the stat file would look like
|
|
1137 // 1234 (java 1.4.2 :)) R ... ...
|
|
1138 // We don't really need to know the command string, just find the last
|
|
1139 // occurrence of ")" and then start parsing from there. See bug 4726580.
|
|
1140 char * s = strrchr(stat, ')');
|
|
1141
|
|
1142 i = 0;
|
|
1143 if (s) {
|
|
1144 // Skip blank chars
|
|
1145 do s++; while (isspace(*s));
|
|
1146
|
|
1147 /* 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 */
|
|
1148 /* 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 */
|
|
1149 i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld %lu %lu %ld %lu %lu %lu %lu",
|
|
1150 &state, /* 3 %c */
|
|
1151 &ppid, /* 4 %d */
|
|
1152 &pgrp, /* 5 %d */
|
|
1153 &session, /* 6 %d */
|
|
1154 &nr, /* 7 %d */
|
|
1155 &tpgrp, /* 8 %d */
|
|
1156 &flags, /* 9 %lu */
|
|
1157 &minflt, /* 10 %lu */
|
|
1158 &cminflt, /* 11 %lu */
|
|
1159 &majflt, /* 12 %lu */
|
|
1160 &cmajflt, /* 13 %lu */
|
|
1161 &utime, /* 14 %lu */
|
|
1162 &stime, /* 15 %lu */
|
|
1163 &cutime, /* 16 %ld */
|
|
1164 &cstime, /* 17 %ld */
|
|
1165 &prio, /* 18 %ld */
|
|
1166 &nice, /* 19 %ld */
|
|
1167 &junk, /* 20 %ld */
|
|
1168 &it_real, /* 21 %ld */
|
|
1169 &start, /* 22 %lu */
|
|
1170 &vsize, /* 23 %lu */
|
|
1171 &rss, /* 24 %ld */
|
|
1172 &rsslim, /* 25 %lu */
|
|
1173 &scodes, /* 26 %lu */
|
|
1174 &ecode, /* 27 %lu */
|
|
1175 &stack_start); /* 28 %lu */
|
|
1176 }
|
|
1177
|
|
1178 if (i != 28 - 2) {
|
|
1179 assert(false, "Bad conversion from /proc/self/stat");
|
|
1180 // product mode - assume we are the initial thread, good luck in the
|
|
1181 // embedded case.
|
|
1182 warning("Can't detect initial thread stack location - bad conversion");
|
|
1183 stack_start = (uintptr_t) &rlim;
|
|
1184 }
|
|
1185 } else {
|
|
1186 // For some reason we can't open /proc/self/stat (for example, running on
|
|
1187 // FreeBSD with a Linux emulator, or inside chroot), this should work for
|
|
1188 // most cases, so don't abort:
|
|
1189 warning("Can't detect initial thread stack location - no /proc/self/stat");
|
|
1190 stack_start = (uintptr_t) &rlim;
|
|
1191 }
|
|
1192 }
|
|
1193
|
|
1194 // Now we have a pointer (stack_start) very close to the stack top, the
|
|
1195 // next thing to do is to figure out the exact location of stack top. We
|
|
1196 // can find out the virtual memory area that contains stack_start by
|
|
1197 // reading /proc/self/maps, it should be the last vma in /proc/self/maps,
|
|
1198 // and its upper limit is the real stack top. (again, this would fail if
|
|
1199 // running inside chroot, because /proc may not exist.)
|
|
1200
|
|
1201 uintptr_t stack_top;
|
|
1202 address low, high;
|
|
1203 if (find_vma((address)stack_start, &low, &high)) {
|
|
1204 // success, "high" is the true stack top. (ignore "low", because initial
|
|
1205 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.)
|
|
1206 stack_top = (uintptr_t)high;
|
|
1207 } else {
|
|
1208 // failed, likely because /proc/self/maps does not exist
|
|
1209 warning("Can't detect initial thread stack location - find_vma failed");
|
|
1210 // best effort: stack_start is normally within a few pages below the real
|
|
1211 // stack top, use it as stack top, and reduce stack size so we won't put
|
|
1212 // guard page outside stack.
|
|
1213 stack_top = stack_start;
|
|
1214 stack_size -= 16 * page_size();
|
|
1215 }
|
|
1216
|
|
1217 // stack_top could be partially down the page so align it
|
|
1218 stack_top = align_size_up(stack_top, page_size());
|
|
1219
|
|
1220 if (max_size && stack_size > max_size) {
|
|
1221 _initial_thread_stack_size = max_size;
|
|
1222 } else {
|
|
1223 _initial_thread_stack_size = stack_size;
|
|
1224 }
|
|
1225
|
|
1226 _initial_thread_stack_size = align_size_down(_initial_thread_stack_size, page_size());
|
|
1227 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size;
|
|
1228 }
|
|
1229
|
|
1230 ////////////////////////////////////////////////////////////////////////////////
|
|
1231 // time support
|
|
1232
|
|
1233 // Time since start-up in seconds to a fine granularity.
|
|
1234 // Used by VMSelfDestructTimer and the MemProfiler.
|
|
1235 double os::elapsedTime() {
|
|
1236
|
|
1237 return (double)(os::elapsed_counter()) * 0.000001;
|
|
1238 }
|
|
1239
|
|
1240 jlong os::elapsed_counter() {
|
|
1241 timeval time;
|
|
1242 int status = gettimeofday(&time, NULL);
|
|
1243 return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
|
|
1244 }
|
|
1245
|
|
1246 jlong os::elapsed_frequency() {
|
|
1247 return (1000 * 1000);
|
|
1248 }
|
|
1249
|
|
1250 jlong os::timeofday() {
|
|
1251 timeval time;
|
|
1252 int status = gettimeofday(&time, NULL);
|
|
1253 assert(status != -1, "linux error");
|
|
1254 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
|
|
1255 }
|
|
1256
|
|
1257 // Must return millis since Jan 1 1970 for JVM_CurrentTimeMillis
|
|
1258 // _use_global_time is only set if CacheTimeMillis is true
|
|
1259 jlong os::javaTimeMillis() {
|
|
1260 return (_use_global_time ? read_global_time() : timeofday());
|
|
1261 }
|
|
1262
|
|
1263 #ifndef CLOCK_MONOTONIC
|
|
1264 #define CLOCK_MONOTONIC (1)
|
|
1265 #endif
|
|
1266
|
|
1267 void os::Linux::clock_init() {
|
|
1268 // we do dlopen's in this particular order due to bug in linux
|
|
1269 // dynamical loader (see 6348968) leading to crash on exit
|
|
1270 void* handle = dlopen("librt.so.1", RTLD_LAZY);
|
|
1271 if (handle == NULL) {
|
|
1272 handle = dlopen("librt.so", RTLD_LAZY);
|
|
1273 }
|
|
1274
|
|
1275 if (handle) {
|
|
1276 int (*clock_getres_func)(clockid_t, struct timespec*) =
|
|
1277 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres");
|
|
1278 int (*clock_gettime_func)(clockid_t, struct timespec*) =
|
|
1279 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime");
|
|
1280 if (clock_getres_func && clock_gettime_func) {
|
|
1281 // See if monotonic clock is supported by the kernel. Note that some
|
|
1282 // early implementations simply return kernel jiffies (updated every
|
|
1283 // 1/100 or 1/1000 second). It would be bad to use such a low res clock
|
|
1284 // for nano time (though the monotonic property is still nice to have).
|
|
1285 // It's fixed in newer kernels, however clock_getres() still returns
|
|
1286 // 1/HZ. We check if clock_getres() works, but will ignore its reported
|
|
1287 // resolution for now. Hopefully as people move to new kernels, this
|
|
1288 // won't be a problem.
|
|
1289 struct timespec res;
|
|
1290 struct timespec tp;
|
|
1291 if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 &&
|
|
1292 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) {
|
|
1293 // yes, monotonic clock is supported
|
|
1294 _clock_gettime = clock_gettime_func;
|
|
1295 } else {
|
|
1296 // close librt if there is no monotonic clock
|
|
1297 dlclose(handle);
|
|
1298 }
|
|
1299 }
|
|
1300 }
|
|
1301 }
|
|
1302
|
|
1303 #ifndef SYS_clock_getres
|
|
1304
|
|
1305 #if defined(IA32) || defined(AMD64)
|
|
1306 #define SYS_clock_getres IA32_ONLY(266) AMD64_ONLY(229)
|
|
1307 #else
|
|
1308 #error Value of SYS_clock_getres not known on this platform
|
|
1309 #endif
|
|
1310
|
|
1311 #endif
|
|
1312
|
|
1313 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y)
|
|
1314
|
|
1315 void os::Linux::fast_thread_clock_init() {
|
|
1316 if (!UseLinuxPosixThreadCPUClocks) {
|
|
1317 return;
|
|
1318 }
|
|
1319 clockid_t clockid;
|
|
1320 struct timespec tp;
|
|
1321 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) =
|
|
1322 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid");
|
|
1323
|
|
1324 // Switch to using fast clocks for thread cpu time if
|
|
1325 // the sys_clock_getres() returns 0 error code.
|
|
1326 // Note, that some kernels may support the current thread
|
|
1327 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks
|
|
1328 // returned by the pthread_getcpuclockid().
|
|
1329 // If the fast Posix clocks are supported then the sys_clock_getres()
|
|
1330 // must return at least tp.tv_sec == 0 which means a resolution
|
|
1331 // better than 1 sec. This is extra check for reliability.
|
|
1332
|
|
1333 if(pthread_getcpuclockid_func &&
|
|
1334 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 &&
|
|
1335 sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) {
|
|
1336
|
|
1337 _supports_fast_thread_cpu_time = true;
|
|
1338 _pthread_getcpuclockid = pthread_getcpuclockid_func;
|
|
1339 }
|
|
1340 }
|
|
1341
|
|
1342 jlong os::javaTimeNanos() {
|
|
1343 if (Linux::supports_monotonic_clock()) {
|
|
1344 struct timespec tp;
|
|
1345 int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp);
|
|
1346 assert(status == 0, "gettime error");
|
|
1347 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
|
|
1348 return result;
|
|
1349 } else {
|
|
1350 timeval time;
|
|
1351 int status = gettimeofday(&time, NULL);
|
|
1352 assert(status != -1, "linux error");
|
|
1353 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
|
|
1354 return 1000 * usecs;
|
|
1355 }
|
|
1356 }
|
|
1357
|
|
1358 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
|
|
1359 if (Linux::supports_monotonic_clock()) {
|
|
1360 info_ptr->max_value = ALL_64_BITS;
|
|
1361
|
|
1362 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
|
|
1363 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
|
|
1364 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
|
|
1365 } else {
|
|
1366 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
|
|
1367 info_ptr->max_value = ALL_64_BITS;
|
|
1368
|
|
1369 // gettimeofday is a real time clock so it skips
|
|
1370 info_ptr->may_skip_backward = true;
|
|
1371 info_ptr->may_skip_forward = true;
|
|
1372 }
|
|
1373
|
|
1374 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
|
|
1375 }
|
|
1376
|
|
1377 // Return the real, user, and system times in seconds from an
|
|
1378 // arbitrary fixed point in the past.
|
|
1379 bool os::getTimesSecs(double* process_real_time,
|
|
1380 double* process_user_time,
|
|
1381 double* process_system_time) {
|
|
1382 struct tms ticks;
|
|
1383 clock_t real_ticks = times(&ticks);
|
|
1384
|
|
1385 if (real_ticks == (clock_t) (-1)) {
|
|
1386 return false;
|
|
1387 } else {
|
|
1388 double ticks_per_second = (double) clock_tics_per_sec;
|
|
1389 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
|
|
1390 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
|
|
1391 *process_real_time = ((double) real_ticks) / ticks_per_second;
|
|
1392
|
|
1393 return true;
|
|
1394 }
|
|
1395 }
|
|
1396
|
|
1397
|
|
1398 char * os::local_time_string(char *buf, size_t buflen) {
|
|
1399 struct tm t;
|
|
1400 time_t long_time;
|
|
1401 time(&long_time);
|
|
1402 localtime_r(&long_time, &t);
|
|
1403 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
|
|
1404 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
|
|
1405 t.tm_hour, t.tm_min, t.tm_sec);
|
|
1406 return buf;
|
|
1407 }
|
|
1408
|
|
1409 ////////////////////////////////////////////////////////////////////////////////
|
|
1410 // runtime exit support
|
|
1411
|
|
1412 // Note: os::shutdown() might be called very early during initialization, or
|
|
1413 // called from signal handler. Before adding something to os::shutdown(), make
|
|
1414 // sure it is async-safe and can handle partially initialized VM.
|
|
1415 void os::shutdown() {
|
|
1416
|
|
1417 // allow PerfMemory to attempt cleanup of any persistent resources
|
|
1418 perfMemory_exit();
|
|
1419
|
|
1420 // needs to remove object in file system
|
|
1421 AttachListener::abort();
|
|
1422
|
|
1423 // flush buffered output, finish log files
|
|
1424 ostream_abort();
|
|
1425
|
|
1426 // Check for abort hook
|
|
1427 abort_hook_t abort_hook = Arguments::abort_hook();
|
|
1428 if (abort_hook != NULL) {
|
|
1429 abort_hook();
|
|
1430 }
|
|
1431
|
|
1432 }
|
|
1433
|
|
1434 // Note: os::abort() might be called very early during initialization, or
|
|
1435 // called from signal handler. Before adding something to os::abort(), make
|
|
1436 // sure it is async-safe and can handle partially initialized VM.
|
|
1437 void os::abort(bool dump_core) {
|
|
1438 os::shutdown();
|
|
1439 if (dump_core) {
|
|
1440 #ifndef PRODUCT
|
|
1441 fdStream out(defaultStream::output_fd());
|
|
1442 out.print_raw("Current thread is ");
|
|
1443 char buf[16];
|
|
1444 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
|
|
1445 out.print_raw_cr(buf);
|
|
1446 out.print_raw_cr("Dumping core ...");
|
|
1447 #endif
|
|
1448 ::abort(); // dump core
|
|
1449 }
|
|
1450
|
|
1451 ::exit(1);
|
|
1452 }
|
|
1453
|
|
1454 // Die immediately, no exit hook, no abort hook, no cleanup.
|
|
1455 void os::die() {
|
|
1456 // _exit() on LinuxThreads only kills current thread
|
|
1457 ::abort();
|
|
1458 }
|
|
1459
|
|
1460 // unused on linux for now.
|
|
1461 void os::set_error_file(const char *logfile) {}
|
|
1462
|
|
1463 intx os::current_thread_id() { return (intx)pthread_self(); }
|
|
1464 int os::current_process_id() {
|
|
1465
|
|
1466 // Under the old linux thread library, linux gives each thread
|
|
1467 // its own process id. Because of this each thread will return
|
|
1468 // a different pid if this method were to return the result
|
|
1469 // of getpid(2). Linux provides no api that returns the pid
|
|
1470 // of the launcher thread for the vm. This implementation
|
|
1471 // returns a unique pid, the pid of the launcher thread
|
|
1472 // that starts the vm 'process'.
|
|
1473
|
|
1474 // Under the NPTL, getpid() returns the same pid as the
|
|
1475 // launcher thread rather than a unique pid per thread.
|
|
1476 // Use gettid() if you want the old pre NPTL behaviour.
|
|
1477
|
|
1478 // if you are looking for the result of a call to getpid() that
|
|
1479 // returns a unique pid for the calling thread, then look at the
|
|
1480 // OSThread::thread_id() method in osThread_linux.hpp file
|
|
1481
|
|
1482 return (int)(_initial_pid ? _initial_pid : getpid());
|
|
1483 }
|
|
1484
|
|
1485 // DLL functions
|
|
1486
|
|
1487 const char* os::dll_file_extension() { return ".so"; }
|
|
1488
|
|
1489 const char* os::get_temp_directory() { return "/tmp/"; }
|
|
1490
|
|
1491 const char* os::get_current_directory(char *buf, int buflen) {
|
|
1492 return getcwd(buf, buflen);
|
|
1493 }
|
|
1494
|
|
1495 // check if addr is inside libjvm[_g].so
|
|
1496 bool os::address_is_in_vm(address addr) {
|
|
1497 static address libjvm_base_addr;
|
|
1498 Dl_info dlinfo;
|
|
1499
|
|
1500 if (libjvm_base_addr == NULL) {
|
|
1501 dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo);
|
|
1502 libjvm_base_addr = (address)dlinfo.dli_fbase;
|
|
1503 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
|
|
1504 }
|
|
1505
|
|
1506 if (dladdr((void *)addr, &dlinfo)) {
|
|
1507 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
|
|
1508 }
|
|
1509
|
|
1510 return false;
|
|
1511 }
|
|
1512
|
|
1513 bool os::dll_address_to_function_name(address addr, char *buf,
|
|
1514 int buflen, int *offset) {
|
|
1515 Dl_info dlinfo;
|
|
1516
|
|
1517 if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) {
|
|
1518 if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
|
|
1519 if (offset) *offset = addr - (address)dlinfo.dli_saddr;
|
|
1520 return true;
|
|
1521 } else {
|
|
1522 if (buf) buf[0] = '\0';
|
|
1523 if (offset) *offset = -1;
|
|
1524 return false;
|
|
1525 }
|
|
1526 }
|
|
1527
|
|
1528 struct _address_to_library_name {
|
|
1529 address addr; // input : memory address
|
|
1530 size_t buflen; // size of fname
|
|
1531 char* fname; // output: library name
|
|
1532 address base; // library base addr
|
|
1533 };
|
|
1534
|
|
1535 static int address_to_library_name_callback(struct dl_phdr_info *info,
|
|
1536 size_t size, void *data) {
|
|
1537 int i;
|
|
1538 bool found = false;
|
|
1539 address libbase = NULL;
|
|
1540 struct _address_to_library_name * d = (struct _address_to_library_name *)data;
|
|
1541
|
|
1542 // iterate through all loadable segments
|
|
1543 for (i = 0; i < info->dlpi_phnum; i++) {
|
|
1544 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr);
|
|
1545 if (info->dlpi_phdr[i].p_type == PT_LOAD) {
|
|
1546 // base address of a library is the lowest address of its loaded
|
|
1547 // segments.
|
|
1548 if (libbase == NULL || libbase > segbase) {
|
|
1549 libbase = segbase;
|
|
1550 }
|
|
1551 // see if 'addr' is within current segment
|
|
1552 if (segbase <= d->addr &&
|
|
1553 d->addr < segbase + info->dlpi_phdr[i].p_memsz) {
|
|
1554 found = true;
|
|
1555 }
|
|
1556 }
|
|
1557 }
|
|
1558
|
|
1559 // dlpi_name is NULL or empty if the ELF file is executable, return 0
|
|
1560 // so dll_address_to_library_name() can fall through to use dladdr() which
|
|
1561 // can figure out executable name from argv[0].
|
|
1562 if (found && info->dlpi_name && info->dlpi_name[0]) {
|
|
1563 d->base = libbase;
|
|
1564 if (d->fname) {
|
|
1565 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name);
|
|
1566 }
|
|
1567 return 1;
|
|
1568 }
|
|
1569 return 0;
|
|
1570 }
|
|
1571
|
|
1572 bool os::dll_address_to_library_name(address addr, char* buf,
|
|
1573 int buflen, int* offset) {
|
|
1574 Dl_info dlinfo;
|
|
1575 struct _address_to_library_name data;
|
|
1576
|
|
1577 // There is a bug in old glibc dladdr() implementation that it could resolve
|
|
1578 // to wrong library name if the .so file has a base address != NULL. Here
|
|
1579 // we iterate through the program headers of all loaded libraries to find
|
|
1580 // out which library 'addr' really belongs to. This workaround can be
|
|
1581 // removed once the minimum requirement for glibc is moved to 2.3.x.
|
|
1582 data.addr = addr;
|
|
1583 data.fname = buf;
|
|
1584 data.buflen = buflen;
|
|
1585 data.base = NULL;
|
|
1586 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data);
|
|
1587
|
|
1588 if (rslt) {
|
|
1589 // buf already contains library name
|
|
1590 if (offset) *offset = addr - data.base;
|
|
1591 return true;
|
|
1592 } else if (dladdr((void*)addr, &dlinfo)){
|
|
1593 if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
|
|
1594 if (offset) *offset = addr - (address)dlinfo.dli_fbase;
|
|
1595 return true;
|
|
1596 } else {
|
|
1597 if (buf) buf[0] = '\0';
|
|
1598 if (offset) *offset = -1;
|
|
1599 return false;
|
|
1600 }
|
|
1601 }
|
|
1602
|
|
1603 // Loads .dll/.so and
|
|
1604 // in case of error it checks if .dll/.so was built for the
|
|
1605 // same architecture as Hotspot is running on
|
|
1606
|
|
1607 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
|
|
1608 {
|
|
1609 void * result= ::dlopen(filename, RTLD_LAZY);
|
|
1610 if (result != NULL) {
|
|
1611 // Successful loading
|
|
1612 return result;
|
|
1613 }
|
|
1614
|
|
1615 Elf32_Ehdr elf_head;
|
|
1616
|
|
1617 // Read system error message into ebuf
|
|
1618 // It may or may not be overwritten below
|
|
1619 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
|
|
1620 ebuf[ebuflen-1]='\0';
|
|
1621 int diag_msg_max_length=ebuflen-strlen(ebuf);
|
|
1622 char* diag_msg_buf=ebuf+strlen(ebuf);
|
|
1623
|
|
1624 if (diag_msg_max_length==0) {
|
|
1625 // No more space in ebuf for additional diagnostics message
|
|
1626 return NULL;
|
|
1627 }
|
|
1628
|
|
1629
|
|
1630 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
|
|
1631
|
|
1632 if (file_descriptor < 0) {
|
|
1633 // Can't open library, report dlerror() message
|
|
1634 return NULL;
|
|
1635 }
|
|
1636
|
|
1637 bool failed_to_read_elf_head=
|
|
1638 (sizeof(elf_head)!=
|
|
1639 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
|
|
1640
|
|
1641 ::close(file_descriptor);
|
|
1642 if (failed_to_read_elf_head) {
|
|
1643 // file i/o error - report dlerror() msg
|
|
1644 return NULL;
|
|
1645 }
|
|
1646
|
|
1647 typedef struct {
|
|
1648 Elf32_Half code; // Actual value as defined in elf.h
|
|
1649 Elf32_Half compat_class; // Compatibility of archs at VM's sense
|
|
1650 char elf_class; // 32 or 64 bit
|
|
1651 char endianess; // MSB or LSB
|
|
1652 char* name; // String representation
|
|
1653 } arch_t;
|
|
1654
|
|
1655 #ifndef EM_486
|
|
1656 #define EM_486 6 /* Intel 80486 */
|
|
1657 #endif
|
|
1658
|
|
1659 static const arch_t arch_array[]={
|
|
1660 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
|
|
1661 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
|
|
1662 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
|
|
1663 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
|
|
1664 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
|
|
1665 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
|
|
1666 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
|
|
1667 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
|
|
1668 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"}
|
|
1669 };
|
|
1670
|
|
1671 #if (defined IA32)
|
|
1672 static Elf32_Half running_arch_code=EM_386;
|
|
1673 #elif (defined AMD64)
|
|
1674 static Elf32_Half running_arch_code=EM_X86_64;
|
|
1675 #elif (defined IA64)
|
|
1676 static Elf32_Half running_arch_code=EM_IA_64;
|
|
1677 #elif (defined __sparc) && (defined _LP64)
|
|
1678 static Elf32_Half running_arch_code=EM_SPARCV9;
|
|
1679 #elif (defined __sparc) && (!defined _LP64)
|
|
1680 static Elf32_Half running_arch_code=EM_SPARC;
|
|
1681 #elif (defined __powerpc64__)
|
|
1682 static Elf32_Half running_arch_code=EM_PPC64;
|
|
1683 #elif (defined __powerpc__)
|
|
1684 static Elf32_Half running_arch_code=EM_PPC;
|
|
1685 #else
|
|
1686 #error Method os::dll_load requires that one of following is defined:\
|
|
1687 IA32, AMD64, IA64, __sparc, __powerpc__
|
|
1688 #endif
|
|
1689
|
|
1690 // Identify compatability class for VM's architecture and library's architecture
|
|
1691 // Obtain string descriptions for architectures
|
|
1692
|
|
1693 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
|
|
1694 int running_arch_index=-1;
|
|
1695
|
|
1696 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
|
|
1697 if (running_arch_code == arch_array[i].code) {
|
|
1698 running_arch_index = i;
|
|
1699 }
|
|
1700 if (lib_arch.code == arch_array[i].code) {
|
|
1701 lib_arch.compat_class = arch_array[i].compat_class;
|
|
1702 lib_arch.name = arch_array[i].name;
|
|
1703 }
|
|
1704 }
|
|
1705
|
|
1706 assert(running_arch_index != -1,
|
|
1707 "Didn't find running architecture code (running_arch_code) in arch_array");
|
|
1708 if (running_arch_index == -1) {
|
|
1709 // Even though running architecture detection failed
|
|
1710 // we may still continue with reporting dlerror() message
|
|
1711 return NULL;
|
|
1712 }
|
|
1713
|
|
1714 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
|
|
1715 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
|
|
1716 return NULL;
|
|
1717 }
|
|
1718
|
|
1719 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
|
|
1720 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
|
|
1721 return NULL;
|
|
1722 }
|
|
1723
|
|
1724 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
|
|
1725 if ( lib_arch.name!=NULL ) {
|
|
1726 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
|
|
1727 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
|
|
1728 lib_arch.name, arch_array[running_arch_index].name);
|
|
1729 } else {
|
|
1730 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
|
|
1731 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
|
|
1732 lib_arch.code,
|
|
1733 arch_array[running_arch_index].name);
|
|
1734 }
|
|
1735 }
|
|
1736
|
|
1737 return NULL;
|
|
1738 }
|
|
1739
|
|
1740
|
|
1741
|
|
1742
|
|
1743 bool _print_ascii_file(const char* filename, outputStream* st) {
|
|
1744 int fd = open(filename, O_RDONLY);
|
|
1745 if (fd == -1) {
|
|
1746 return false;
|
|
1747 }
|
|
1748
|
|
1749 char buf[32];
|
|
1750 int bytes;
|
|
1751 while ((bytes = read(fd, buf, sizeof(buf))) > 0) {
|
|
1752 st->print_raw(buf, bytes);
|
|
1753 }
|
|
1754
|
|
1755 close(fd);
|
|
1756
|
|
1757 return true;
|
|
1758 }
|
|
1759
|
|
1760 void os::print_dll_info(outputStream *st) {
|
|
1761 st->print_cr("Dynamic libraries:");
|
|
1762
|
|
1763 char fname[32];
|
|
1764 pid_t pid = os::Linux::gettid();
|
|
1765
|
|
1766 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid);
|
|
1767
|
|
1768 if (!_print_ascii_file(fname, st)) {
|
|
1769 st->print("Can not get library information for pid = %d\n", pid);
|
|
1770 }
|
|
1771 }
|
|
1772
|
|
1773
|
|
1774 void os::print_os_info(outputStream* st) {
|
|
1775 st->print("OS:");
|
|
1776
|
|
1777 // Try to identify popular distros.
|
|
1778 // Most Linux distributions have /etc/XXX-release file, which contains
|
|
1779 // the OS version string. Some have more than one /etc/XXX-release file
|
|
1780 // (e.g. Mandrake has both /etc/mandrake-release and /etc/redhat-release.),
|
|
1781 // so the order is important.
|
|
1782 if (!_print_ascii_file("/etc/mandrake-release", st) &&
|
|
1783 !_print_ascii_file("/etc/sun-release", st) &&
|
|
1784 !_print_ascii_file("/etc/redhat-release", st) &&
|
|
1785 !_print_ascii_file("/etc/SuSE-release", st) &&
|
|
1786 !_print_ascii_file("/etc/turbolinux-release", st) &&
|
|
1787 !_print_ascii_file("/etc/gentoo-release", st) &&
|
|
1788 !_print_ascii_file("/etc/debian_version", st)) {
|
|
1789 st->print("Linux");
|
|
1790 }
|
|
1791 st->cr();
|
|
1792
|
|
1793 // kernel
|
|
1794 st->print("uname:");
|
|
1795 struct utsname name;
|
|
1796 uname(&name);
|
|
1797 st->print(name.sysname); st->print(" ");
|
|
1798 st->print(name.release); st->print(" ");
|
|
1799 st->print(name.version); st->print(" ");
|
|
1800 st->print(name.machine);
|
|
1801 st->cr();
|
|
1802
|
|
1803 // Print warning if unsafe chroot environment detected
|
|
1804 if (unsafe_chroot_detected) {
|
|
1805 st->print("WARNING!! ");
|
|
1806 st->print_cr(unstable_chroot_error);
|
|
1807 }
|
|
1808
|
|
1809 // libc, pthread
|
|
1810 st->print("libc:");
|
|
1811 st->print(os::Linux::glibc_version()); st->print(" ");
|
|
1812 st->print(os::Linux::libpthread_version()); st->print(" ");
|
|
1813 if (os::Linux::is_LinuxThreads()) {
|
|
1814 st->print("(%s stack)", os::Linux::is_floating_stack() ? "floating" : "fixed");
|
|
1815 }
|
|
1816 st->cr();
|
|
1817
|
|
1818 // rlimit
|
|
1819 st->print("rlimit:");
|
|
1820 struct rlimit rlim;
|
|
1821
|
|
1822 st->print(" STACK ");
|
|
1823 getrlimit(RLIMIT_STACK, &rlim);
|
|
1824 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
|
|
1825 else st->print("%uk", rlim.rlim_cur >> 10);
|
|
1826
|
|
1827 st->print(", CORE ");
|
|
1828 getrlimit(RLIMIT_CORE, &rlim);
|
|
1829 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
|
|
1830 else st->print("%uk", rlim.rlim_cur >> 10);
|
|
1831
|
|
1832 st->print(", NPROC ");
|
|
1833 getrlimit(RLIMIT_NPROC, &rlim);
|
|
1834 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
|
|
1835 else st->print("%d", rlim.rlim_cur);
|
|
1836
|
|
1837 st->print(", NOFILE ");
|
|
1838 getrlimit(RLIMIT_NOFILE, &rlim);
|
|
1839 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
|
|
1840 else st->print("%d", rlim.rlim_cur);
|
|
1841
|
|
1842 st->print(", AS ");
|
|
1843 getrlimit(RLIMIT_AS, &rlim);
|
|
1844 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
|
|
1845 else st->print("%uk", rlim.rlim_cur >> 10);
|
|
1846 st->cr();
|
|
1847
|
|
1848 // load average
|
|
1849 st->print("load average:");
|
|
1850 double loadavg[3];
|
|
1851 os::loadavg(loadavg, 3);
|
|
1852 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
|
|
1853 st->cr();
|
|
1854 }
|
|
1855
|
|
1856 void os::print_memory_info(outputStream* st) {
|
|
1857
|
|
1858 st->print("Memory:");
|
|
1859 st->print(" %dk page", os::vm_page_size()>>10);
|
|
1860
|
|
1861 // values in struct sysinfo are "unsigned long"
|
|
1862 struct sysinfo si;
|
|
1863 sysinfo(&si);
|
|
1864
|
|
1865 st->print(", physical " UINT64_FORMAT "k",
|
|
1866 os::physical_memory() >> 10);
|
|
1867 st->print("(" UINT64_FORMAT "k free)",
|
|
1868 os::available_memory() >> 10);
|
|
1869 st->print(", swap " UINT64_FORMAT "k",
|
|
1870 ((jlong)si.totalswap * si.mem_unit) >> 10);
|
|
1871 st->print("(" UINT64_FORMAT "k free)",
|
|
1872 ((jlong)si.freeswap * si.mem_unit) >> 10);
|
|
1873 st->cr();
|
|
1874 }
|
|
1875
|
|
1876 // Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific
|
|
1877 // but they're the same for all the linux arch that we support
|
|
1878 // and they're the same for solaris but there's no common place to put this.
|
|
1879 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
|
|
1880 "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
|
|
1881 "ILL_COPROC", "ILL_BADSTK" };
|
|
1882
|
|
1883 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
|
|
1884 "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
|
|
1885 "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
|
|
1886
|
|
1887 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
|
|
1888
|
|
1889 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
|
|
1890
|
|
1891 void os::print_siginfo(outputStream* st, void* siginfo) {
|
|
1892 st->print("siginfo:");
|
|
1893
|
|
1894 const int buflen = 100;
|
|
1895 char buf[buflen];
|
|
1896 siginfo_t *si = (siginfo_t*)siginfo;
|
|
1897 st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
|
|
1898 if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
|
|
1899 st->print("si_errno=%s", buf);
|
|
1900 } else {
|
|
1901 st->print("si_errno=%d", si->si_errno);
|
|
1902 }
|
|
1903 const int c = si->si_code;
|
|
1904 assert(c > 0, "unexpected si_code");
|
|
1905 switch (si->si_signo) {
|
|
1906 case SIGILL:
|
|
1907 st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
|
|
1908 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
|
|
1909 break;
|
|
1910 case SIGFPE:
|
|
1911 st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
|
|
1912 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
|
|
1913 break;
|
|
1914 case SIGSEGV:
|
|
1915 st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
|
|
1916 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
|
|
1917 break;
|
|
1918 case SIGBUS:
|
|
1919 st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
|
|
1920 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
|
|
1921 break;
|
|
1922 default:
|
|
1923 st->print(", si_code=%d", si->si_code);
|
|
1924 // no si_addr
|
|
1925 }
|
|
1926
|
|
1927 if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
|
|
1928 UseSharedSpaces) {
|
|
1929 FileMapInfo* mapinfo = FileMapInfo::current_info();
|
|
1930 if (mapinfo->is_in_shared_space(si->si_addr)) {
|
|
1931 st->print("\n\nError accessing class data sharing archive." \
|
|
1932 " Mapped file inaccessible during execution, " \
|
|
1933 " possible disk/network problem.");
|
|
1934 }
|
|
1935 }
|
|
1936 st->cr();
|
|
1937 }
|
|
1938
|
|
1939
|
|
1940 static void print_signal_handler(outputStream* st, int sig,
|
|
1941 char* buf, size_t buflen);
|
|
1942
|
|
1943 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
|
|
1944 st->print_cr("Signal Handlers:");
|
|
1945 print_signal_handler(st, SIGSEGV, buf, buflen);
|
|
1946 print_signal_handler(st, SIGBUS , buf, buflen);
|
|
1947 print_signal_handler(st, SIGFPE , buf, buflen);
|
|
1948 print_signal_handler(st, SIGPIPE, buf, buflen);
|
|
1949 print_signal_handler(st, SIGXFSZ, buf, buflen);
|
|
1950 print_signal_handler(st, SIGILL , buf, buflen);
|
|
1951 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
|
|
1952 print_signal_handler(st, SR_signum, buf, buflen);
|
|
1953 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
|
|
1954 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
|
|
1955 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
|
|
1956 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
|
|
1957 }
|
|
1958
|
|
1959 static char saved_jvm_path[MAXPATHLEN] = {0};
|
|
1960
|
|
1961 // Find the full path to the current module, libjvm.so or libjvm_g.so
|
|
1962 void os::jvm_path(char *buf, jint len) {
|
|
1963 // Error checking.
|
|
1964 if (len < MAXPATHLEN) {
|
|
1965 assert(false, "must use a large-enough buffer");
|
|
1966 buf[0] = '\0';
|
|
1967 return;
|
|
1968 }
|
|
1969 // Lazy resolve the path to current module.
|
|
1970 if (saved_jvm_path[0] != 0) {
|
|
1971 strcpy(buf, saved_jvm_path);
|
|
1972 return;
|
|
1973 }
|
|
1974
|
|
1975 char dli_fname[MAXPATHLEN];
|
|
1976 bool ret = dll_address_to_library_name(
|
|
1977 CAST_FROM_FN_PTR(address, os::jvm_path),
|
|
1978 dli_fname, sizeof(dli_fname), NULL);
|
|
1979 assert(ret != 0, "cannot locate libjvm");
|
|
1980 realpath(dli_fname, buf);
|
|
1981
|
|
1982 if (strcmp(Arguments::sun_java_launcher(), "gamma") == 0) {
|
|
1983 // Support for the gamma launcher. Typical value for buf is
|
|
1984 // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so". If "/jre/lib/" appears at
|
|
1985 // the right place in the string, then assume we are installed in a JDK and
|
|
1986 // we're done. Otherwise, check for a JAVA_HOME environment variable and fix
|
|
1987 // up the path so it looks like libjvm.so is installed there (append a
|
|
1988 // fake suffix hotspot/libjvm.so).
|
|
1989 const char *p = buf + strlen(buf) - 1;
|
|
1990 for (int count = 0; p > buf && count < 5; ++count) {
|
|
1991 for (--p; p > buf && *p != '/'; --p)
|
|
1992 /* empty */ ;
|
|
1993 }
|
|
1994
|
|
1995 if (strncmp(p, "/jre/lib/", 9) != 0) {
|
|
1996 // Look for JAVA_HOME in the environment.
|
|
1997 char* java_home_var = ::getenv("JAVA_HOME");
|
|
1998 if (java_home_var != NULL && java_home_var[0] != 0) {
|
|
1999 // Check the current module name "libjvm.so" or "libjvm_g.so".
|
|
2000 p = strrchr(buf, '/');
|
|
2001 assert(strstr(p, "/libjvm") == p, "invalid library name");
|
|
2002 p = strstr(p, "_g") ? "_g" : "";
|
|
2003
|
|
2004 realpath(java_home_var, buf);
|
|
2005 sprintf(buf + strlen(buf), "/jre/lib/%s", cpu_arch);
|
|
2006 if (0 == access(buf, F_OK)) {
|
|
2007 // Use current module name "libjvm[_g].so" instead of
|
|
2008 // "libjvm"debug_only("_g")".so" since for fastdebug version
|
|
2009 // we should have "libjvm.so" but debug_only("_g") adds "_g"!
|
|
2010 // It is used when we are choosing the HPI library's name
|
|
2011 // "libhpi[_g].so" in hpi::initialize_get_interface().
|
|
2012 sprintf(buf + strlen(buf), "/hotspot/libjvm%s.so", p);
|
|
2013 } else {
|
|
2014 // Go back to path of .so
|
|
2015 realpath(dli_fname, buf);
|
|
2016 }
|
|
2017 }
|
|
2018 }
|
|
2019 }
|
|
2020
|
|
2021 strcpy(saved_jvm_path, buf);
|
|
2022 }
|
|
2023
|
|
2024 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
|
|
2025 // no prefix required, not even "_"
|
|
2026 }
|
|
2027
|
|
2028 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
|
|
2029 // no suffix required
|
|
2030 }
|
|
2031
|
|
2032 ////////////////////////////////////////////////////////////////////////////////
|
|
2033 // sun.misc.Signal support
|
|
2034
|
|
2035 static volatile jint sigint_count = 0;
|
|
2036
|
|
2037 static void
|
|
2038 UserHandler(int sig, void *siginfo, void *context) {
|
|
2039 // 4511530 - sem_post is serialized and handled by the manager thread. When
|
|
2040 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
|
|
2041 // don't want to flood the manager thread with sem_post requests.
|
|
2042 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
|
|
2043 return;
|
|
2044
|
|
2045 // Ctrl-C is pressed during error reporting, likely because the error
|
|
2046 // handler fails to abort. Let VM die immediately.
|
|
2047 if (sig == SIGINT && is_error_reported()) {
|
|
2048 os::die();
|
|
2049 }
|
|
2050
|
|
2051 os::signal_notify(sig);
|
|
2052 }
|
|
2053
|
|
2054 void* os::user_handler() {
|
|
2055 return CAST_FROM_FN_PTR(void*, UserHandler);
|
|
2056 }
|
|
2057
|
|
2058 extern "C" {
|
|
2059 typedef void (*sa_handler_t)(int);
|
|
2060 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
|
|
2061 }
|
|
2062
|
|
2063 void* os::signal(int signal_number, void* handler) {
|
|
2064 struct sigaction sigAct, oldSigAct;
|
|
2065
|
|
2066 sigfillset(&(sigAct.sa_mask));
|
|
2067 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
|
|
2068 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
|
|
2069
|
|
2070 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
|
|
2071 // -1 means registration failed
|
|
2072 return (void *)-1;
|
|
2073 }
|
|
2074
|
|
2075 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
|
|
2076 }
|
|
2077
|
|
2078 void os::signal_raise(int signal_number) {
|
|
2079 ::raise(signal_number);
|
|
2080 }
|
|
2081
|
|
2082 /*
|
|
2083 * The following code is moved from os.cpp for making this
|
|
2084 * code platform specific, which it is by its very nature.
|
|
2085 */
|
|
2086
|
|
2087 // Will be modified when max signal is changed to be dynamic
|
|
2088 int os::sigexitnum_pd() {
|
|
2089 return NSIG;
|
|
2090 }
|
|
2091
|
|
2092 // a counter for each possible signal value
|
|
2093 static volatile jint pending_signals[NSIG+1] = { 0 };
|
|
2094
|
|
2095 // Linux(POSIX) specific hand shaking semaphore.
|
|
2096 static sem_t sig_sem;
|
|
2097
|
|
2098 void os::signal_init_pd() {
|
|
2099 // Initialize signal structures
|
|
2100 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
|
|
2101
|
|
2102 // Initialize signal semaphore
|
|
2103 ::sem_init(&sig_sem, 0, 0);
|
|
2104 }
|
|
2105
|
|
2106 void os::signal_notify(int sig) {
|
|
2107 Atomic::inc(&pending_signals[sig]);
|
|
2108 ::sem_post(&sig_sem);
|
|
2109 }
|
|
2110
|
|
2111 static int check_pending_signals(bool wait) {
|
|
2112 Atomic::store(0, &sigint_count);
|
|
2113 for (;;) {
|
|
2114 for (int i = 0; i < NSIG + 1; i++) {
|
|
2115 jint n = pending_signals[i];
|
|
2116 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
|
|
2117 return i;
|
|
2118 }
|
|
2119 }
|
|
2120 if (!wait) {
|
|
2121 return -1;
|
|
2122 }
|
|
2123 JavaThread *thread = JavaThread::current();
|
|
2124 ThreadBlockInVM tbivm(thread);
|
|
2125
|
|
2126 bool threadIsSuspended;
|
|
2127 do {
|
|
2128 thread->set_suspend_equivalent();
|
|
2129 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
|
|
2130 ::sem_wait(&sig_sem);
|
|
2131
|
|
2132 // were we externally suspended while we were waiting?
|
|
2133 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
|
|
2134 if (threadIsSuspended) {
|
|
2135 //
|
|
2136 // The semaphore has been incremented, but while we were waiting
|
|
2137 // another thread suspended us. We don't want to continue running
|
|
2138 // while suspended because that would surprise the thread that
|
|
2139 // suspended us.
|
|
2140 //
|
|
2141 ::sem_post(&sig_sem);
|
|
2142
|
|
2143 thread->java_suspend_self();
|
|
2144 }
|
|
2145 } while (threadIsSuspended);
|
|
2146 }
|
|
2147 }
|
|
2148
|
|
2149 int os::signal_lookup() {
|
|
2150 return check_pending_signals(false);
|
|
2151 }
|
|
2152
|
|
2153 int os::signal_wait() {
|
|
2154 return check_pending_signals(true);
|
|
2155 }
|
|
2156
|
|
2157 ////////////////////////////////////////////////////////////////////////////////
|
|
2158 // Virtual Memory
|
|
2159
|
|
2160 int os::vm_page_size() {
|
|
2161 // Seems redundant as all get out
|
|
2162 assert(os::Linux::page_size() != -1, "must call os::init");
|
|
2163 return os::Linux::page_size();
|
|
2164 }
|
|
2165
|
|
2166 // Solaris allocates memory by pages.
|
|
2167 int os::vm_allocation_granularity() {
|
|
2168 assert(os::Linux::page_size() != -1, "must call os::init");
|
|
2169 return os::Linux::page_size();
|
|
2170 }
|
|
2171
|
|
2172 // Rationale behind this function:
|
|
2173 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
|
|
2174 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
|
|
2175 // samples for JITted code. Here we create private executable mapping over the code cache
|
|
2176 // and then we can use standard (well, almost, as mapping can change) way to provide
|
|
2177 // info for the reporting script by storing timestamp and location of symbol
|
|
2178 void linux_wrap_code(char* base, size_t size) {
|
|
2179 static volatile jint cnt = 0;
|
|
2180
|
|
2181 if (!UseOprofile) {
|
|
2182 return;
|
|
2183 }
|
|
2184
|
|
2185 char buf[40];
|
|
2186 int num = Atomic::add(1, &cnt);
|
|
2187
|
|
2188 sprintf(buf, "/tmp/hs-vm-%d-%d", os::current_process_id(), num);
|
|
2189 unlink(buf);
|
|
2190
|
|
2191 int fd = open(buf, O_CREAT | O_RDWR, S_IRWXU);
|
|
2192
|
|
2193 if (fd != -1) {
|
|
2194 off_t rv = lseek(fd, size-2, SEEK_SET);
|
|
2195 if (rv != (off_t)-1) {
|
|
2196 if (write(fd, "", 1) == 1) {
|
|
2197 mmap(base, size,
|
|
2198 PROT_READ|PROT_WRITE|PROT_EXEC,
|
|
2199 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
|
|
2200 }
|
|
2201 }
|
|
2202 close(fd);
|
|
2203 unlink(buf);
|
|
2204 }
|
|
2205 }
|
|
2206
|
|
2207 // NOTE: Linux kernel does not really reserve the pages for us.
|
|
2208 // All it does is to check if there are enough free pages
|
|
2209 // left at the time of mmap(). This could be a potential
|
|
2210 // problem.
|
|
2211 bool os::commit_memory(char* addr, size_t size) {
|
|
2212 uintptr_t res = (uintptr_t) ::mmap(addr, size,
|
|
2213 PROT_READ|PROT_WRITE|PROT_EXEC,
|
|
2214 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
|
|
2215 return res != (uintptr_t) MAP_FAILED;
|
|
2216 }
|
|
2217
|
|
2218 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint) {
|
|
2219 return commit_memory(addr, size);
|
|
2220 }
|
|
2221
|
|
2222 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { }
|
|
2223 void os::free_memory(char *addr, size_t bytes) { }
|
|
2224 void os::numa_make_global(char *addr, size_t bytes) { }
|
|
2225 void os::numa_make_local(char *addr, size_t bytes) { }
|
|
2226 bool os::numa_topology_changed() { return false; }
|
|
2227 size_t os::numa_get_groups_num() { return 1; }
|
|
2228 int os::numa_get_group_id() { return 0; }
|
|
2229 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
|
|
2230 if (size > 0) {
|
|
2231 ids[0] = 0;
|
|
2232 return 1;
|
|
2233 }
|
|
2234 return 0;
|
|
2235 }
|
|
2236
|
|
2237 bool os::get_page_info(char *start, page_info* info) {
|
|
2238 return false;
|
|
2239 }
|
|
2240
|
|
2241 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
|
|
2242 return end;
|
|
2243 }
|
|
2244
|
|
2245 bool os::uncommit_memory(char* addr, size_t size) {
|
|
2246 return ::mmap(addr, size,
|
|
2247 PROT_READ|PROT_WRITE|PROT_EXEC,
|
|
2248 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0)
|
|
2249 != MAP_FAILED;
|
|
2250 }
|
|
2251
|
|
2252 static address _highest_vm_reserved_address = NULL;
|
|
2253
|
|
2254 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
|
|
2255 // at 'requested_addr'. If there are existing memory mappings at the same
|
|
2256 // location, however, they will be overwritten. If 'fixed' is false,
|
|
2257 // 'requested_addr' is only treated as a hint, the return value may or
|
|
2258 // may not start from the requested address. Unlike Linux mmap(), this
|
|
2259 // function returns NULL to indicate failure.
|
|
2260 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
|
|
2261 char * addr;
|
|
2262 int flags;
|
|
2263
|
|
2264 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
|
|
2265 if (fixed) {
|
|
2266 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address");
|
|
2267 flags |= MAP_FIXED;
|
|
2268 }
|
|
2269
|
|
2270 addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE|PROT_EXEC,
|
|
2271 flags, -1, 0);
|
|
2272
|
|
2273 if (addr != MAP_FAILED) {
|
|
2274 // anon_mmap() should only get called during VM initialization,
|
|
2275 // don't need lock (actually we can skip locking even it can be called
|
|
2276 // from multiple threads, because _highest_vm_reserved_address is just a
|
|
2277 // hint about the upper limit of non-stack memory regions.)
|
|
2278 if ((address)addr + bytes > _highest_vm_reserved_address) {
|
|
2279 _highest_vm_reserved_address = (address)addr + bytes;
|
|
2280 }
|
|
2281 }
|
|
2282
|
|
2283 return addr == MAP_FAILED ? NULL : addr;
|
|
2284 }
|
|
2285
|
|
2286 // Don't update _highest_vm_reserved_address, because there might be memory
|
|
2287 // regions above addr + size. If so, releasing a memory region only creates
|
|
2288 // a hole in the address space, it doesn't help prevent heap-stack collision.
|
|
2289 //
|
|
2290 static int anon_munmap(char * addr, size_t size) {
|
|
2291 return ::munmap(addr, size) == 0;
|
|
2292 }
|
|
2293
|
|
2294 char* os::reserve_memory(size_t bytes, char* requested_addr,
|
|
2295 size_t alignment_hint) {
|
|
2296 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
|
|
2297 }
|
|
2298
|
|
2299 bool os::release_memory(char* addr, size_t size) {
|
|
2300 return anon_munmap(addr, size);
|
|
2301 }
|
|
2302
|
|
2303 static address highest_vm_reserved_address() {
|
|
2304 return _highest_vm_reserved_address;
|
|
2305 }
|
|
2306
|
|
2307 static bool linux_mprotect(char* addr, size_t size, int prot) {
|
|
2308 // Linux wants the mprotect address argument to be page aligned.
|
|
2309 char* bottom = (char*)align_size_down((intptr_t)addr, os::Linux::page_size());
|
|
2310
|
|
2311 // According to SUSv3, mprotect() should only be used with mappings
|
|
2312 // established by mmap(), and mmap() always maps whole pages. Unaligned
|
|
2313 // 'addr' likely indicates problem in the VM (e.g. trying to change
|
|
2314 // protection of malloc'ed or statically allocated memory). Check the
|
|
2315 // caller if you hit this assert.
|
|
2316 assert(addr == bottom, "sanity check");
|
|
2317
|
|
2318 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size());
|
|
2319 return ::mprotect(bottom, size, prot) == 0;
|
|
2320 }
|
|
2321
|
|
2322 bool os::protect_memory(char* addr, size_t size) {
|
|
2323 return linux_mprotect(addr, size, PROT_READ);
|
|
2324 }
|
|
2325
|
|
2326 bool os::guard_memory(char* addr, size_t size) {
|
|
2327 return linux_mprotect(addr, size, PROT_NONE);
|
|
2328 }
|
|
2329
|
|
2330 bool os::unguard_memory(char* addr, size_t size) {
|
|
2331 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE|PROT_EXEC);
|
|
2332 }
|
|
2333
|
|
2334 // Large page support
|
|
2335
|
|
2336 static size_t _large_page_size = 0;
|
|
2337
|
|
2338 bool os::large_page_init() {
|
|
2339 if (!UseLargePages) return false;
|
|
2340
|
|
2341 if (LargePageSizeInBytes) {
|
|
2342 _large_page_size = LargePageSizeInBytes;
|
|
2343 } else {
|
|
2344 // large_page_size on Linux is used to round up heap size. x86 uses either
|
|
2345 // 2M or 4M page, depending on whether PAE (Physical Address Extensions)
|
|
2346 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use
|
|
2347 // page as large as 256M.
|
|
2348 //
|
|
2349 // Here we try to figure out page size by parsing /proc/meminfo and looking
|
|
2350 // for a line with the following format:
|
|
2351 // Hugepagesize: 2048 kB
|
|
2352 //
|
|
2353 // If we can't determine the value (e.g. /proc is not mounted, or the text
|
|
2354 // format has been changed), we'll use the largest page size supported by
|
|
2355 // the processor.
|
|
2356
|
|
2357 _large_page_size = IA32_ONLY(4 * M) AMD64_ONLY(2 * M) IA64_ONLY(256 * M) SPARC_ONLY(4 * M);
|
|
2358
|
|
2359 FILE *fp = fopen("/proc/meminfo", "r");
|
|
2360 if (fp) {
|
|
2361 while (!feof(fp)) {
|
|
2362 int x = 0;
|
|
2363 char buf[16];
|
|
2364 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) {
|
|
2365 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) {
|
|
2366 _large_page_size = x * K;
|
|
2367 break;
|
|
2368 }
|
|
2369 } else {
|
|
2370 // skip to next line
|
|
2371 for (;;) {
|
|
2372 int ch = fgetc(fp);
|
|
2373 if (ch == EOF || ch == (int)'\n') break;
|
|
2374 }
|
|
2375 }
|
|
2376 }
|
|
2377 fclose(fp);
|
|
2378 }
|
|
2379 }
|
|
2380
|
|
2381 const size_t default_page_size = (size_t)Linux::page_size();
|
|
2382 if (_large_page_size > default_page_size) {
|
|
2383 _page_sizes[0] = _large_page_size;
|
|
2384 _page_sizes[1] = default_page_size;
|
|
2385 _page_sizes[2] = 0;
|
|
2386 }
|
|
2387
|
|
2388 // Large page support is available on 2.6 or newer kernel, some vendors
|
|
2389 // (e.g. Redhat) have backported it to their 2.4 based distributions.
|
|
2390 // We optimistically assume the support is available. If later it turns out
|
|
2391 // not true, VM will automatically switch to use regular page size.
|
|
2392 return true;
|
|
2393 }
|
|
2394
|
|
2395 #ifndef SHM_HUGETLB
|
|
2396 #define SHM_HUGETLB 04000
|
|
2397 #endif
|
|
2398
|
|
2399 char* os::reserve_memory_special(size_t bytes) {
|
|
2400 assert(UseLargePages, "only for large pages");
|
|
2401
|
|
2402 key_t key = IPC_PRIVATE;
|
|
2403 char *addr;
|
|
2404
|
|
2405 bool warn_on_failure = UseLargePages &&
|
|
2406 (!FLAG_IS_DEFAULT(UseLargePages) ||
|
|
2407 !FLAG_IS_DEFAULT(LargePageSizeInBytes)
|
|
2408 );
|
|
2409 char msg[128];
|
|
2410
|
|
2411 // Create a large shared memory region to attach to based on size.
|
|
2412 // Currently, size is the total size of the heap
|
|
2413 int shmid = shmget(key, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W);
|
|
2414 if (shmid == -1) {
|
|
2415 // Possible reasons for shmget failure:
|
|
2416 // 1. shmmax is too small for Java heap.
|
|
2417 // > check shmmax value: cat /proc/sys/kernel/shmmax
|
|
2418 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
|
|
2419 // 2. not enough large page memory.
|
|
2420 // > check available large pages: cat /proc/meminfo
|
|
2421 // > increase amount of large pages:
|
|
2422 // echo new_value > /proc/sys/vm/nr_hugepages
|
|
2423 // Note 1: different Linux may use different name for this property,
|
|
2424 // e.g. on Redhat AS-3 it is "hugetlb_pool".
|
|
2425 // Note 2: it's possible there's enough physical memory available but
|
|
2426 // they are so fragmented after a long run that they can't
|
|
2427 // coalesce into large pages. Try to reserve large pages when
|
|
2428 // the system is still "fresh".
|
|
2429 if (warn_on_failure) {
|
|
2430 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
|
|
2431 warning(msg);
|
|
2432 }
|
|
2433 return NULL;
|
|
2434 }
|
|
2435
|
|
2436 // attach to the region
|
|
2437 addr = (char*)shmat(shmid, NULL, 0);
|
|
2438 int err = errno;
|
|
2439
|
|
2440 // Remove shmid. If shmat() is successful, the actual shared memory segment
|
|
2441 // will be deleted when it's detached by shmdt() or when the process
|
|
2442 // terminates. If shmat() is not successful this will remove the shared
|
|
2443 // segment immediately.
|
|
2444 shmctl(shmid, IPC_RMID, NULL);
|
|
2445
|
|
2446 if ((intptr_t)addr == -1) {
|
|
2447 if (warn_on_failure) {
|
|
2448 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
|
|
2449 warning(msg);
|
|
2450 }
|
|
2451 return NULL;
|
|
2452 }
|
|
2453
|
|
2454 return addr;
|
|
2455 }
|
|
2456
|
|
2457 bool os::release_memory_special(char* base, size_t bytes) {
|
|
2458 // detaching the SHM segment will also delete it, see reserve_memory_special()
|
|
2459 int rslt = shmdt(base);
|
|
2460 return rslt == 0;
|
|
2461 }
|
|
2462
|
|
2463 size_t os::large_page_size() {
|
|
2464 return _large_page_size;
|
|
2465 }
|
|
2466
|
|
2467 // Linux does not support anonymous mmap with large page memory. The only way
|
|
2468 // to reserve large page memory without file backing is through SysV shared
|
|
2469 // memory API. The entire memory region is committed and pinned upfront.
|
|
2470 // Hopefully this will change in the future...
|
|
2471 bool os::can_commit_large_page_memory() {
|
|
2472 return false;
|
|
2473 }
|
|
2474
|
|
2475 // Reserve memory at an arbitrary address, only if that area is
|
|
2476 // available (and not reserved for something else).
|
|
2477
|
|
2478 char* os::attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
|
|
2479 const int max_tries = 10;
|
|
2480 char* base[max_tries];
|
|
2481 size_t size[max_tries];
|
|
2482 const size_t gap = 0x000000;
|
|
2483
|
|
2484 // Assert only that the size is a multiple of the page size, since
|
|
2485 // that's all that mmap requires, and since that's all we really know
|
|
2486 // about at this low abstraction level. If we need higher alignment,
|
|
2487 // we can either pass an alignment to this method or verify alignment
|
|
2488 // in one of the methods further up the call chain. See bug 5044738.
|
|
2489 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
|
|
2490
|
|
2491 // Repeatedly allocate blocks until the block is allocated at the
|
|
2492 // right spot. Give up after max_tries. Note that reserve_memory() will
|
|
2493 // automatically update _highest_vm_reserved_address if the call is
|
|
2494 // successful. The variable tracks the highest memory address every reserved
|
|
2495 // by JVM. It is used to detect heap-stack collision if running with
|
|
2496 // fixed-stack LinuxThreads. Because here we may attempt to reserve more
|
|
2497 // space than needed, it could confuse the collision detecting code. To
|
|
2498 // solve the problem, save current _highest_vm_reserved_address and
|
|
2499 // calculate the correct value before return.
|
|
2500 address old_highest = _highest_vm_reserved_address;
|
|
2501
|
|
2502 // Linux mmap allows caller to pass an address as hint; give it a try first,
|
|
2503 // if kernel honors the hint then we can return immediately.
|
|
2504 char * addr = anon_mmap(requested_addr, bytes, false);
|
|
2505 if (addr == requested_addr) {
|
|
2506 return requested_addr;
|
|
2507 }
|
|
2508
|
|
2509 if (addr != NULL) {
|
|
2510 // mmap() is successful but it fails to reserve at the requested address
|
|
2511 anon_munmap(addr, bytes);
|
|
2512 }
|
|
2513
|
|
2514 int i;
|
|
2515 for (i = 0; i < max_tries; ++i) {
|
|
2516 base[i] = reserve_memory(bytes);
|
|
2517
|
|
2518 if (base[i] != NULL) {
|
|
2519 // Is this the block we wanted?
|
|
2520 if (base[i] == requested_addr) {
|
|
2521 size[i] = bytes;
|
|
2522 break;
|
|
2523 }
|
|
2524
|
|
2525 // Does this overlap the block we wanted? Give back the overlapped
|
|
2526 // parts and try again.
|
|
2527
|
|
2528 size_t top_overlap = requested_addr + (bytes + gap) - base[i];
|
|
2529 if (top_overlap >= 0 && top_overlap < bytes) {
|
|
2530 unmap_memory(base[i], top_overlap);
|
|
2531 base[i] += top_overlap;
|
|
2532 size[i] = bytes - top_overlap;
|
|
2533 } else {
|
|
2534 size_t bottom_overlap = base[i] + bytes - requested_addr;
|
|
2535 if (bottom_overlap >= 0 && bottom_overlap < bytes) {
|
|
2536 unmap_memory(requested_addr, bottom_overlap);
|
|
2537 size[i] = bytes - bottom_overlap;
|
|
2538 } else {
|
|
2539 size[i] = bytes;
|
|
2540 }
|
|
2541 }
|
|
2542 }
|
|
2543 }
|
|
2544
|
|
2545 // Give back the unused reserved pieces.
|
|
2546
|
|
2547 for (int j = 0; j < i; ++j) {
|
|
2548 if (base[j] != NULL) {
|
|
2549 unmap_memory(base[j], size[j]);
|
|
2550 }
|
|
2551 }
|
|
2552
|
|
2553 if (i < max_tries) {
|
|
2554 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
|
|
2555 return requested_addr;
|
|
2556 } else {
|
|
2557 _highest_vm_reserved_address = old_highest;
|
|
2558 return NULL;
|
|
2559 }
|
|
2560 }
|
|
2561
|
|
2562 size_t os::read(int fd, void *buf, unsigned int nBytes) {
|
|
2563 return ::read(fd, buf, nBytes);
|
|
2564 }
|
|
2565
|
|
2566 // TODO-FIXME: reconcile Solaris' os::sleep with the linux variation.
|
|
2567 // Solaris uses poll(), linux uses park().
|
|
2568 // Poll() is likely a better choice, assuming that Thread.interrupt()
|
|
2569 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
|
|
2570 // SIGSEGV, see 4355769.
|
|
2571
|
|
2572 const int NANOSECS_PER_MILLISECS = 1000000;
|
|
2573
|
|
2574 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
|
|
2575 assert(thread == Thread::current(), "thread consistency check");
|
|
2576
|
|
2577 ParkEvent * const slp = thread->_SleepEvent ;
|
|
2578 slp->reset() ;
|
|
2579 OrderAccess::fence() ;
|
|
2580
|
|
2581 if (interruptible) {
|
|
2582 jlong prevtime = javaTimeNanos();
|
|
2583
|
|
2584 for (;;) {
|
|
2585 if (os::is_interrupted(thread, true)) {
|
|
2586 return OS_INTRPT;
|
|
2587 }
|
|
2588
|
|
2589 jlong newtime = javaTimeNanos();
|
|
2590
|
|
2591 if (newtime - prevtime < 0) {
|
|
2592 // time moving backwards, should only happen if no monotonic clock
|
|
2593 // not a guarantee() because JVM should not abort on kernel/glibc bugs
|
|
2594 assert(!Linux::supports_monotonic_clock(), "time moving backwards");
|
|
2595 } else {
|
|
2596 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISECS;
|
|
2597 }
|
|
2598
|
|
2599 if(millis <= 0) {
|
|
2600 return OS_OK;
|
|
2601 }
|
|
2602
|
|
2603 prevtime = newtime;
|
|
2604
|
|
2605 {
|
|
2606 assert(thread->is_Java_thread(), "sanity check");
|
|
2607 JavaThread *jt = (JavaThread *) thread;
|
|
2608 ThreadBlockInVM tbivm(jt);
|
|
2609 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
|
|
2610
|
|
2611 jt->set_suspend_equivalent();
|
|
2612 // cleared by handle_special_suspend_equivalent_condition() or
|
|
2613 // java_suspend_self() via check_and_wait_while_suspended()
|
|
2614
|
|
2615 slp->park(millis);
|
|
2616
|
|
2617 // were we externally suspended while we were waiting?
|
|
2618 jt->check_and_wait_while_suspended();
|
|
2619 }
|
|
2620 }
|
|
2621 } else {
|
|
2622 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
|
|
2623 jlong prevtime = javaTimeNanos();
|
|
2624
|
|
2625 for (;;) {
|
|
2626 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
|
|
2627 // the 1st iteration ...
|
|
2628 jlong newtime = javaTimeNanos();
|
|
2629
|
|
2630 if (newtime - prevtime < 0) {
|
|
2631 // time moving backwards, should only happen if no monotonic clock
|
|
2632 // not a guarantee() because JVM should not abort on kernel/glibc bugs
|
|
2633 assert(!Linux::supports_monotonic_clock(), "time moving backwards");
|
|
2634 } else {
|
|
2635 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISECS;
|
|
2636 }
|
|
2637
|
|
2638 if(millis <= 0) break ;
|
|
2639
|
|
2640 prevtime = newtime;
|
|
2641 slp->park(millis);
|
|
2642 }
|
|
2643 return OS_OK ;
|
|
2644 }
|
|
2645 }
|
|
2646
|
|
2647 int os::naked_sleep() {
|
|
2648 // %% make the sleep time an integer flag. for now use 1 millisec.
|
|
2649 return os::sleep(Thread::current(), 1, false);
|
|
2650 }
|
|
2651
|
|
2652 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
|
|
2653 void os::infinite_sleep() {
|
|
2654 while (true) { // sleep forever ...
|
|
2655 ::sleep(100); // ... 100 seconds at a time
|
|
2656 }
|
|
2657 }
|
|
2658
|
|
2659 // Used to convert frequent JVM_Yield() to nops
|
|
2660 bool os::dont_yield() {
|
|
2661 return DontYieldALot;
|
|
2662 }
|
|
2663
|
|
2664 void os::yield() {
|
|
2665 sched_yield();
|
|
2666 }
|
|
2667
|
|
2668 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
|
|
2669
|
|
2670 void os::yield_all(int attempts) {
|
|
2671 // Yields to all threads, including threads with lower priorities
|
|
2672 // Threads on Linux are all with same priority. The Solaris style
|
|
2673 // os::yield_all() with nanosleep(1ms) is not necessary.
|
|
2674 sched_yield();
|
|
2675 }
|
|
2676
|
|
2677 // Called from the tight loops to possibly influence time-sharing heuristics
|
|
2678 void os::loop_breaker(int attempts) {
|
|
2679 os::yield_all(attempts);
|
|
2680 }
|
|
2681
|
|
2682 ////////////////////////////////////////////////////////////////////////////////
|
|
2683 // thread priority support
|
|
2684
|
|
2685 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER
|
|
2686 // only supports dynamic priority, static priority must be zero. For real-time
|
|
2687 // applications, Linux supports SCHED_RR which allows static priority (1-99).
|
|
2688 // However, for large multi-threaded applications, SCHED_RR is not only slower
|
|
2689 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
|
|
2690 // of 5 runs - Sep 2005).
|
|
2691 //
|
|
2692 // The following code actually changes the niceness of kernel-thread/LWP. It
|
|
2693 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
|
|
2694 // not the entire user process, and user level threads are 1:1 mapped to kernel
|
|
2695 // threads. It has always been the case, but could change in the future. For
|
|
2696 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
|
|
2697 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
|
|
2698
|
|
2699 int os::java_to_os_priority[MaxPriority + 1] = {
|
|
2700 19, // 0 Entry should never be used
|
|
2701
|
|
2702 4, // 1 MinPriority
|
|
2703 3, // 2
|
|
2704 2, // 3
|
|
2705
|
|
2706 1, // 4
|
|
2707 0, // 5 NormPriority
|
|
2708 -1, // 6
|
|
2709
|
|
2710 -2, // 7
|
|
2711 -3, // 8
|
|
2712 -4, // 9 NearMaxPriority
|
|
2713
|
|
2714 -5 // 10 MaxPriority
|
|
2715 };
|
|
2716
|
|
2717 static int prio_init() {
|
|
2718 if (ThreadPriorityPolicy == 1) {
|
|
2719 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
|
|
2720 // if effective uid is not root. Perhaps, a more elegant way of doing
|
|
2721 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
|
|
2722 if (geteuid() != 0) {
|
|
2723 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
|
|
2724 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux");
|
|
2725 }
|
|
2726 ThreadPriorityPolicy = 0;
|
|
2727 }
|
|
2728 }
|
|
2729 return 0;
|
|
2730 }
|
|
2731
|
|
2732 OSReturn os::set_native_priority(Thread* thread, int newpri) {
|
|
2733 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
|
|
2734
|
|
2735 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
|
|
2736 return (ret == 0) ? OS_OK : OS_ERR;
|
|
2737 }
|
|
2738
|
|
2739 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
|
|
2740 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
|
|
2741 *priority_ptr = java_to_os_priority[NormPriority];
|
|
2742 return OS_OK;
|
|
2743 }
|
|
2744
|
|
2745 errno = 0;
|
|
2746 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
|
|
2747 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
|
|
2748 }
|
|
2749
|
|
2750 // Hint to the underlying OS that a task switch would not be good.
|
|
2751 // Void return because it's a hint and can fail.
|
|
2752 void os::hint_no_preempt() {}
|
|
2753
|
|
2754 ////////////////////////////////////////////////////////////////////////////////
|
|
2755 // suspend/resume support
|
|
2756
|
|
2757 // the low-level signal-based suspend/resume support is a remnant from the
|
|
2758 // old VM-suspension that used to be for java-suspension, safepoints etc,
|
|
2759 // within hotspot. Now there is a single use-case for this:
|
|
2760 // - calling get_thread_pc() on the VMThread by the flat-profiler task
|
|
2761 // that runs in the watcher thread.
|
|
2762 // The remaining code is greatly simplified from the more general suspension
|
|
2763 // code that used to be used.
|
|
2764 //
|
|
2765 // The protocol is quite simple:
|
|
2766 // - suspend:
|
|
2767 // - sends a signal to the target thread
|
|
2768 // - polls the suspend state of the osthread using a yield loop
|
|
2769 // - target thread signal handler (SR_handler) sets suspend state
|
|
2770 // and blocks in sigsuspend until continued
|
|
2771 // - resume:
|
|
2772 // - sets target osthread state to continue
|
|
2773 // - sends signal to end the sigsuspend loop in the SR_handler
|
|
2774 //
|
|
2775 // Note that the SR_lock plays no role in this suspend/resume protocol.
|
|
2776 //
|
|
2777
|
|
2778 static void resume_clear_context(OSThread *osthread) {
|
|
2779 osthread->set_ucontext(NULL);
|
|
2780 osthread->set_siginfo(NULL);
|
|
2781
|
|
2782 // notify the suspend action is completed, we have now resumed
|
|
2783 osthread->sr.clear_suspended();
|
|
2784 }
|
|
2785
|
|
2786 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
|
|
2787 osthread->set_ucontext(context);
|
|
2788 osthread->set_siginfo(siginfo);
|
|
2789 }
|
|
2790
|
|
2791 //
|
|
2792 // Handler function invoked when a thread's execution is suspended or
|
|
2793 // resumed. We have to be careful that only async-safe functions are
|
|
2794 // called here (Note: most pthread functions are not async safe and
|
|
2795 // should be avoided.)
|
|
2796 //
|
|
2797 // Note: sigwait() is a more natural fit than sigsuspend() from an
|
|
2798 // interface point of view, but sigwait() prevents the signal hander
|
|
2799 // from being run. libpthread would get very confused by not having
|
|
2800 // its signal handlers run and prevents sigwait()'s use with the
|
|
2801 // mutex granting granting signal.
|
|
2802 //
|
|
2803 // Currently only ever called on the VMThread
|
|
2804 //
|
|
2805 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
|
|
2806 // Save and restore errno to avoid confusing native code with EINTR
|
|
2807 // after sigsuspend.
|
|
2808 int old_errno = errno;
|
|
2809
|
|
2810 Thread* thread = Thread::current();
|
|
2811 OSThread* osthread = thread->osthread();
|
|
2812 assert(thread->is_VM_thread(), "Must be VMThread");
|
|
2813 // read current suspend action
|
|
2814 int action = osthread->sr.suspend_action();
|
|
2815 if (action == SR_SUSPEND) {
|
|
2816 suspend_save_context(osthread, siginfo, context);
|
|
2817
|
|
2818 // Notify the suspend action is about to be completed. do_suspend()
|
|
2819 // waits until SR_SUSPENDED is set and then returns. We will wait
|
|
2820 // here for a resume signal and that completes the suspend-other
|
|
2821 // action. do_suspend/do_resume is always called as a pair from
|
|
2822 // the same thread - so there are no races
|
|
2823
|
|
2824 // notify the caller
|
|
2825 osthread->sr.set_suspended();
|
|
2826
|
|
2827 sigset_t suspend_set; // signals for sigsuspend()
|
|
2828
|
|
2829 // get current set of blocked signals and unblock resume signal
|
|
2830 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
|
|
2831 sigdelset(&suspend_set, SR_signum);
|
|
2832
|
|
2833 // wait here until we are resumed
|
|
2834 do {
|
|
2835 sigsuspend(&suspend_set);
|
|
2836 // ignore all returns until we get a resume signal
|
|
2837 } while (osthread->sr.suspend_action() != SR_CONTINUE);
|
|
2838
|
|
2839 resume_clear_context(osthread);
|
|
2840
|
|
2841 } else {
|
|
2842 assert(action == SR_CONTINUE, "unexpected sr action");
|
|
2843 // nothing special to do - just leave the handler
|
|
2844 }
|
|
2845
|
|
2846 errno = old_errno;
|
|
2847 }
|
|
2848
|
|
2849
|
|
2850 static int SR_initialize() {
|
|
2851 struct sigaction act;
|
|
2852 char *s;
|
|
2853 /* Get signal number to use for suspend/resume */
|
|
2854 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
|
|
2855 int sig = ::strtol(s, 0, 10);
|
|
2856 if (sig > 0 || sig < _NSIG) {
|
|
2857 SR_signum = sig;
|
|
2858 }
|
|
2859 }
|
|
2860
|
|
2861 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
|
|
2862 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
|
|
2863
|
|
2864 sigemptyset(&SR_sigset);
|
|
2865 sigaddset(&SR_sigset, SR_signum);
|
|
2866
|
|
2867 /* Set up signal handler for suspend/resume */
|
|
2868 act.sa_flags = SA_RESTART|SA_SIGINFO;
|
|
2869 act.sa_handler = (void (*)(int)) SR_handler;
|
|
2870
|
|
2871 // SR_signum is blocked by default.
|
|
2872 // 4528190 - We also need to block pthread restart signal (32 on all
|
|
2873 // supported Linux platforms). Note that LinuxThreads need to block
|
|
2874 // this signal for all threads to work properly. So we don't have
|
|
2875 // to use hard-coded signal number when setting up the mask.
|
|
2876 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
|
|
2877
|
|
2878 if (sigaction(SR_signum, &act, 0) == -1) {
|
|
2879 return -1;
|
|
2880 }
|
|
2881
|
|
2882 // Save signal flag
|
|
2883 os::Linux::set_our_sigflags(SR_signum, act.sa_flags);
|
|
2884 return 0;
|
|
2885 }
|
|
2886
|
|
2887 static int SR_finalize() {
|
|
2888 return 0;
|
|
2889 }
|
|
2890
|
|
2891
|
|
2892 // returns true on success and false on error - really an error is fatal
|
|
2893 // but this seems the normal response to library errors
|
|
2894 static bool do_suspend(OSThread* osthread) {
|
|
2895 // mark as suspended and send signal
|
|
2896 osthread->sr.set_suspend_action(SR_SUSPEND);
|
|
2897 int status = pthread_kill(osthread->pthread_id(), SR_signum);
|
|
2898 assert_status(status == 0, status, "pthread_kill");
|
|
2899
|
|
2900 // check status and wait until notified of suspension
|
|
2901 if (status == 0) {
|
|
2902 for (int i = 0; !osthread->sr.is_suspended(); i++) {
|
|
2903 os::yield_all(i);
|
|
2904 }
|
|
2905 osthread->sr.set_suspend_action(SR_NONE);
|
|
2906 return true;
|
|
2907 }
|
|
2908 else {
|
|
2909 osthread->sr.set_suspend_action(SR_NONE);
|
|
2910 return false;
|
|
2911 }
|
|
2912 }
|
|
2913
|
|
2914 static void do_resume(OSThread* osthread) {
|
|
2915 assert(osthread->sr.is_suspended(), "thread should be suspended");
|
|
2916 osthread->sr.set_suspend_action(SR_CONTINUE);
|
|
2917
|
|
2918 int status = pthread_kill(osthread->pthread_id(), SR_signum);
|
|
2919 assert_status(status == 0, status, "pthread_kill");
|
|
2920 // check status and wait unit notified of resumption
|
|
2921 if (status == 0) {
|
|
2922 for (int i = 0; osthread->sr.is_suspended(); i++) {
|
|
2923 os::yield_all(i);
|
|
2924 }
|
|
2925 }
|
|
2926 osthread->sr.set_suspend_action(SR_NONE);
|
|
2927 }
|
|
2928
|
|
2929 ////////////////////////////////////////////////////////////////////////////////
|
|
2930 // interrupt support
|
|
2931
|
|
2932 void os::interrupt(Thread* thread) {
|
|
2933 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
|
|
2934 "possibility of dangling Thread pointer");
|
|
2935
|
|
2936 OSThread* osthread = thread->osthread();
|
|
2937
|
|
2938 if (!osthread->interrupted()) {
|
|
2939 osthread->set_interrupted(true);
|
|
2940 // More than one thread can get here with the same value of osthread,
|
|
2941 // resulting in multiple notifications. We do, however, want the store
|
|
2942 // to interrupted() to be visible to other threads before we execute unpark().
|
|
2943 OrderAccess::fence();
|
|
2944 ParkEvent * const slp = thread->_SleepEvent ;
|
|
2945 if (slp != NULL) slp->unpark() ;
|
|
2946 }
|
|
2947
|
|
2948 // For JSR166. Unpark even if interrupt status already was set
|
|
2949 if (thread->is_Java_thread())
|
|
2950 ((JavaThread*)thread)->parker()->unpark();
|
|
2951
|
|
2952 ParkEvent * ev = thread->_ParkEvent ;
|
|
2953 if (ev != NULL) ev->unpark() ;
|
|
2954
|
|
2955 }
|
|
2956
|
|
2957 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
|
|
2958 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
|
|
2959 "possibility of dangling Thread pointer");
|
|
2960
|
|
2961 OSThread* osthread = thread->osthread();
|
|
2962
|
|
2963 bool interrupted = osthread->interrupted();
|
|
2964
|
|
2965 if (interrupted && clear_interrupted) {
|
|
2966 osthread->set_interrupted(false);
|
|
2967 // consider thread->_SleepEvent->reset() ... optional optimization
|
|
2968 }
|
|
2969
|
|
2970 return interrupted;
|
|
2971 }
|
|
2972
|
|
2973 ///////////////////////////////////////////////////////////////////////////////////
|
|
2974 // signal handling (except suspend/resume)
|
|
2975
|
|
2976 // This routine may be used by user applications as a "hook" to catch signals.
|
|
2977 // The user-defined signal handler must pass unrecognized signals to this
|
|
2978 // routine, and if it returns true (non-zero), then the signal handler must
|
|
2979 // return immediately. If the flag "abort_if_unrecognized" is true, then this
|
|
2980 // routine will never retun false (zero), but instead will execute a VM panic
|
|
2981 // routine kill the process.
|
|
2982 //
|
|
2983 // If this routine returns false, it is OK to call it again. This allows
|
|
2984 // the user-defined signal handler to perform checks either before or after
|
|
2985 // the VM performs its own checks. Naturally, the user code would be making
|
|
2986 // a serious error if it tried to handle an exception (such as a null check
|
|
2987 // or breakpoint) that the VM was generating for its own correct operation.
|
|
2988 //
|
|
2989 // This routine may recognize any of the following kinds of signals:
|
|
2990 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
|
|
2991 // It should be consulted by handlers for any of those signals.
|
|
2992 //
|
|
2993 // The caller of this routine must pass in the three arguments supplied
|
|
2994 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
|
|
2995 // field of the structure passed to sigaction(). This routine assumes that
|
|
2996 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
|
|
2997 //
|
|
2998 // Note that the VM will print warnings if it detects conflicting signal
|
|
2999 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
|
|
3000 //
|
|
3001 extern "C" int
|
|
3002 JVM_handle_linux_signal(int signo, siginfo_t* siginfo,
|
|
3003 void* ucontext, int abort_if_unrecognized);
|
|
3004
|
|
3005 void signalHandler(int sig, siginfo_t* info, void* uc) {
|
|
3006 assert(info != NULL && uc != NULL, "it must be old kernel");
|
|
3007 JVM_handle_linux_signal(sig, info, uc, true);
|
|
3008 }
|
|
3009
|
|
3010
|
|
3011 // This boolean allows users to forward their own non-matching signals
|
|
3012 // to JVM_handle_linux_signal, harmlessly.
|
|
3013 bool os::Linux::signal_handlers_are_installed = false;
|
|
3014
|
|
3015 // For signal-chaining
|
|
3016 struct sigaction os::Linux::sigact[MAXSIGNUM];
|
|
3017 unsigned int os::Linux::sigs = 0;
|
|
3018 bool os::Linux::libjsig_is_loaded = false;
|
|
3019 typedef struct sigaction *(*get_signal_t)(int);
|
|
3020 get_signal_t os::Linux::get_signal_action = NULL;
|
|
3021
|
|
3022 struct sigaction* os::Linux::get_chained_signal_action(int sig) {
|
|
3023 struct sigaction *actp = NULL;
|
|
3024
|
|
3025 if (libjsig_is_loaded) {
|
|
3026 // Retrieve the old signal handler from libjsig
|
|
3027 actp = (*get_signal_action)(sig);
|
|
3028 }
|
|
3029 if (actp == NULL) {
|
|
3030 // Retrieve the preinstalled signal handler from jvm
|
|
3031 actp = get_preinstalled_handler(sig);
|
|
3032 }
|
|
3033
|
|
3034 return actp;
|
|
3035 }
|
|
3036
|
|
3037 static bool call_chained_handler(struct sigaction *actp, int sig,
|
|
3038 siginfo_t *siginfo, void *context) {
|
|
3039 // Call the old signal handler
|
|
3040 if (actp->sa_handler == SIG_DFL) {
|
|
3041 // It's more reasonable to let jvm treat it as an unexpected exception
|
|
3042 // instead of taking the default action.
|
|
3043 return false;
|
|
3044 } else if (actp->sa_handler != SIG_IGN) {
|
|
3045 if ((actp->sa_flags & SA_NODEFER) == 0) {
|
|
3046 // automaticlly block the signal
|
|
3047 sigaddset(&(actp->sa_mask), sig);
|
|
3048 }
|
|
3049
|
|
3050 sa_handler_t hand;
|
|
3051 sa_sigaction_t sa;
|
|
3052 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
|
|
3053 // retrieve the chained handler
|
|
3054 if (siginfo_flag_set) {
|
|
3055 sa = actp->sa_sigaction;
|
|
3056 } else {
|
|
3057 hand = actp->sa_handler;
|
|
3058 }
|
|
3059
|
|
3060 if ((actp->sa_flags & SA_RESETHAND) != 0) {
|
|
3061 actp->sa_handler = SIG_DFL;
|
|
3062 }
|
|
3063
|
|
3064 // try to honor the signal mask
|
|
3065 sigset_t oset;
|
|
3066 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
|
|
3067
|
|
3068 // call into the chained handler
|
|
3069 if (siginfo_flag_set) {
|
|
3070 (*sa)(sig, siginfo, context);
|
|
3071 } else {
|
|
3072 (*hand)(sig);
|
|
3073 }
|
|
3074
|
|
3075 // restore the signal mask
|
|
3076 pthread_sigmask(SIG_SETMASK, &oset, 0);
|
|
3077 }
|
|
3078 // Tell jvm's signal handler the signal is taken care of.
|
|
3079 return true;
|
|
3080 }
|
|
3081
|
|
3082 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) {
|
|
3083 bool chained = false;
|
|
3084 // signal-chaining
|
|
3085 if (UseSignalChaining) {
|
|
3086 struct sigaction *actp = get_chained_signal_action(sig);
|
|
3087 if (actp != NULL) {
|
|
3088 chained = call_chained_handler(actp, sig, siginfo, context);
|
|
3089 }
|
|
3090 }
|
|
3091 return chained;
|
|
3092 }
|
|
3093
|
|
3094 struct sigaction* os::Linux::get_preinstalled_handler(int sig) {
|
|
3095 if ((( (unsigned int)1 << sig ) & sigs) != 0) {
|
|
3096 return &sigact[sig];
|
|
3097 }
|
|
3098 return NULL;
|
|
3099 }
|
|
3100
|
|
3101 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
|
|
3102 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
|
|
3103 sigact[sig] = oldAct;
|
|
3104 sigs |= (unsigned int)1 << sig;
|
|
3105 }
|
|
3106
|
|
3107 // for diagnostic
|
|
3108 int os::Linux::sigflags[MAXSIGNUM];
|
|
3109
|
|
3110 int os::Linux::get_our_sigflags(int sig) {
|
|
3111 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
|
|
3112 return sigflags[sig];
|
|
3113 }
|
|
3114
|
|
3115 void os::Linux::set_our_sigflags(int sig, int flags) {
|
|
3116 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
|
|
3117 sigflags[sig] = flags;
|
|
3118 }
|
|
3119
|
|
3120 void os::Linux::set_signal_handler(int sig, bool set_installed) {
|
|
3121 // Check for overwrite.
|
|
3122 struct sigaction oldAct;
|
|
3123 sigaction(sig, (struct sigaction*)NULL, &oldAct);
|
|
3124
|
|
3125 void* oldhand = oldAct.sa_sigaction
|
|
3126 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
|
|
3127 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
|
|
3128 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
|
|
3129 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
|
|
3130 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
|
|
3131 if (AllowUserSignalHandlers || !set_installed) {
|
|
3132 // Do not overwrite; user takes responsibility to forward to us.
|
|
3133 return;
|
|
3134 } else if (UseSignalChaining) {
|
|
3135 // save the old handler in jvm
|
|
3136 save_preinstalled_handler(sig, oldAct);
|
|
3137 // libjsig also interposes the sigaction() call below and saves the
|
|
3138 // old sigaction on it own.
|
|
3139 } else {
|
|
3140 fatal2("Encountered unexpected pre-existing sigaction handler %#lx for signal %d.", (long)oldhand, sig);
|
|
3141 }
|
|
3142 }
|
|
3143
|
|
3144 struct sigaction sigAct;
|
|
3145 sigfillset(&(sigAct.sa_mask));
|
|
3146 sigAct.sa_handler = SIG_DFL;
|
|
3147 if (!set_installed) {
|
|
3148 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
|
|
3149 } else {
|
|
3150 sigAct.sa_sigaction = signalHandler;
|
|
3151 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
|
|
3152 }
|
|
3153 // Save flags, which are set by ours
|
|
3154 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
|
|
3155 sigflags[sig] = sigAct.sa_flags;
|
|
3156
|
|
3157 int ret = sigaction(sig, &sigAct, &oldAct);
|
|
3158 assert(ret == 0, "check");
|
|
3159
|
|
3160 void* oldhand2 = oldAct.sa_sigaction
|
|
3161 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
|
|
3162 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
|
|
3163 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
|
|
3164 }
|
|
3165
|
|
3166 // install signal handlers for signals that HotSpot needs to
|
|
3167 // handle in order to support Java-level exception handling.
|
|
3168
|
|
3169 void os::Linux::install_signal_handlers() {
|
|
3170 if (!signal_handlers_are_installed) {
|
|
3171 signal_handlers_are_installed = true;
|
|
3172
|
|
3173 // signal-chaining
|
|
3174 typedef void (*signal_setting_t)();
|
|
3175 signal_setting_t begin_signal_setting = NULL;
|
|
3176 signal_setting_t end_signal_setting = NULL;
|
|
3177 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
|
|
3178 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
|
|
3179 if (begin_signal_setting != NULL) {
|
|
3180 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
|
|
3181 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
|
|
3182 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
|
|
3183 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
|
|
3184 libjsig_is_loaded = true;
|
|
3185 assert(UseSignalChaining, "should enable signal-chaining");
|
|
3186 }
|
|
3187 if (libjsig_is_loaded) {
|
|
3188 // Tell libjsig jvm is setting signal handlers
|
|
3189 (*begin_signal_setting)();
|
|
3190 }
|
|
3191
|
|
3192 set_signal_handler(SIGSEGV, true);
|
|
3193 set_signal_handler(SIGPIPE, true);
|
|
3194 set_signal_handler(SIGBUS, true);
|
|
3195 set_signal_handler(SIGILL, true);
|
|
3196 set_signal_handler(SIGFPE, true);
|
|
3197 set_signal_handler(SIGXFSZ, true);
|
|
3198
|
|
3199 if (libjsig_is_loaded) {
|
|
3200 // Tell libjsig jvm finishes setting signal handlers
|
|
3201 (*end_signal_setting)();
|
|
3202 }
|
|
3203
|
|
3204 // We don't activate signal checker if libjsig is in place, we trust ourselves
|
|
3205 // and if UserSignalHandler is installed all bets are off
|
|
3206 if (CheckJNICalls) {
|
|
3207 if (libjsig_is_loaded) {
|
|
3208 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
|
|
3209 check_signals = false;
|
|
3210 }
|
|
3211 if (AllowUserSignalHandlers) {
|
|
3212 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
|
|
3213 check_signals = false;
|
|
3214 }
|
|
3215 }
|
|
3216 }
|
|
3217 }
|
|
3218
|
|
3219 // This is the fastest way to get thread cpu time on Linux.
|
|
3220 // Returns cpu time (user+sys) for any thread, not only for current.
|
|
3221 // POSIX compliant clocks are implemented in the kernels 2.6.16+.
|
|
3222 // It might work on 2.6.10+ with a special kernel/glibc patch.
|
|
3223 // For reference, please, see IEEE Std 1003.1-2004:
|
|
3224 // http://www.unix.org/single_unix_specification
|
|
3225
|
|
3226 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) {
|
|
3227 struct timespec tp;
|
|
3228 int rc = os::Linux::clock_gettime(clockid, &tp);
|
|
3229 assert(rc == 0, "clock_gettime is expected to return 0 code");
|
|
3230
|
|
3231 return (tp.tv_sec * SEC_IN_NANOSECS) + tp.tv_nsec;
|
|
3232 }
|
|
3233
|
|
3234 /////
|
|
3235 // glibc on Linux platform uses non-documented flag
|
|
3236 // to indicate, that some special sort of signal
|
|
3237 // trampoline is used.
|
|
3238 // We will never set this flag, and we should
|
|
3239 // ignore this flag in our diagnostic
|
|
3240 #ifdef SIGNIFICANT_SIGNAL_MASK
|
|
3241 #undef SIGNIFICANT_SIGNAL_MASK
|
|
3242 #endif
|
|
3243 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
|
|
3244
|
|
3245 static const char* get_signal_handler_name(address handler,
|
|
3246 char* buf, int buflen) {
|
|
3247 int offset;
|
|
3248 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
|
|
3249 if (found) {
|
|
3250 // skip directory names
|
|
3251 const char *p1, *p2;
|
|
3252 p1 = buf;
|
|
3253 size_t len = strlen(os::file_separator());
|
|
3254 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
|
|
3255 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
|
|
3256 } else {
|
|
3257 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
|
|
3258 }
|
|
3259 return buf;
|
|
3260 }
|
|
3261
|
|
3262 static void print_signal_handler(outputStream* st, int sig,
|
|
3263 char* buf, size_t buflen) {
|
|
3264 struct sigaction sa;
|
|
3265
|
|
3266 sigaction(sig, NULL, &sa);
|
|
3267
|
|
3268 // See comment for SIGNIFICANT_SIGNAL_MASK define
|
|
3269 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
|
|
3270
|
|
3271 st->print("%s: ", os::exception_name(sig, buf, buflen));
|
|
3272
|
|
3273 address handler = (sa.sa_flags & SA_SIGINFO)
|
|
3274 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
|
|
3275 : CAST_FROM_FN_PTR(address, sa.sa_handler);
|
|
3276
|
|
3277 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
|
|
3278 st->print("SIG_DFL");
|
|
3279 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
|
|
3280 st->print("SIG_IGN");
|
|
3281 } else {
|
|
3282 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
|
|
3283 }
|
|
3284
|
|
3285 st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
|
|
3286
|
|
3287 address rh = VMError::get_resetted_sighandler(sig);
|
|
3288 // May be, handler was resetted by VMError?
|
|
3289 if(rh != NULL) {
|
|
3290 handler = rh;
|
|
3291 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
|
|
3292 }
|
|
3293
|
|
3294 st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags);
|
|
3295
|
|
3296 // Check: is it our handler?
|
|
3297 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
|
|
3298 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
|
|
3299 // It is our signal handler
|
|
3300 // check for flags, reset system-used one!
|
|
3301 if((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) {
|
|
3302 st->print(
|
|
3303 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
|
|
3304 os::Linux::get_our_sigflags(sig));
|
|
3305 }
|
|
3306 }
|
|
3307 st->cr();
|
|
3308 }
|
|
3309
|
|
3310
|
|
3311 #define DO_SIGNAL_CHECK(sig) \
|
|
3312 if (!sigismember(&check_signal_done, sig)) \
|
|
3313 os::Linux::check_signal_handler(sig)
|
|
3314
|
|
3315 // This method is a periodic task to check for misbehaving JNI applications
|
|
3316 // under CheckJNI, we can add any periodic checks here
|
|
3317
|
|
3318 void os::run_periodic_checks() {
|
|
3319
|
|
3320 if (check_signals == false) return;
|
|
3321
|
|
3322 // SEGV and BUS if overridden could potentially prevent
|
|
3323 // generation of hs*.log in the event of a crash, debugging
|
|
3324 // such a case can be very challenging, so we absolutely
|
|
3325 // check the following for a good measure:
|
|
3326 DO_SIGNAL_CHECK(SIGSEGV);
|
|
3327 DO_SIGNAL_CHECK(SIGILL);
|
|
3328 DO_SIGNAL_CHECK(SIGFPE);
|
|
3329 DO_SIGNAL_CHECK(SIGBUS);
|
|
3330 DO_SIGNAL_CHECK(SIGPIPE);
|
|
3331 DO_SIGNAL_CHECK(SIGXFSZ);
|
|
3332
|
|
3333
|
|
3334 // ReduceSignalUsage allows the user to override these handlers
|
|
3335 // see comments at the very top and jvm_solaris.h
|
|
3336 if (!ReduceSignalUsage) {
|
|
3337 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
|
|
3338 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
|
|
3339 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
|
|
3340 DO_SIGNAL_CHECK(BREAK_SIGNAL);
|
|
3341 }
|
|
3342
|
|
3343 DO_SIGNAL_CHECK(SR_signum);
|
|
3344 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
|
|
3345 }
|
|
3346
|
|
3347 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
|
|
3348
|
|
3349 static os_sigaction_t os_sigaction = NULL;
|
|
3350
|
|
3351 void os::Linux::check_signal_handler(int sig) {
|
|
3352 char buf[O_BUFLEN];
|
|
3353 address jvmHandler = NULL;
|
|
3354
|
|
3355
|
|
3356 struct sigaction act;
|
|
3357 if (os_sigaction == NULL) {
|
|
3358 // only trust the default sigaction, in case it has been interposed
|
|
3359 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
|
|
3360 if (os_sigaction == NULL) return;
|
|
3361 }
|
|
3362
|
|
3363 os_sigaction(sig, (struct sigaction*)NULL, &act);
|
|
3364
|
|
3365
|
|
3366 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
|
|
3367
|
|
3368 address thisHandler = (act.sa_flags & SA_SIGINFO)
|
|
3369 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
|
|
3370 : CAST_FROM_FN_PTR(address, act.sa_handler) ;
|
|
3371
|
|
3372
|
|
3373 switch(sig) {
|
|
3374 case SIGSEGV:
|
|
3375 case SIGBUS:
|
|
3376 case SIGFPE:
|
|
3377 case SIGPIPE:
|
|
3378 case SIGILL:
|
|
3379 case SIGXFSZ:
|
|
3380 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
|
|
3381 break;
|
|
3382
|
|
3383 case SHUTDOWN1_SIGNAL:
|
|
3384 case SHUTDOWN2_SIGNAL:
|
|
3385 case SHUTDOWN3_SIGNAL:
|
|
3386 case BREAK_SIGNAL:
|
|
3387 jvmHandler = (address)user_handler();
|
|
3388 break;
|
|
3389
|
|
3390 case INTERRUPT_SIGNAL:
|
|
3391 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
|
|
3392 break;
|
|
3393
|
|
3394 default:
|
|
3395 if (sig == SR_signum) {
|
|
3396 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
|
|
3397 } else {
|
|
3398 return;
|
|
3399 }
|
|
3400 break;
|
|
3401 }
|
|
3402
|
|
3403 if (thisHandler != jvmHandler) {
|
|
3404 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
|
|
3405 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
|
|
3406 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
|
|
3407 // No need to check this sig any longer
|
|
3408 sigaddset(&check_signal_done, sig);
|
|
3409 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) {
|
|
3410 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
|
|
3411 tty->print("expected:" PTR32_FORMAT, os::Linux::get_our_sigflags(sig));
|
|
3412 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags);
|
|
3413 // No need to check this sig any longer
|
|
3414 sigaddset(&check_signal_done, sig);
|
|
3415 }
|
|
3416
|
|
3417 // Dump all the signal
|
|
3418 if (sigismember(&check_signal_done, sig)) {
|
|
3419 print_signal_handlers(tty, buf, O_BUFLEN);
|
|
3420 }
|
|
3421 }
|
|
3422
|
|
3423 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
|
|
3424
|
|
3425 extern bool signal_name(int signo, char* buf, size_t len);
|
|
3426
|
|
3427 const char* os::exception_name(int exception_code, char* buf, size_t size) {
|
|
3428 if (0 < exception_code && exception_code <= SIGRTMAX) {
|
|
3429 // signal
|
|
3430 if (!signal_name(exception_code, buf, size)) {
|
|
3431 jio_snprintf(buf, size, "SIG%d", exception_code);
|
|
3432 }
|
|
3433 return buf;
|
|
3434 } else {
|
|
3435 return NULL;
|
|
3436 }
|
|
3437 }
|
|
3438
|
|
3439 // this is called _before_ the most of global arguments have been parsed
|
|
3440 void os::init(void) {
|
|
3441 char dummy; /* used to get a guess on initial stack address */
|
|
3442 // first_hrtime = gethrtime();
|
|
3443
|
|
3444 // With LinuxThreads the JavaMain thread pid (primordial thread)
|
|
3445 // is different than the pid of the java launcher thread.
|
|
3446 // So, on Linux, the launcher thread pid is passed to the VM
|
|
3447 // via the sun.java.launcher.pid property.
|
|
3448 // Use this property instead of getpid() if it was correctly passed.
|
|
3449 // See bug 6351349.
|
|
3450 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
|
|
3451
|
|
3452 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
|
|
3453
|
|
3454 clock_tics_per_sec = sysconf(_SC_CLK_TCK);
|
|
3455
|
|
3456 init_random(1234567);
|
|
3457
|
|
3458 ThreadCritical::initialize();
|
|
3459
|
|
3460 Linux::set_page_size(sysconf(_SC_PAGESIZE));
|
|
3461 if (Linux::page_size() == -1) {
|
|
3462 fatal1("os_linux.cpp: os::init: sysconf failed (%s)", strerror(errno));
|
|
3463 }
|
|
3464 init_page_sizes((size_t) Linux::page_size());
|
|
3465
|
|
3466 Linux::initialize_system_info();
|
|
3467
|
|
3468 // main_thread points to the aboriginal thread
|
|
3469 Linux::_main_thread = pthread_self();
|
|
3470
|
|
3471 Linux::clock_init();
|
|
3472 initial_time_count = os::elapsed_counter();
|
|
3473 }
|
|
3474
|
|
3475 // To install functions for atexit system call
|
|
3476 extern "C" {
|
|
3477 static void perfMemory_exit_helper() {
|
|
3478 perfMemory_exit();
|
|
3479 }
|
|
3480 }
|
|
3481
|
|
3482 // this is called _after_ the global arguments have been parsed
|
|
3483 jint os::init_2(void)
|
|
3484 {
|
|
3485 Linux::fast_thread_clock_init();
|
|
3486
|
|
3487 // Allocate a single page and mark it as readable for safepoint polling
|
|
3488 address polling_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
|
|
3489 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
|
|
3490
|
|
3491 os::set_polling_page( polling_page );
|
|
3492
|
|
3493 #ifndef PRODUCT
|
|
3494 if(Verbose && PrintMiscellaneous)
|
|
3495 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
|
|
3496 #endif
|
|
3497
|
|
3498 if (!UseMembar) {
|
|
3499 address mem_serialize_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
|
|
3500 guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page");
|
|
3501 os::set_memory_serialize_page( mem_serialize_page );
|
|
3502
|
|
3503 #ifndef PRODUCT
|
|
3504 if(Verbose && PrintMiscellaneous)
|
|
3505 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
|
|
3506 #endif
|
|
3507 }
|
|
3508
|
|
3509 FLAG_SET_DEFAULT(UseLargePages, os::large_page_init());
|
|
3510
|
|
3511 // initialize suspend/resume support - must do this before signal_sets_init()
|
|
3512 if (SR_initialize() != 0) {
|
|
3513 perror("SR_initialize failed");
|
|
3514 return JNI_ERR;
|
|
3515 }
|
|
3516
|
|
3517 Linux::signal_sets_init();
|
|
3518 Linux::install_signal_handlers();
|
|
3519
|
|
3520 size_t threadStackSizeInBytes = ThreadStackSize * K;
|
|
3521 if (threadStackSizeInBytes != 0 &&
|
|
3522 threadStackSizeInBytes < Linux::min_stack_allowed) {
|
|
3523 tty->print_cr("\nThe stack size specified is too small, "
|
|
3524 "Specify at least %dk",
|
|
3525 Linux::min_stack_allowed / K);
|
|
3526 return JNI_ERR;
|
|
3527 }
|
|
3528
|
|
3529 // Make the stack size a multiple of the page size so that
|
|
3530 // the yellow/red zones can be guarded.
|
|
3531 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
|
|
3532 vm_page_size()));
|
|
3533
|
|
3534 Linux::capture_initial_stack(JavaThread::stack_size_at_create());
|
|
3535
|
|
3536 Linux::libpthread_init();
|
|
3537 if (PrintMiscellaneous && (Verbose || WizardMode)) {
|
|
3538 tty->print_cr("[HotSpot is running with %s, %s(%s)]\n",
|
|
3539 Linux::glibc_version(), Linux::libpthread_version(),
|
|
3540 Linux::is_floating_stack() ? "floating stack" : "fixed stack");
|
|
3541 }
|
|
3542
|
|
3543 if (MaxFDLimit) {
|
|
3544 // set the number of file descriptors to max. print out error
|
|
3545 // if getrlimit/setrlimit fails but continue regardless.
|
|
3546 struct rlimit nbr_files;
|
|
3547 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
|
|
3548 if (status != 0) {
|
|
3549 if (PrintMiscellaneous && (Verbose || WizardMode))
|
|
3550 perror("os::init_2 getrlimit failed");
|
|
3551 } else {
|
|
3552 nbr_files.rlim_cur = nbr_files.rlim_max;
|
|
3553 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
|
|
3554 if (status != 0) {
|
|
3555 if (PrintMiscellaneous && (Verbose || WizardMode))
|
|
3556 perror("os::init_2 setrlimit failed");
|
|
3557 }
|
|
3558 }
|
|
3559 }
|
|
3560
|
|
3561 // Initialize lock used to serialize thread creation (see os::create_thread)
|
|
3562 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false));
|
|
3563
|
|
3564 // Initialize HPI.
|
|
3565 jint hpi_result = hpi::initialize();
|
|
3566 if (hpi_result != JNI_OK) {
|
|
3567 tty->print_cr("There was an error trying to initialize the HPI library.");
|
|
3568 return hpi_result;
|
|
3569 }
|
|
3570
|
|
3571 // at-exit methods are called in the reverse order of their registration.
|
|
3572 // atexit functions are called on return from main or as a result of a
|
|
3573 // call to exit(3C). There can be only 32 of these functions registered
|
|
3574 // and atexit() does not set errno.
|
|
3575
|
|
3576 if (PerfAllowAtExitRegistration) {
|
|
3577 // only register atexit functions if PerfAllowAtExitRegistration is set.
|
|
3578 // atexit functions can be delayed until process exit time, which
|
|
3579 // can be problematic for embedded VM situations. Embedded VMs should
|
|
3580 // call DestroyJavaVM() to assure that VM resources are released.
|
|
3581
|
|
3582 // note: perfMemory_exit_helper atexit function may be removed in
|
|
3583 // the future if the appropriate cleanup code can be added to the
|
|
3584 // VM_Exit VMOperation's doit method.
|
|
3585 if (atexit(perfMemory_exit_helper) != 0) {
|
|
3586 warning("os::init2 atexit(perfMemory_exit_helper) failed");
|
|
3587 }
|
|
3588 }
|
|
3589
|
|
3590 // initialize thread priority policy
|
|
3591 prio_init();
|
|
3592
|
|
3593 return JNI_OK;
|
|
3594 }
|
|
3595
|
|
3596 // Mark the polling page as unreadable
|
|
3597 void os::make_polling_page_unreadable(void) {
|
|
3598 if( !guard_memory((char*)_polling_page, Linux::page_size()) )
|
|
3599 fatal("Could not disable polling page");
|
|
3600 };
|
|
3601
|
|
3602 // Mark the polling page as readable
|
|
3603 void os::make_polling_page_readable(void) {
|
|
3604 if( !protect_memory((char *)_polling_page, Linux::page_size()) )
|
|
3605 fatal("Could not enable polling page");
|
|
3606 };
|
|
3607
|
|
3608 int os::active_processor_count() {
|
|
3609 // Linux doesn't yet have a (official) notion of processor sets,
|
|
3610 // so just return the number of online processors.
|
|
3611 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
|
|
3612 assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check");
|
|
3613 return online_cpus;
|
|
3614 }
|
|
3615
|
|
3616 bool os::distribute_processes(uint length, uint* distribution) {
|
|
3617 // Not yet implemented.
|
|
3618 return false;
|
|
3619 }
|
|
3620
|
|
3621 bool os::bind_to_processor(uint processor_id) {
|
|
3622 // Not yet implemented.
|
|
3623 return false;
|
|
3624 }
|
|
3625
|
|
3626 ///
|
|
3627
|
|
3628 // Suspends the target using the signal mechanism and then grabs the PC before
|
|
3629 // resuming the target. Used by the flat-profiler only
|
|
3630 ExtendedPC os::get_thread_pc(Thread* thread) {
|
|
3631 // Make sure that it is called by the watcher for the VMThread
|
|
3632 assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
|
|
3633 assert(thread->is_VM_thread(), "Can only be called for VMThread");
|
|
3634
|
|
3635 ExtendedPC epc;
|
|
3636
|
|
3637 OSThread* osthread = thread->osthread();
|
|
3638 if (do_suspend(osthread)) {
|
|
3639 if (osthread->ucontext() != NULL) {
|
|
3640 epc = os::Linux::ucontext_get_pc(osthread->ucontext());
|
|
3641 } else {
|
|
3642 // NULL context is unexpected, double-check this is the VMThread
|
|
3643 guarantee(thread->is_VM_thread(), "can only be called for VMThread");
|
|
3644 }
|
|
3645 do_resume(osthread);
|
|
3646 }
|
|
3647 // failure means pthread_kill failed for some reason - arguably this is
|
|
3648 // a fatal problem, but such problems are ignored elsewhere
|
|
3649
|
|
3650 return epc;
|
|
3651 }
|
|
3652
|
|
3653 int os::Linux::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
|
|
3654 {
|
|
3655 if (is_NPTL()) {
|
|
3656 return pthread_cond_timedwait(_cond, _mutex, _abstime);
|
|
3657 } else {
|
|
3658 #ifndef IA64
|
|
3659 // 6292965: LinuxThreads pthread_cond_timedwait() resets FPU control
|
|
3660 // word back to default 64bit precision if condvar is signaled. Java
|
|
3661 // wants 53bit precision. Save and restore current value.
|
|
3662 int fpu = get_fpu_control_word();
|
|
3663 #endif // IA64
|
|
3664 int status = pthread_cond_timedwait(_cond, _mutex, _abstime);
|
|
3665 #ifndef IA64
|
|
3666 set_fpu_control_word(fpu);
|
|
3667 #endif // IA64
|
|
3668 return status;
|
|
3669 }
|
|
3670 }
|
|
3671
|
|
3672 ////////////////////////////////////////////////////////////////////////////////
|
|
3673 // debug support
|
|
3674
|
|
3675 #ifndef PRODUCT
|
|
3676 static address same_page(address x, address y) {
|
|
3677 int page_bits = -os::vm_page_size();
|
|
3678 if ((intptr_t(x) & page_bits) == (intptr_t(y) & page_bits))
|
|
3679 return x;
|
|
3680 else if (x > y)
|
|
3681 return (address)(intptr_t(y) | ~page_bits) + 1;
|
|
3682 else
|
|
3683 return (address)(intptr_t(y) & page_bits);
|
|
3684 }
|
|
3685
|
|
3686 bool os::find(address addr) {
|
|
3687 Dl_info dlinfo;
|
|
3688 memset(&dlinfo, 0, sizeof(dlinfo));
|
|
3689 if (dladdr(addr, &dlinfo)) {
|
|
3690 tty->print(PTR_FORMAT ": ", addr);
|
|
3691 if (dlinfo.dli_sname != NULL) {
|
|
3692 tty->print("%s+%#x", dlinfo.dli_sname,
|
|
3693 addr - (intptr_t)dlinfo.dli_saddr);
|
|
3694 } else if (dlinfo.dli_fname) {
|
|
3695 tty->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
|
|
3696 } else {
|
|
3697 tty->print("<absolute address>");
|
|
3698 }
|
|
3699 if (dlinfo.dli_fname) {
|
|
3700 tty->print(" in %s", dlinfo.dli_fname);
|
|
3701 }
|
|
3702 if (dlinfo.dli_fbase) {
|
|
3703 tty->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
|
|
3704 }
|
|
3705 tty->cr();
|
|
3706
|
|
3707 if (Verbose) {
|
|
3708 // decode some bytes around the PC
|
|
3709 address begin = same_page(addr-40, addr);
|
|
3710 address end = same_page(addr+40, addr);
|
|
3711 address lowest = (address) dlinfo.dli_sname;
|
|
3712 if (!lowest) lowest = (address) dlinfo.dli_fbase;
|
|
3713 if (begin < lowest) begin = lowest;
|
|
3714 Dl_info dlinfo2;
|
|
3715 if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr
|
|
3716 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
|
|
3717 end = (address) dlinfo2.dli_saddr;
|
|
3718 Disassembler::decode(begin, end);
|
|
3719 }
|
|
3720 return true;
|
|
3721 }
|
|
3722 return false;
|
|
3723 }
|
|
3724
|
|
3725 #endif
|
|
3726
|
|
3727 ////////////////////////////////////////////////////////////////////////////////
|
|
3728 // misc
|
|
3729
|
|
3730 // This does not do anything on Linux. This is basically a hook for being
|
|
3731 // able to use structured exception handling (thread-local exception filters)
|
|
3732 // on, e.g., Win32.
|
|
3733 void
|
|
3734 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
|
|
3735 JavaCallArguments* args, Thread* thread) {
|
|
3736 f(value, method, args, thread);
|
|
3737 }
|
|
3738
|
|
3739 void os::print_statistics() {
|
|
3740 }
|
|
3741
|
|
3742 int os::message_box(const char* title, const char* message) {
|
|
3743 int i;
|
|
3744 fdStream err(defaultStream::error_fd());
|
|
3745 for (i = 0; i < 78; i++) err.print_raw("=");
|
|
3746 err.cr();
|
|
3747 err.print_raw_cr(title);
|
|
3748 for (i = 0; i < 78; i++) err.print_raw("-");
|
|
3749 err.cr();
|
|
3750 err.print_raw_cr(message);
|
|
3751 for (i = 0; i < 78; i++) err.print_raw("=");
|
|
3752 err.cr();
|
|
3753
|
|
3754 char buf[16];
|
|
3755 // Prevent process from exiting upon "read error" without consuming all CPU
|
|
3756 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
|
|
3757
|
|
3758 return buf[0] == 'y' || buf[0] == 'Y';
|
|
3759 }
|
|
3760
|
|
3761 int os::stat(const char *path, struct stat *sbuf) {
|
|
3762 char pathbuf[MAX_PATH];
|
|
3763 if (strlen(path) > MAX_PATH - 1) {
|
|
3764 errno = ENAMETOOLONG;
|
|
3765 return -1;
|
|
3766 }
|
|
3767 hpi::native_path(strcpy(pathbuf, path));
|
|
3768 return ::stat(pathbuf, sbuf);
|
|
3769 }
|
|
3770
|
|
3771 bool os::check_heap(bool force) {
|
|
3772 return true;
|
|
3773 }
|
|
3774
|
|
3775 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
|
|
3776 return ::vsnprintf(buf, count, format, args);
|
|
3777 }
|
|
3778
|
|
3779 // Is a (classpath) directory empty?
|
|
3780 bool os::dir_is_empty(const char* path) {
|
|
3781 DIR *dir = NULL;
|
|
3782 struct dirent *ptr;
|
|
3783
|
|
3784 dir = opendir(path);
|
|
3785 if (dir == NULL) return true;
|
|
3786
|
|
3787 /* Scan the directory */
|
|
3788 bool result = true;
|
|
3789 char buf[sizeof(struct dirent) + MAX_PATH];
|
|
3790 while (result && (ptr = ::readdir(dir)) != NULL) {
|
|
3791 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
|
|
3792 result = false;
|
|
3793 }
|
|
3794 }
|
|
3795 closedir(dir);
|
|
3796 return result;
|
|
3797 }
|
|
3798
|
|
3799 // create binary file, rewriting existing file if required
|
|
3800 int os::create_binary_file(const char* path, bool rewrite_existing) {
|
|
3801 int oflags = O_WRONLY | O_CREAT;
|
|
3802 if (!rewrite_existing) {
|
|
3803 oflags |= O_EXCL;
|
|
3804 }
|
|
3805 return ::open64(path, oflags, S_IREAD | S_IWRITE);
|
|
3806 }
|
|
3807
|
|
3808 // return current position of file pointer
|
|
3809 jlong os::current_file_offset(int fd) {
|
|
3810 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR);
|
|
3811 }
|
|
3812
|
|
3813 // move file pointer to the specified offset
|
|
3814 jlong os::seek_to_file_offset(int fd, jlong offset) {
|
|
3815 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET);
|
|
3816 }
|
|
3817
|
|
3818 // Map a block of memory.
|
|
3819 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
|
|
3820 char *addr, size_t bytes, bool read_only,
|
|
3821 bool allow_exec) {
|
|
3822 int prot;
|
|
3823 int flags;
|
|
3824
|
|
3825 if (read_only) {
|
|
3826 prot = PROT_READ;
|
|
3827 flags = MAP_SHARED;
|
|
3828 } else {
|
|
3829 prot = PROT_READ | PROT_WRITE;
|
|
3830 flags = MAP_PRIVATE;
|
|
3831 }
|
|
3832
|
|
3833 if (allow_exec) {
|
|
3834 prot |= PROT_EXEC;
|
|
3835 }
|
|
3836
|
|
3837 if (addr != NULL) {
|
|
3838 flags |= MAP_FIXED;
|
|
3839 }
|
|
3840
|
|
3841 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
|
|
3842 fd, file_offset);
|
|
3843 if (mapped_address == MAP_FAILED) {
|
|
3844 return NULL;
|
|
3845 }
|
|
3846 return mapped_address;
|
|
3847 }
|
|
3848
|
|
3849
|
|
3850 // Remap a block of memory.
|
|
3851 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
|
|
3852 char *addr, size_t bytes, bool read_only,
|
|
3853 bool allow_exec) {
|
|
3854 // same as map_memory() on this OS
|
|
3855 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
|
|
3856 allow_exec);
|
|
3857 }
|
|
3858
|
|
3859
|
|
3860 // Unmap a block of memory.
|
|
3861 bool os::unmap_memory(char* addr, size_t bytes) {
|
|
3862 return munmap(addr, bytes) == 0;
|
|
3863 }
|
|
3864
|
|
3865 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time);
|
|
3866
|
|
3867 static clockid_t thread_cpu_clockid(Thread* thread) {
|
|
3868 pthread_t tid = thread->osthread()->pthread_id();
|
|
3869 clockid_t clockid;
|
|
3870
|
|
3871 // Get thread clockid
|
|
3872 int rc = os::Linux::pthread_getcpuclockid(tid, &clockid);
|
|
3873 assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code");
|
|
3874 return clockid;
|
|
3875 }
|
|
3876
|
|
3877 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
|
|
3878 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
|
|
3879 // of a thread.
|
|
3880 //
|
|
3881 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
|
|
3882 // the fast estimate available on the platform.
|
|
3883
|
|
3884 jlong os::current_thread_cpu_time() {
|
|
3885 if (os::Linux::supports_fast_thread_cpu_time()) {
|
|
3886 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
|
|
3887 } else {
|
|
3888 // return user + sys since the cost is the same
|
|
3889 return slow_thread_cpu_time(Thread::current(), true /* user + sys */);
|
|
3890 }
|
|
3891 }
|
|
3892
|
|
3893 jlong os::thread_cpu_time(Thread* thread) {
|
|
3894 // consistent with what current_thread_cpu_time() returns
|
|
3895 if (os::Linux::supports_fast_thread_cpu_time()) {
|
|
3896 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread));
|
|
3897 } else {
|
|
3898 return slow_thread_cpu_time(thread, true /* user + sys */);
|
|
3899 }
|
|
3900 }
|
|
3901
|
|
3902 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
|
|
3903 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
|
|
3904 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
|
|
3905 } else {
|
|
3906 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time);
|
|
3907 }
|
|
3908 }
|
|
3909
|
|
3910 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
|
|
3911 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
|
|
3912 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread));
|
|
3913 } else {
|
|
3914 return slow_thread_cpu_time(thread, user_sys_cpu_time);
|
|
3915 }
|
|
3916 }
|
|
3917
|
|
3918 //
|
|
3919 // -1 on error.
|
|
3920 //
|
|
3921
|
|
3922 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
|
|
3923 static bool proc_pid_cpu_avail = true;
|
|
3924 static bool proc_task_unchecked = true;
|
|
3925 static const char *proc_stat_path = "/proc/%d/stat";
|
|
3926 pid_t tid = thread->osthread()->thread_id();
|
|
3927 int i;
|
|
3928 char *s;
|
|
3929 char stat[2048];
|
|
3930 int statlen;
|
|
3931 char proc_name[64];
|
|
3932 int count;
|
|
3933 long sys_time, user_time;
|
|
3934 char string[64];
|
|
3935 int idummy;
|
|
3936 long ldummy;
|
|
3937 FILE *fp;
|
|
3938
|
|
3939 // We first try accessing /proc/<pid>/cpu since this is faster to
|
|
3940 // process. If this file is not present (linux kernels 2.5 and above)
|
|
3941 // then we open /proc/<pid>/stat.
|
|
3942 if ( proc_pid_cpu_avail ) {
|
|
3943 sprintf(proc_name, "/proc/%d/cpu", tid);
|
|
3944 fp = fopen(proc_name, "r");
|
|
3945 if ( fp != NULL ) {
|
|
3946 count = fscanf( fp, "%s %lu %lu\n", string, &user_time, &sys_time);
|
|
3947 fclose(fp);
|
|
3948 if ( count != 3 ) return -1;
|
|
3949
|
|
3950 if (user_sys_cpu_time) {
|
|
3951 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
|
|
3952 } else {
|
|
3953 return (jlong)user_time * (1000000000 / clock_tics_per_sec);
|
|
3954 }
|
|
3955 }
|
|
3956 else proc_pid_cpu_avail = false;
|
|
3957 }
|
|
3958
|
|
3959 // The /proc/<tid>/stat aggregates per-process usage on
|
|
3960 // new Linux kernels 2.6+ where NPTL is supported.
|
|
3961 // The /proc/self/task/<tid>/stat still has the per-thread usage.
|
|
3962 // See bug 6328462.
|
|
3963 // There can be no directory /proc/self/task on kernels 2.4 with NPTL
|
|
3964 // and possibly in some other cases, so we check its availability.
|
|
3965 if (proc_task_unchecked && os::Linux::is_NPTL()) {
|
|
3966 // This is executed only once
|
|
3967 proc_task_unchecked = false;
|
|
3968 fp = fopen("/proc/self/task", "r");
|
|
3969 if (fp != NULL) {
|
|
3970 proc_stat_path = "/proc/self/task/%d/stat";
|
|
3971 fclose(fp);
|
|
3972 }
|
|
3973 }
|
|
3974
|
|
3975 sprintf(proc_name, proc_stat_path, tid);
|
|
3976 fp = fopen(proc_name, "r");
|
|
3977 if ( fp == NULL ) return -1;
|
|
3978 statlen = fread(stat, 1, 2047, fp);
|
|
3979 stat[statlen] = '\0';
|
|
3980 fclose(fp);
|
|
3981
|
|
3982 // Skip pid and the command string. Note that we could be dealing with
|
|
3983 // weird command names, e.g. user could decide to rename java launcher
|
|
3984 // to "java 1.4.2 :)", then the stat file would look like
|
|
3985 // 1234 (java 1.4.2 :)) R ... ...
|
|
3986 // We don't really need to know the command string, just find the last
|
|
3987 // occurrence of ")" and then start parsing from there. See bug 4726580.
|
|
3988 s = strrchr(stat, ')');
|
|
3989 i = 0;
|
|
3990 if (s == NULL ) return -1;
|
|
3991
|
|
3992 // Skip blank chars
|
|
3993 do s++; while (isspace(*s));
|
|
3994
|
|
3995 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu",
|
|
3996 &idummy, &idummy, &idummy, &idummy, &idummy, &idummy,
|
|
3997 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy,
|
|
3998 &user_time, &sys_time);
|
|
3999 if ( count != 13 ) return -1;
|
|
4000 if (user_sys_cpu_time) {
|
|
4001 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec);
|
|
4002 } else {
|
|
4003 return (jlong)user_time * (1000000000 / clock_tics_per_sec);
|
|
4004 }
|
|
4005 }
|
|
4006
|
|
4007 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
|
|
4008 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
|
|
4009 info_ptr->may_skip_backward = false; // elapsed time not wall time
|
|
4010 info_ptr->may_skip_forward = false; // elapsed time not wall time
|
|
4011 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
|
|
4012 }
|
|
4013
|
|
4014 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
|
|
4015 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
|
|
4016 info_ptr->may_skip_backward = false; // elapsed time not wall time
|
|
4017 info_ptr->may_skip_forward = false; // elapsed time not wall time
|
|
4018 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
|
|
4019 }
|
|
4020
|
|
4021 bool os::is_thread_cpu_time_supported() {
|
|
4022 return true;
|
|
4023 }
|
|
4024
|
|
4025 // System loadavg support. Returns -1 if load average cannot be obtained.
|
|
4026 // Linux doesn't yet have a (official) notion of processor sets,
|
|
4027 // so just return the system wide load average.
|
|
4028 int os::loadavg(double loadavg[], int nelem) {
|
|
4029 return ::getloadavg(loadavg, nelem);
|
|
4030 }
|
|
4031
|
|
4032 void os::pause() {
|
|
4033 char filename[MAX_PATH];
|
|
4034 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
|
|
4035 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
|
|
4036 } else {
|
|
4037 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
|
|
4038 }
|
|
4039
|
|
4040 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
|
|
4041 if (fd != -1) {
|
|
4042 struct stat buf;
|
|
4043 close(fd);
|
|
4044 while (::stat(filename, &buf) == 0) {
|
|
4045 (void)::poll(NULL, 0, 100);
|
|
4046 }
|
|
4047 } else {
|
|
4048 jio_fprintf(stderr,
|
|
4049 "Could not open pause file '%s', continuing immediately.\n", filename);
|
|
4050 }
|
|
4051 }
|
|
4052
|
|
4053 extern "C" {
|
|
4054
|
|
4055 /**
|
|
4056 * NOTE: the following code is to keep the green threads code
|
|
4057 * in the libjava.so happy. Once the green threads is removed,
|
|
4058 * these code will no longer be needed.
|
|
4059 */
|
|
4060 int
|
|
4061 jdk_waitpid(pid_t pid, int* status, int options) {
|
|
4062 return waitpid(pid, status, options);
|
|
4063 }
|
|
4064
|
|
4065 int
|
|
4066 fork1() {
|
|
4067 return fork();
|
|
4068 }
|
|
4069
|
|
4070 int
|
|
4071 jdk_sem_init(sem_t *sem, int pshared, unsigned int value) {
|
|
4072 return sem_init(sem, pshared, value);
|
|
4073 }
|
|
4074
|
|
4075 int
|
|
4076 jdk_sem_post(sem_t *sem) {
|
|
4077 return sem_post(sem);
|
|
4078 }
|
|
4079
|
|
4080 int
|
|
4081 jdk_sem_wait(sem_t *sem) {
|
|
4082 return sem_wait(sem);
|
|
4083 }
|
|
4084
|
|
4085 int
|
|
4086 jdk_pthread_sigmask(int how , const sigset_t* newmask, sigset_t* oldmask) {
|
|
4087 return pthread_sigmask(how , newmask, oldmask);
|
|
4088 }
|
|
4089
|
|
4090 }
|
|
4091
|
|
4092 // Refer to the comments in os_solaris.cpp park-unpark.
|
|
4093 //
|
|
4094 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
|
|
4095 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
|
|
4096 // For specifics regarding the bug see GLIBC BUGID 261237 :
|
|
4097 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
|
|
4098 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
|
|
4099 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
|
|
4100 // is used. (The simple C test-case provided in the GLIBC bug report manifests the
|
|
4101 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
|
|
4102 // and monitorenter when we're using 1-0 locking. All those operations may result in
|
|
4103 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version
|
|
4104 // of libpthread avoids the problem, but isn't practical.
|
|
4105 //
|
|
4106 // Possible remedies:
|
|
4107 //
|
|
4108 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work.
|
|
4109 // This is palliative and probabilistic, however. If the thread is preempted
|
|
4110 // between the call to compute_abstime() and pthread_cond_timedwait(), more
|
|
4111 // than the minimum period may have passed, and the abstime may be stale (in the
|
|
4112 // past) resultin in a hang. Using this technique reduces the odds of a hang
|
|
4113 // but the JVM is still vulnerable, particularly on heavily loaded systems.
|
|
4114 //
|
|
4115 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
|
|
4116 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set
|
|
4117 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
|
|
4118 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant
|
|
4119 // thread.
|
|
4120 //
|
|
4121 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread
|
|
4122 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing
|
|
4123 // a timeout request to the chron thread and then blocking via pthread_cond_wait().
|
|
4124 // This also works well. In fact it avoids kernel-level scalability impediments
|
|
4125 // on certain platforms that don't handle lots of active pthread_cond_timedwait()
|
|
4126 // timers in a graceful fashion.
|
|
4127 //
|
|
4128 // 4. When the abstime value is in the past it appears that control returns
|
|
4129 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
|
|
4130 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we
|
|
4131 // can avoid the problem by reinitializing the condvar -- by cond_destroy()
|
|
4132 // followed by cond_init() -- after all calls to pthread_cond_timedwait().
|
|
4133 // It may be possible to avoid reinitialization by checking the return
|
|
4134 // value from pthread_cond_timedwait(). In addition to reinitializing the
|
|
4135 // condvar we must establish the invariant that cond_signal() is only called
|
|
4136 // within critical sections protected by the adjunct mutex. This prevents
|
|
4137 // cond_signal() from "seeing" a condvar that's in the midst of being
|
|
4138 // reinitialized or that is corrupt. Sadly, this invariant obviates the
|
|
4139 // desirable signal-after-unlock optimization that avoids futile context switching.
|
|
4140 //
|
|
4141 // I'm also concerned that some versions of NTPL might allocate an auxilliary
|
|
4142 // structure when a condvar is used or initialized. cond_destroy() would
|
|
4143 // release the helper structure. Our reinitialize-after-timedwait fix
|
|
4144 // put excessive stress on malloc/free and locks protecting the c-heap.
|
|
4145 //
|
|
4146 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag.
|
|
4147 // It may be possible to refine (4) by checking the kernel and NTPL verisons
|
|
4148 // and only enabling the work-around for vulnerable environments.
|
|
4149
|
|
4150 // utility to compute the abstime argument to timedwait:
|
|
4151 // millis is the relative timeout time
|
|
4152 // abstime will be the absolute timeout time
|
|
4153 // TODO: replace compute_abstime() with unpackTime()
|
|
4154
|
|
4155 static struct timespec* compute_abstime(timespec* abstime, jlong millis) {
|
|
4156 if (millis < 0) millis = 0;
|
|
4157 struct timeval now;
|
|
4158 int status = gettimeofday(&now, NULL);
|
|
4159 assert(status == 0, "gettimeofday");
|
|
4160 jlong seconds = millis / 1000;
|
|
4161 millis %= 1000;
|
|
4162 if (seconds > 50000000) { // see man cond_timedwait(3T)
|
|
4163 seconds = 50000000;
|
|
4164 }
|
|
4165 abstime->tv_sec = now.tv_sec + seconds;
|
|
4166 long usec = now.tv_usec + millis * 1000;
|
|
4167 if (usec >= 1000000) {
|
|
4168 abstime->tv_sec += 1;
|
|
4169 usec -= 1000000;
|
|
4170 }
|
|
4171 abstime->tv_nsec = usec * 1000;
|
|
4172 return abstime;
|
|
4173 }
|
|
4174
|
|
4175
|
|
4176 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
|
|
4177 // Conceptually TryPark() should be equivalent to park(0).
|
|
4178
|
|
4179 int os::PlatformEvent::TryPark() {
|
|
4180 for (;;) {
|
|
4181 const int v = _Event ;
|
|
4182 guarantee ((v == 0) || (v == 1), "invariant") ;
|
|
4183 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ;
|
|
4184 }
|
|
4185 }
|
|
4186
|
|
4187 void os::PlatformEvent::park() { // AKA "down()"
|
|
4188 // Invariant: Only the thread associated with the Event/PlatformEvent
|
|
4189 // may call park().
|
|
4190 // TODO: assert that _Assoc != NULL or _Assoc == Self
|
|
4191 int v ;
|
|
4192 for (;;) {
|
|
4193 v = _Event ;
|
|
4194 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
|
|
4195 }
|
|
4196 guarantee (v >= 0, "invariant") ;
|
|
4197 if (v == 0) {
|
|
4198 // Do this the hard way by blocking ...
|
|
4199 int status = pthread_mutex_lock(_mutex);
|
|
4200 assert_status(status == 0, status, "mutex_lock");
|
|
4201 guarantee (_nParked == 0, "invariant") ;
|
|
4202 ++ _nParked ;
|
|
4203 while (_Event < 0) {
|
|
4204 status = pthread_cond_wait(_cond, _mutex);
|
|
4205 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
|
|
4206 // Treat this the same as if the wait was interrupted
|
|
4207 if (status == ETIME) { status = EINTR; }
|
|
4208 assert_status(status == 0 || status == EINTR, status, "cond_wait");
|
|
4209 }
|
|
4210 -- _nParked ;
|
|
4211
|
|
4212 // In theory we could move the ST of 0 into _Event past the unlock(),
|
|
4213 // but then we'd need a MEMBAR after the ST.
|
|
4214 _Event = 0 ;
|
|
4215 status = pthread_mutex_unlock(_mutex);
|
|
4216 assert_status(status == 0, status, "mutex_unlock");
|
|
4217 }
|
|
4218 guarantee (_Event >= 0, "invariant") ;
|
|
4219 }
|
|
4220
|
|
4221 int os::PlatformEvent::park(jlong millis) {
|
|
4222 guarantee (_nParked == 0, "invariant") ;
|
|
4223
|
|
4224 int v ;
|
|
4225 for (;;) {
|
|
4226 v = _Event ;
|
|
4227 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
|
|
4228 }
|
|
4229 guarantee (v >= 0, "invariant") ;
|
|
4230 if (v != 0) return OS_OK ;
|
|
4231
|
|
4232 // We do this the hard way, by blocking the thread.
|
|
4233 // Consider enforcing a minimum timeout value.
|
|
4234 struct timespec abst;
|
|
4235 compute_abstime(&abst, millis);
|
|
4236
|
|
4237 int ret = OS_TIMEOUT;
|
|
4238 int status = pthread_mutex_lock(_mutex);
|
|
4239 assert_status(status == 0, status, "mutex_lock");
|
|
4240 guarantee (_nParked == 0, "invariant") ;
|
|
4241 ++_nParked ;
|
|
4242
|
|
4243 // Object.wait(timo) will return because of
|
|
4244 // (a) notification
|
|
4245 // (b) timeout
|
|
4246 // (c) thread.interrupt
|
|
4247 //
|
|
4248 // Thread.interrupt and object.notify{All} both call Event::set.
|
|
4249 // That is, we treat thread.interrupt as a special case of notification.
|
|
4250 // The underlying Solaris implementation, cond_timedwait, admits
|
|
4251 // spurious/premature wakeups, but the JLS/JVM spec prevents the
|
|
4252 // JVM from making those visible to Java code. As such, we must
|
|
4253 // filter out spurious wakeups. We assume all ETIME returns are valid.
|
|
4254 //
|
|
4255 // TODO: properly differentiate simultaneous notify+interrupt.
|
|
4256 // In that case, we should propagate the notify to another waiter.
|
|
4257
|
|
4258 while (_Event < 0) {
|
|
4259 status = os::Linux::safe_cond_timedwait(_cond, _mutex, &abst);
|
|
4260 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
|
|
4261 pthread_cond_destroy (_cond);
|
|
4262 pthread_cond_init (_cond, NULL) ;
|
|
4263 }
|
|
4264 assert_status(status == 0 || status == EINTR ||
|
|
4265 status == ETIME || status == ETIMEDOUT,
|
|
4266 status, "cond_timedwait");
|
|
4267 if (!FilterSpuriousWakeups) break ; // previous semantics
|
|
4268 if (status == ETIME || status == ETIMEDOUT) break ;
|
|
4269 // We consume and ignore EINTR and spurious wakeups.
|
|
4270 }
|
|
4271 --_nParked ;
|
|
4272 if (_Event >= 0) {
|
|
4273 ret = OS_OK;
|
|
4274 }
|
|
4275 _Event = 0 ;
|
|
4276 status = pthread_mutex_unlock(_mutex);
|
|
4277 assert_status(status == 0, status, "mutex_unlock");
|
|
4278 assert (_nParked == 0, "invariant") ;
|
|
4279 return ret;
|
|
4280 }
|
|
4281
|
|
4282 void os::PlatformEvent::unpark() {
|
|
4283 int v, AnyWaiters ;
|
|
4284 for (;;) {
|
|
4285 v = _Event ;
|
|
4286 if (v > 0) {
|
|
4287 // The LD of _Event could have reordered or be satisfied
|
|
4288 // by a read-aside from this processor's write buffer.
|
|
4289 // To avoid problems execute a barrier and then
|
|
4290 // ratify the value.
|
|
4291 OrderAccess::fence() ;
|
|
4292 if (_Event == v) return ;
|
|
4293 continue ;
|
|
4294 }
|
|
4295 if (Atomic::cmpxchg (v+1, &_Event, v) == v) break ;
|
|
4296 }
|
|
4297 if (v < 0) {
|
|
4298 // Wait for the thread associated with the event to vacate
|
|
4299 int status = pthread_mutex_lock(_mutex);
|
|
4300 assert_status(status == 0, status, "mutex_lock");
|
|
4301 AnyWaiters = _nParked ;
|
|
4302 assert (AnyWaiters == 0 || AnyWaiters == 1, "invariant") ;
|
|
4303 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
|
|
4304 AnyWaiters = 0 ;
|
|
4305 pthread_cond_signal (_cond);
|
|
4306 }
|
|
4307 status = pthread_mutex_unlock(_mutex);
|
|
4308 assert_status(status == 0, status, "mutex_unlock");
|
|
4309 if (AnyWaiters != 0) {
|
|
4310 status = pthread_cond_signal(_cond);
|
|
4311 assert_status(status == 0, status, "cond_signal");
|
|
4312 }
|
|
4313 }
|
|
4314
|
|
4315 // Note that we signal() _after dropping the lock for "immortal" Events.
|
|
4316 // This is safe and avoids a common class of futile wakeups. In rare
|
|
4317 // circumstances this can cause a thread to return prematurely from
|
|
4318 // cond_{timed}wait() but the spurious wakeup is benign and the victim will
|
|
4319 // simply re-test the condition and re-park itself.
|
|
4320 }
|
|
4321
|
|
4322
|
|
4323 // JSR166
|
|
4324 // -------------------------------------------------------
|
|
4325
|
|
4326 /*
|
|
4327 * The solaris and linux implementations of park/unpark are fairly
|
|
4328 * conservative for now, but can be improved. They currently use a
|
|
4329 * mutex/condvar pair, plus a a count.
|
|
4330 * Park decrements count if > 0, else does a condvar wait. Unpark
|
|
4331 * sets count to 1 and signals condvar. Only one thread ever waits
|
|
4332 * on the condvar. Contention seen when trying to park implies that someone
|
|
4333 * is unparking you, so don't wait. And spurious returns are fine, so there
|
|
4334 * is no need to track notifications.
|
|
4335 */
|
|
4336
|
|
4337
|
|
4338 #define NANOSECS_PER_SEC 1000000000
|
|
4339 #define NANOSECS_PER_MILLISEC 1000000
|
|
4340 #define MAX_SECS 100000000
|
|
4341 /*
|
|
4342 * This code is common to linux and solaris and will be moved to a
|
|
4343 * common place in dolphin.
|
|
4344 *
|
|
4345 * The passed in time value is either a relative time in nanoseconds
|
|
4346 * or an absolute time in milliseconds. Either way it has to be unpacked
|
|
4347 * into suitable seconds and nanoseconds components and stored in the
|
|
4348 * given timespec structure.
|
|
4349 * Given time is a 64-bit value and the time_t used in the timespec is only
|
|
4350 * a signed-32-bit value (except on 64-bit Linux) we have to watch for
|
|
4351 * overflow if times way in the future are given. Further on Solaris versions
|
|
4352 * prior to 10 there is a restriction (see cond_timedwait) that the specified
|
|
4353 * number of seconds, in abstime, is less than current_time + 100,000,000.
|
|
4354 * As it will be 28 years before "now + 100000000" will overflow we can
|
|
4355 * ignore overflow and just impose a hard-limit on seconds using the value
|
|
4356 * of "now + 100,000,000". This places a limit on the timeout of about 3.17
|
|
4357 * years from "now".
|
|
4358 */
|
|
4359
|
|
4360 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time) {
|
|
4361 assert (time > 0, "convertTime");
|
|
4362
|
|
4363 struct timeval now;
|
|
4364 int status = gettimeofday(&now, NULL);
|
|
4365 assert(status == 0, "gettimeofday");
|
|
4366
|
|
4367 time_t max_secs = now.tv_sec + MAX_SECS;
|
|
4368
|
|
4369 if (isAbsolute) {
|
|
4370 jlong secs = time / 1000;
|
|
4371 if (secs > max_secs) {
|
|
4372 absTime->tv_sec = max_secs;
|
|
4373 }
|
|
4374 else {
|
|
4375 absTime->tv_sec = secs;
|
|
4376 }
|
|
4377 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
|
|
4378 }
|
|
4379 else {
|
|
4380 jlong secs = time / NANOSECS_PER_SEC;
|
|
4381 if (secs >= MAX_SECS) {
|
|
4382 absTime->tv_sec = max_secs;
|
|
4383 absTime->tv_nsec = 0;
|
|
4384 }
|
|
4385 else {
|
|
4386 absTime->tv_sec = now.tv_sec + secs;
|
|
4387 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
|
|
4388 if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
|
|
4389 absTime->tv_nsec -= NANOSECS_PER_SEC;
|
|
4390 ++absTime->tv_sec; // note: this must be <= max_secs
|
|
4391 }
|
|
4392 }
|
|
4393 }
|
|
4394 assert(absTime->tv_sec >= 0, "tv_sec < 0");
|
|
4395 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
|
|
4396 assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
|
|
4397 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
|
|
4398 }
|
|
4399
|
|
4400 void Parker::park(bool isAbsolute, jlong time) {
|
|
4401 // Optional fast-path check:
|
|
4402 // Return immediately if a permit is available.
|
|
4403 if (_counter > 0) {
|
|
4404 _counter = 0 ;
|
|
4405 return ;
|
|
4406 }
|
|
4407
|
|
4408 Thread* thread = Thread::current();
|
|
4409 assert(thread->is_Java_thread(), "Must be JavaThread");
|
|
4410 JavaThread *jt = (JavaThread *)thread;
|
|
4411
|
|
4412 // Optional optimization -- avoid state transitions if there's an interrupt pending.
|
|
4413 // Check interrupt before trying to wait
|
|
4414 if (Thread::is_interrupted(thread, false)) {
|
|
4415 return;
|
|
4416 }
|
|
4417
|
|
4418 // Next, demultiplex/decode time arguments
|
|
4419 timespec absTime;
|
|
4420 if (time < 0) { // don't wait at all
|
|
4421 return;
|
|
4422 }
|
|
4423 if (time > 0) {
|
|
4424 unpackTime(&absTime, isAbsolute, time);
|
|
4425 }
|
|
4426
|
|
4427
|
|
4428 // Enter safepoint region
|
|
4429 // Beware of deadlocks such as 6317397.
|
|
4430 // The per-thread Parker:: mutex is a classic leaf-lock.
|
|
4431 // In particular a thread must never block on the Threads_lock while
|
|
4432 // holding the Parker:: mutex. If safepoints are pending both the
|
|
4433 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
|
|
4434 ThreadBlockInVM tbivm(jt);
|
|
4435
|
|
4436 // Don't wait if cannot get lock since interference arises from
|
|
4437 // unblocking. Also. check interrupt before trying wait
|
|
4438 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
|
|
4439 return;
|
|
4440 }
|
|
4441
|
|
4442 int status ;
|
|
4443 if (_counter > 0) { // no wait needed
|
|
4444 _counter = 0;
|
|
4445 status = pthread_mutex_unlock(_mutex);
|
|
4446 assert (status == 0, "invariant") ;
|
|
4447 return;
|
|
4448 }
|
|
4449
|
|
4450 #ifdef ASSERT
|
|
4451 // Don't catch signals while blocked; let the running threads have the signals.
|
|
4452 // (This allows a debugger to break into the running thread.)
|
|
4453 sigset_t oldsigs;
|
|
4454 sigset_t* allowdebug_blocked = os::Linux::allowdebug_blocked_signals();
|
|
4455 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
|
|
4456 #endif
|
|
4457
|
|
4458 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
|
|
4459 jt->set_suspend_equivalent();
|
|
4460 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
|
|
4461
|
|
4462 if (time == 0) {
|
|
4463 status = pthread_cond_wait (_cond, _mutex) ;
|
|
4464 } else {
|
|
4465 status = os::Linux::safe_cond_timedwait (_cond, _mutex, &absTime) ;
|
|
4466 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
|
|
4467 pthread_cond_destroy (_cond) ;
|
|
4468 pthread_cond_init (_cond, NULL);
|
|
4469 }
|
|
4470 }
|
|
4471 assert_status(status == 0 || status == EINTR ||
|
|
4472 status == ETIME || status == ETIMEDOUT,
|
|
4473 status, "cond_timedwait");
|
|
4474
|
|
4475 #ifdef ASSERT
|
|
4476 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
|
|
4477 #endif
|
|
4478
|
|
4479 _counter = 0 ;
|
|
4480 status = pthread_mutex_unlock(_mutex) ;
|
|
4481 assert_status(status == 0, status, "invariant") ;
|
|
4482 // If externally suspended while waiting, re-suspend
|
|
4483 if (jt->handle_special_suspend_equivalent_condition()) {
|
|
4484 jt->java_suspend_self();
|
|
4485 }
|
|
4486
|
|
4487 }
|
|
4488
|
|
4489 void Parker::unpark() {
|
|
4490 int s, status ;
|
|
4491 status = pthread_mutex_lock(_mutex);
|
|
4492 assert (status == 0, "invariant") ;
|
|
4493 s = _counter;
|
|
4494 _counter = 1;
|
|
4495 if (s < 1) {
|
|
4496 if (WorkAroundNPTLTimedWaitHang) {
|
|
4497 status = pthread_cond_signal (_cond) ;
|
|
4498 assert (status == 0, "invariant") ;
|
|
4499 status = pthread_mutex_unlock(_mutex);
|
|
4500 assert (status == 0, "invariant") ;
|
|
4501 } else {
|
|
4502 status = pthread_mutex_unlock(_mutex);
|
|
4503 assert (status == 0, "invariant") ;
|
|
4504 status = pthread_cond_signal (_cond) ;
|
|
4505 assert (status == 0, "invariant") ;
|
|
4506 }
|
|
4507 } else {
|
|
4508 pthread_mutex_unlock(_mutex);
|
|
4509 assert (status == 0, "invariant") ;
|
|
4510 }
|
|
4511 }
|
|
4512
|
|
4513
|
|
4514 extern char** environ;
|
|
4515
|
|
4516 #ifndef __NR_fork
|
|
4517 #define __NR_fork IA32_ONLY(2) IA64_ONLY(not defined) AMD64_ONLY(57)
|
|
4518 #endif
|
|
4519
|
|
4520 #ifndef __NR_execve
|
|
4521 #define __NR_execve IA32_ONLY(11) IA64_ONLY(1033) AMD64_ONLY(59)
|
|
4522 #endif
|
|
4523
|
|
4524 // Run the specified command in a separate process. Return its exit value,
|
|
4525 // or -1 on failure (e.g. can't fork a new process).
|
|
4526 // Unlike system(), this function can be called from signal handler. It
|
|
4527 // doesn't block SIGINT et al.
|
|
4528 int os::fork_and_exec(char* cmd) {
|
|
4529 char * argv[4];
|
|
4530 argv[0] = "sh";
|
|
4531 argv[1] = "-c";
|
|
4532 argv[2] = cmd;
|
|
4533 argv[3] = NULL;
|
|
4534
|
|
4535 // fork() in LinuxThreads/NPTL is not async-safe. It needs to run
|
|
4536 // pthread_atfork handlers and reset pthread library. All we need is a
|
|
4537 // separate process to execve. Make a direct syscall to fork process.
|
|
4538 // On IA64 there's no fork syscall, we have to use fork() and hope for
|
|
4539 // the best...
|
|
4540 pid_t pid = NOT_IA64(syscall(__NR_fork);)
|
|
4541 IA64_ONLY(fork();)
|
|
4542
|
|
4543 if (pid < 0) {
|
|
4544 // fork failed
|
|
4545 return -1;
|
|
4546
|
|
4547 } else if (pid == 0) {
|
|
4548 // child process
|
|
4549
|
|
4550 // execve() in LinuxThreads will call pthread_kill_other_threads_np()
|
|
4551 // first to kill every thread on the thread list. Because this list is
|
|
4552 // not reset by fork() (see notes above), execve() will instead kill
|
|
4553 // every thread in the parent process. We know this is the only thread
|
|
4554 // in the new process, so make a system call directly.
|
|
4555 // IA64 should use normal execve() from glibc to match the glibc fork()
|
|
4556 // above.
|
|
4557 NOT_IA64(syscall(__NR_execve, "/bin/sh", argv, environ);)
|
|
4558 IA64_ONLY(execve("/bin/sh", argv, environ);)
|
|
4559
|
|
4560 // execve failed
|
|
4561 _exit(-1);
|
|
4562
|
|
4563 } else {
|
|
4564 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
|
|
4565 // care about the actual exit code, for now.
|
|
4566
|
|
4567 int status;
|
|
4568
|
|
4569 // Wait for the child process to exit. This returns immediately if
|
|
4570 // the child has already exited. */
|
|
4571 while (waitpid(pid, &status, 0) < 0) {
|
|
4572 switch (errno) {
|
|
4573 case ECHILD: return 0;
|
|
4574 case EINTR: break;
|
|
4575 default: return -1;
|
|
4576 }
|
|
4577 }
|
|
4578
|
|
4579 if (WIFEXITED(status)) {
|
|
4580 // The child exited normally; get its exit code.
|
|
4581 return WEXITSTATUS(status);
|
|
4582 } else if (WIFSIGNALED(status)) {
|
|
4583 // The child exited because of a signal
|
|
4584 // The best value to return is 0x80 + signal number,
|
|
4585 // because that is what all Unix shells do, and because
|
|
4586 // it allows callers to distinguish between process exit and
|
|
4587 // process death by signal.
|
|
4588 return 0x80 + WTERMSIG(status);
|
|
4589 } else {
|
|
4590 // Unknown exit code; pass it through
|
|
4591 return status;
|
|
4592 }
|
|
4593 }
|
|
4594 }
|