Mercurial > hg > truffle
annotate src/os/linux/vm/os_linux.cpp @ 270:b7f01ad69d30
Merge
author | jmasa |
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date | Mon, 04 Aug 2008 12:11:36 -0700 |
parents | 850fdf70db2b d95b224e9f17 |
children | 1ee8caae33af |
rev | line source |
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0 | 1 /* |
196 | 2 * Copyright 1999-2008 Sun Microsystems, Inc. All Rights Reserved. |
0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 // do not include precompiled header file | |
26 # include "incls/_os_linux.cpp.incl" | |
27 | |
28 // put OS-includes here | |
29 # include <sys/types.h> | |
30 # include <sys/mman.h> | |
31 # include <pthread.h> | |
32 # include <signal.h> | |
33 # include <errno.h> | |
34 # include <dlfcn.h> | |
35 # include <stdio.h> | |
36 # include <unistd.h> | |
37 # include <sys/resource.h> | |
38 # include <pthread.h> | |
39 # include <sys/stat.h> | |
40 # include <sys/time.h> | |
41 # include <sys/times.h> | |
42 # include <sys/utsname.h> | |
43 # include <sys/socket.h> | |
44 # include <sys/wait.h> | |
45 # include <pwd.h> | |
46 # include <poll.h> | |
47 # include <semaphore.h> | |
48 # include <fcntl.h> | |
49 # include <string.h> | |
50 # include <syscall.h> | |
51 # include <sys/sysinfo.h> | |
52 # include <gnu/libc-version.h> | |
53 # include <sys/ipc.h> | |
54 # include <sys/shm.h> | |
55 # include <link.h> | |
56 | |
57 #define MAX_PATH (2 * K) | |
58 | |
59 // for timer info max values which include all bits | |
60 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) | |
61 #define SEC_IN_NANOSECS 1000000000LL | |
62 | |
63 //////////////////////////////////////////////////////////////////////////////// | |
64 // global variables | |
65 julong os::Linux::_physical_memory = 0; | |
66 | |
67 address os::Linux::_initial_thread_stack_bottom = NULL; | |
68 uintptr_t os::Linux::_initial_thread_stack_size = 0; | |
69 | |
70 int (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL; | |
71 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL; | |
72 Mutex* os::Linux::_createThread_lock = NULL; | |
73 pthread_t os::Linux::_main_thread; | |
74 int os::Linux::_page_size = -1; | |
75 bool os::Linux::_is_floating_stack = false; | |
76 bool os::Linux::_is_NPTL = false; | |
77 bool os::Linux::_supports_fast_thread_cpu_time = false; | |
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78 const char * os::Linux::_glibc_version = NULL; |
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79 const char * os::Linux::_libpthread_version = NULL; |
0 | 80 |
81 static jlong initial_time_count=0; | |
82 | |
83 static int clock_tics_per_sec = 100; | |
84 | |
85 // For diagnostics to print a message once. see run_periodic_checks | |
86 static sigset_t check_signal_done; | |
87 static bool check_signals = true;; | |
88 | |
89 static pid_t _initial_pid = 0; | |
90 | |
91 /* Signal number used to suspend/resume a thread */ | |
92 | |
93 /* do not use any signal number less than SIGSEGV, see 4355769 */ | |
94 static int SR_signum = SIGUSR2; | |
95 sigset_t SR_sigset; | |
96 | |
242 | 97 /* Used to protect dlsym() calls */ |
98 static pthread_mutex_t dl_mutex; | |
99 | |
0 | 100 //////////////////////////////////////////////////////////////////////////////// |
101 // utility functions | |
102 | |
103 static int SR_initialize(); | |
104 static int SR_finalize(); | |
105 | |
106 julong os::available_memory() { | |
107 return Linux::available_memory(); | |
108 } | |
109 | |
110 julong os::Linux::available_memory() { | |
111 // values in struct sysinfo are "unsigned long" | |
112 struct sysinfo si; | |
113 sysinfo(&si); | |
114 | |
115 return (julong)si.freeram * si.mem_unit; | |
116 } | |
117 | |
118 julong os::physical_memory() { | |
119 return Linux::physical_memory(); | |
120 } | |
121 | |
20
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122 julong os::allocatable_physical_memory(julong size) { |
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123 #ifdef _LP64 |
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124 return size; |
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125 #else |
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126 julong result = MIN2(size, (julong)3800*M); |
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127 if (!is_allocatable(result)) { |
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128 // See comments under solaris for alignment considerations |
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129 julong reasonable_size = (julong)2*G - 2 * os::vm_page_size(); |
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130 result = MIN2(size, reasonable_size); |
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131 } |
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132 return result; |
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133 #endif // _LP64 |
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134 } |
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135 |
0 | 136 //////////////////////////////////////////////////////////////////////////////// |
137 // environment support | |
138 | |
139 bool os::getenv(const char* name, char* buf, int len) { | |
140 const char* val = ::getenv(name); | |
141 if (val != NULL && strlen(val) < (size_t)len) { | |
142 strcpy(buf, val); | |
143 return true; | |
144 } | |
145 if (len > 0) buf[0] = 0; // return a null string | |
146 return false; | |
147 } | |
148 | |
149 | |
150 // Return true if user is running as root. | |
151 | |
152 bool os::have_special_privileges() { | |
153 static bool init = false; | |
154 static bool privileges = false; | |
155 if (!init) { | |
156 privileges = (getuid() != geteuid()) || (getgid() != getegid()); | |
157 init = true; | |
158 } | |
159 return privileges; | |
160 } | |
161 | |
162 | |
163 #ifndef SYS_gettid | |
164 // i386: 224, ia64: 1105, amd64: 186, sparc 143 | |
165 #ifdef __ia64__ | |
166 #define SYS_gettid 1105 | |
167 #elif __i386__ | |
168 #define SYS_gettid 224 | |
169 #elif __amd64__ | |
170 #define SYS_gettid 186 | |
171 #elif __sparc__ | |
172 #define SYS_gettid 143 | |
173 #else | |
174 #error define gettid for the arch | |
175 #endif | |
176 #endif | |
177 | |
178 // Cpu architecture string | |
179 #if defined(IA64) | |
180 static char cpu_arch[] = "ia64"; | |
181 #elif defined(IA32) | |
182 static char cpu_arch[] = "i386"; | |
183 #elif defined(AMD64) | |
184 static char cpu_arch[] = "amd64"; | |
185 #elif defined(SPARC) | |
186 # ifdef _LP64 | |
187 static char cpu_arch[] = "sparcv9"; | |
188 # else | |
189 static char cpu_arch[] = "sparc"; | |
190 # endif | |
191 #else | |
192 #error Add appropriate cpu_arch setting | |
193 #endif | |
194 | |
195 | |
196 // pid_t gettid() | |
197 // | |
198 // Returns the kernel thread id of the currently running thread. Kernel | |
199 // thread id is used to access /proc. | |
200 // | |
201 // (Note that getpid() on LinuxThreads returns kernel thread id too; but | |
202 // on NPTL, it returns the same pid for all threads, as required by POSIX.) | |
203 // | |
204 pid_t os::Linux::gettid() { | |
205 int rslt = syscall(SYS_gettid); | |
206 if (rslt == -1) { | |
207 // old kernel, no NPTL support | |
208 return getpid(); | |
209 } else { | |
210 return (pid_t)rslt; | |
211 } | |
212 } | |
213 | |
214 // Most versions of linux have a bug where the number of processors are | |
215 // determined by looking at the /proc file system. In a chroot environment, | |
216 // the system call returns 1. This causes the VM to act as if it is | |
217 // a single processor and elide locking (see is_MP() call). | |
218 static bool unsafe_chroot_detected = false; | |
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219 static const char *unstable_chroot_error = "/proc file system not found.\n" |
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220 "Java may be unstable running multithreaded in a chroot " |
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221 "environment on Linux when /proc filesystem is not mounted."; |
0 | 222 |
223 void os::Linux::initialize_system_info() { | |
224 _processor_count = sysconf(_SC_NPROCESSORS_CONF); | |
225 if (_processor_count == 1) { | |
226 pid_t pid = os::Linux::gettid(); | |
227 char fname[32]; | |
228 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid); | |
229 FILE *fp = fopen(fname, "r"); | |
230 if (fp == NULL) { | |
231 unsafe_chroot_detected = true; | |
232 } else { | |
233 fclose(fp); | |
234 } | |
235 } | |
236 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE); | |
237 assert(_processor_count > 0, "linux error"); | |
238 } | |
239 | |
240 void os::init_system_properties_values() { | |
241 // char arch[12]; | |
242 // sysinfo(SI_ARCHITECTURE, arch, sizeof(arch)); | |
243 | |
244 // The next steps are taken in the product version: | |
245 // | |
246 // Obtain the JAVA_HOME value from the location of libjvm[_g].so. | |
247 // This library should be located at: | |
248 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm[_g].so. | |
249 // | |
250 // If "/jre/lib/" appears at the right place in the path, then we | |
251 // assume libjvm[_g].so is installed in a JDK and we use this path. | |
252 // | |
253 // Otherwise exit with message: "Could not create the Java virtual machine." | |
254 // | |
255 // The following extra steps are taken in the debugging version: | |
256 // | |
257 // If "/jre/lib/" does NOT appear at the right place in the path | |
258 // instead of exit check for $JAVA_HOME environment variable. | |
259 // | |
260 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, | |
261 // then we append a fake suffix "hotspot/libjvm[_g].so" to this path so | |
262 // it looks like libjvm[_g].so is installed there | |
263 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm[_g].so. | |
264 // | |
265 // Otherwise exit. | |
266 // | |
267 // Important note: if the location of libjvm.so changes this | |
268 // code needs to be changed accordingly. | |
269 | |
270 // The next few definitions allow the code to be verbatim: | |
271 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n)) | |
272 #define getenv(n) ::getenv(n) | |
273 | |
274 /* | |
275 * See ld(1): | |
276 * The linker uses the following search paths to locate required | |
277 * shared libraries: | |
278 * 1: ... | |
279 * ... | |
280 * 7: The default directories, normally /lib and /usr/lib. | |
281 */ | |
282 #define DEFAULT_LIBPATH "/lib:/usr/lib" | |
283 | |
284 #define EXTENSIONS_DIR "/lib/ext" | |
285 #define ENDORSED_DIR "/lib/endorsed" | |
286 #define REG_DIR "/usr/java/packages" | |
287 | |
288 { | |
289 /* sysclasspath, java_home, dll_dir */ | |
290 { | |
291 char *home_path; | |
292 char *dll_path; | |
293 char *pslash; | |
294 char buf[MAXPATHLEN]; | |
295 os::jvm_path(buf, sizeof(buf)); | |
296 | |
297 // Found the full path to libjvm.so. | |
298 // Now cut the path to <java_home>/jre if we can. | |
299 *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */ | |
300 pslash = strrchr(buf, '/'); | |
301 if (pslash != NULL) | |
302 *pslash = '\0'; /* get rid of /{client|server|hotspot} */ | |
303 dll_path = malloc(strlen(buf) + 1); | |
304 if (dll_path == NULL) | |
305 return; | |
306 strcpy(dll_path, buf); | |
307 Arguments::set_dll_dir(dll_path); | |
308 | |
309 if (pslash != NULL) { | |
310 pslash = strrchr(buf, '/'); | |
311 if (pslash != NULL) { | |
312 *pslash = '\0'; /* get rid of /<arch> */ | |
313 pslash = strrchr(buf, '/'); | |
314 if (pslash != NULL) | |
315 *pslash = '\0'; /* get rid of /lib */ | |
316 } | |
317 } | |
318 | |
319 home_path = malloc(strlen(buf) + 1); | |
320 if (home_path == NULL) | |
321 return; | |
322 strcpy(home_path, buf); | |
323 Arguments::set_java_home(home_path); | |
324 | |
325 if (!set_boot_path('/', ':')) | |
326 return; | |
327 } | |
328 | |
329 /* | |
330 * Where to look for native libraries | |
331 * | |
332 * Note: Due to a legacy implementation, most of the library path | |
333 * is set in the launcher. This was to accomodate linking restrictions | |
334 * on legacy Linux implementations (which are no longer supported). | |
335 * Eventually, all the library path setting will be done here. | |
336 * | |
337 * However, to prevent the proliferation of improperly built native | |
338 * libraries, the new path component /usr/java/packages is added here. | |
339 * Eventually, all the library path setting will be done here. | |
340 */ | |
341 { | |
342 char *ld_library_path; | |
343 | |
344 /* | |
345 * Construct the invariant part of ld_library_path. Note that the | |
346 * space for the colon and the trailing null are provided by the | |
347 * nulls included by the sizeof operator (so actually we allocate | |
348 * a byte more than necessary). | |
349 */ | |
350 ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") + | |
351 strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH)); | |
352 sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch); | |
353 | |
354 /* | |
355 * Get the user setting of LD_LIBRARY_PATH, and prepended it. It | |
356 * should always exist (until the legacy problem cited above is | |
357 * addressed). | |
358 */ | |
359 char *v = getenv("LD_LIBRARY_PATH"); | |
360 if (v != NULL) { | |
361 char *t = ld_library_path; | |
362 /* That's +1 for the colon and +1 for the trailing '\0' */ | |
363 ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1); | |
364 sprintf(ld_library_path, "%s:%s", v, t); | |
365 } | |
366 Arguments::set_library_path(ld_library_path); | |
367 } | |
368 | |
369 /* | |
370 * Extensions directories. | |
371 * | |
372 * Note that the space for the colon and the trailing null are provided | |
373 * by the nulls included by the sizeof operator (so actually one byte more | |
374 * than necessary is allocated). | |
375 */ | |
376 { | |
377 char *buf = malloc(strlen(Arguments::get_java_home()) + | |
378 sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR)); | |
379 sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR, | |
380 Arguments::get_java_home()); | |
381 Arguments::set_ext_dirs(buf); | |
382 } | |
383 | |
384 /* Endorsed standards default directory. */ | |
385 { | |
386 char * buf; | |
387 buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR)); | |
388 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home()); | |
389 Arguments::set_endorsed_dirs(buf); | |
390 } | |
391 } | |
392 | |
393 #undef malloc | |
394 #undef getenv | |
395 #undef EXTENSIONS_DIR | |
396 #undef ENDORSED_DIR | |
397 | |
398 // Done | |
399 return; | |
400 } | |
401 | |
402 //////////////////////////////////////////////////////////////////////////////// | |
403 // breakpoint support | |
404 | |
405 void os::breakpoint() { | |
406 BREAKPOINT; | |
407 } | |
408 | |
409 extern "C" void breakpoint() { | |
410 // use debugger to set breakpoint here | |
411 } | |
412 | |
413 //////////////////////////////////////////////////////////////////////////////// | |
414 // signal support | |
415 | |
416 debug_only(static bool signal_sets_initialized = false); | |
417 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs; | |
418 | |
419 bool os::Linux::is_sig_ignored(int sig) { | |
420 struct sigaction oact; | |
421 sigaction(sig, (struct sigaction*)NULL, &oact); | |
422 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) | |
423 : CAST_FROM_FN_PTR(void*, oact.sa_handler); | |
424 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) | |
425 return true; | |
426 else | |
427 return false; | |
428 } | |
429 | |
430 void os::Linux::signal_sets_init() { | |
431 // Should also have an assertion stating we are still single-threaded. | |
432 assert(!signal_sets_initialized, "Already initialized"); | |
433 // Fill in signals that are necessarily unblocked for all threads in | |
434 // the VM. Currently, we unblock the following signals: | |
435 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden | |
436 // by -Xrs (=ReduceSignalUsage)); | |
437 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all | |
438 // other threads. The "ReduceSignalUsage" boolean tells us not to alter | |
439 // the dispositions or masks wrt these signals. | |
440 // Programs embedding the VM that want to use the above signals for their | |
441 // own purposes must, at this time, use the "-Xrs" option to prevent | |
442 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. | |
443 // (See bug 4345157, and other related bugs). | |
444 // In reality, though, unblocking these signals is really a nop, since | |
445 // these signals are not blocked by default. | |
446 sigemptyset(&unblocked_sigs); | |
447 sigemptyset(&allowdebug_blocked_sigs); | |
448 sigaddset(&unblocked_sigs, SIGILL); | |
449 sigaddset(&unblocked_sigs, SIGSEGV); | |
450 sigaddset(&unblocked_sigs, SIGBUS); | |
451 sigaddset(&unblocked_sigs, SIGFPE); | |
452 sigaddset(&unblocked_sigs, SR_signum); | |
453 | |
454 if (!ReduceSignalUsage) { | |
455 if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) { | |
456 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); | |
457 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL); | |
458 } | |
459 if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) { | |
460 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); | |
461 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL); | |
462 } | |
463 if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) { | |
464 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); | |
465 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL); | |
466 } | |
467 } | |
468 // Fill in signals that are blocked by all but the VM thread. | |
469 sigemptyset(&vm_sigs); | |
470 if (!ReduceSignalUsage) | |
471 sigaddset(&vm_sigs, BREAK_SIGNAL); | |
472 debug_only(signal_sets_initialized = true); | |
473 | |
474 } | |
475 | |
476 // These are signals that are unblocked while a thread is running Java. | |
477 // (For some reason, they get blocked by default.) | |
478 sigset_t* os::Linux::unblocked_signals() { | |
479 assert(signal_sets_initialized, "Not initialized"); | |
480 return &unblocked_sigs; | |
481 } | |
482 | |
483 // These are the signals that are blocked while a (non-VM) thread is | |
484 // running Java. Only the VM thread handles these signals. | |
485 sigset_t* os::Linux::vm_signals() { | |
486 assert(signal_sets_initialized, "Not initialized"); | |
487 return &vm_sigs; | |
488 } | |
489 | |
490 // These are signals that are blocked during cond_wait to allow debugger in | |
491 sigset_t* os::Linux::allowdebug_blocked_signals() { | |
492 assert(signal_sets_initialized, "Not initialized"); | |
493 return &allowdebug_blocked_sigs; | |
494 } | |
495 | |
496 void os::Linux::hotspot_sigmask(Thread* thread) { | |
497 | |
498 //Save caller's signal mask before setting VM signal mask | |
499 sigset_t caller_sigmask; | |
500 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); | |
501 | |
502 OSThread* osthread = thread->osthread(); | |
503 osthread->set_caller_sigmask(caller_sigmask); | |
504 | |
505 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL); | |
506 | |
507 if (!ReduceSignalUsage) { | |
508 if (thread->is_VM_thread()) { | |
509 // Only the VM thread handles BREAK_SIGNAL ... | |
510 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); | |
511 } else { | |
512 // ... all other threads block BREAK_SIGNAL | |
513 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); | |
514 } | |
515 } | |
516 } | |
517 | |
518 ////////////////////////////////////////////////////////////////////////////// | |
519 // detecting pthread library | |
520 | |
521 void os::Linux::libpthread_init() { | |
522 // Save glibc and pthread version strings. Note that _CS_GNU_LIBC_VERSION | |
523 // and _CS_GNU_LIBPTHREAD_VERSION are supported in glibc >= 2.3.2. Use a | |
524 // generic name for earlier versions. | |
525 // Define macros here so we can build HotSpot on old systems. | |
526 # ifndef _CS_GNU_LIBC_VERSION | |
527 # define _CS_GNU_LIBC_VERSION 2 | |
528 # endif | |
529 # ifndef _CS_GNU_LIBPTHREAD_VERSION | |
530 # define _CS_GNU_LIBPTHREAD_VERSION 3 | |
531 # endif | |
532 | |
533 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); | |
534 if (n > 0) { | |
535 char *str = (char *)malloc(n); | |
536 confstr(_CS_GNU_LIBC_VERSION, str, n); | |
537 os::Linux::set_glibc_version(str); | |
538 } else { | |
539 // _CS_GNU_LIBC_VERSION is not supported, try gnu_get_libc_version() | |
540 static char _gnu_libc_version[32]; | |
541 jio_snprintf(_gnu_libc_version, sizeof(_gnu_libc_version), | |
542 "glibc %s %s", gnu_get_libc_version(), gnu_get_libc_release()); | |
543 os::Linux::set_glibc_version(_gnu_libc_version); | |
544 } | |
545 | |
546 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); | |
547 if (n > 0) { | |
548 char *str = (char *)malloc(n); | |
549 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); | |
550 // Vanilla RH-9 (glibc 2.3.2) has a bug that confstr() always tells | |
551 // us "NPTL-0.29" even we are running with LinuxThreads. Check if this | |
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552 // is the case. LinuxThreads has a hard limit on max number of threads. |
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553 // So sysconf(_SC_THREAD_THREADS_MAX) will return a positive value. |
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554 // On the other hand, NPTL does not have such a limit, sysconf() |
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555 // will return -1 and errno is not changed. Check if it is really NPTL. |
0 | 556 if (strcmp(os::Linux::glibc_version(), "glibc 2.3.2") == 0 && |
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557 strstr(str, "NPTL") && |
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558 sysconf(_SC_THREAD_THREADS_MAX) > 0) { |
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559 free(str); |
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560 os::Linux::set_libpthread_version("linuxthreads"); |
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561 } else { |
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562 os::Linux::set_libpthread_version(str); |
0 | 563 } |
564 } else { | |
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565 // glibc before 2.3.2 only has LinuxThreads. |
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566 os::Linux::set_libpthread_version("linuxthreads"); |
0 | 567 } |
568 | |
569 if (strstr(libpthread_version(), "NPTL")) { | |
570 os::Linux::set_is_NPTL(); | |
571 } else { | |
572 os::Linux::set_is_LinuxThreads(); | |
573 } | |
574 | |
575 // LinuxThreads have two flavors: floating-stack mode, which allows variable | |
576 // stack size; and fixed-stack mode. NPTL is always floating-stack. | |
577 if (os::Linux::is_NPTL() || os::Linux::supports_variable_stack_size()) { | |
578 os::Linux::set_is_floating_stack(); | |
579 } | |
580 } | |
581 | |
582 ///////////////////////////////////////////////////////////////////////////// | |
583 // thread stack | |
584 | |
585 // Force Linux kernel to expand current thread stack. If "bottom" is close | |
586 // to the stack guard, caller should block all signals. | |
587 // | |
588 // MAP_GROWSDOWN: | |
589 // A special mmap() flag that is used to implement thread stacks. It tells | |
590 // kernel that the memory region should extend downwards when needed. This | |
591 // allows early versions of LinuxThreads to only mmap the first few pages | |
592 // when creating a new thread. Linux kernel will automatically expand thread | |
593 // stack as needed (on page faults). | |
594 // | |
595 // However, because the memory region of a MAP_GROWSDOWN stack can grow on | |
596 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN | |
597 // region, it's hard to tell if the fault is due to a legitimate stack | |
598 // access or because of reading/writing non-exist memory (e.g. buffer | |
599 // overrun). As a rule, if the fault happens below current stack pointer, | |
600 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the | |
601 // application (see Linux kernel fault.c). | |
602 // | |
603 // This Linux feature can cause SIGSEGV when VM bangs thread stack for | |
604 // stack overflow detection. | |
605 // | |
606 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do | |
607 // not use this flag. However, the stack of initial thread is not created | |
608 // by pthread, it is still MAP_GROWSDOWN. Also it's possible (though | |
609 // unlikely) that user code can create a thread with MAP_GROWSDOWN stack | |
610 // and then attach the thread to JVM. | |
611 // | |
612 // To get around the problem and allow stack banging on Linux, we need to | |
613 // manually expand thread stack after receiving the SIGSEGV. | |
614 // | |
615 // There are two ways to expand thread stack to address "bottom", we used | |
616 // both of them in JVM before 1.5: | |
617 // 1. adjust stack pointer first so that it is below "bottom", and then | |
618 // touch "bottom" | |
619 // 2. mmap() the page in question | |
620 // | |
621 // Now alternate signal stack is gone, it's harder to use 2. For instance, | |
622 // if current sp is already near the lower end of page 101, and we need to | |
623 // call mmap() to map page 100, it is possible that part of the mmap() frame | |
624 // will be placed in page 100. When page 100 is mapped, it is zero-filled. | |
625 // That will destroy the mmap() frame and cause VM to crash. | |
626 // | |
627 // The following code works by adjusting sp first, then accessing the "bottom" | |
628 // page to force a page fault. Linux kernel will then automatically expand the | |
629 // stack mapping. | |
630 // | |
631 // _expand_stack_to() assumes its frame size is less than page size, which | |
632 // should always be true if the function is not inlined. | |
633 | |
634 #if __GNUC__ < 3 // gcc 2.x does not support noinline attribute | |
635 #define NOINLINE | |
636 #else | |
637 #define NOINLINE __attribute__ ((noinline)) | |
638 #endif | |
639 | |
640 static void _expand_stack_to(address bottom) NOINLINE; | |
641 | |
642 static void _expand_stack_to(address bottom) { | |
643 address sp; | |
644 size_t size; | |
645 volatile char *p; | |
646 | |
647 // Adjust bottom to point to the largest address within the same page, it | |
648 // gives us a one-page buffer if alloca() allocates slightly more memory. | |
649 bottom = (address)align_size_down((uintptr_t)bottom, os::Linux::page_size()); | |
650 bottom += os::Linux::page_size() - 1; | |
651 | |
652 // sp might be slightly above current stack pointer; if that's the case, we | |
653 // will alloca() a little more space than necessary, which is OK. Don't use | |
654 // os::current_stack_pointer(), as its result can be slightly below current | |
655 // stack pointer, causing us to not alloca enough to reach "bottom". | |
656 sp = (address)&sp; | |
657 | |
658 if (sp > bottom) { | |
659 size = sp - bottom; | |
660 p = (volatile char *)alloca(size); | |
661 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); | |
662 p[0] = '\0'; | |
663 } | |
664 } | |
665 | |
666 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) { | |
667 assert(t!=NULL, "just checking"); | |
668 assert(t->osthread()->expanding_stack(), "expand should be set"); | |
669 assert(t->stack_base() != NULL, "stack_base was not initialized"); | |
670 | |
671 if (addr < t->stack_base() && addr >= t->stack_yellow_zone_base()) { | |
672 sigset_t mask_all, old_sigset; | |
673 sigfillset(&mask_all); | |
674 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); | |
675 _expand_stack_to(addr); | |
676 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); | |
677 return true; | |
678 } | |
679 return false; | |
680 } | |
681 | |
682 ////////////////////////////////////////////////////////////////////////////// | |
683 // create new thread | |
684 | |
685 static address highest_vm_reserved_address(); | |
686 | |
687 // check if it's safe to start a new thread | |
688 static bool _thread_safety_check(Thread* thread) { | |
689 if (os::Linux::is_LinuxThreads() && !os::Linux::is_floating_stack()) { | |
690 // Fixed stack LinuxThreads (SuSE Linux/x86, and some versions of Redhat) | |
691 // Heap is mmap'ed at lower end of memory space. Thread stacks are | |
692 // allocated (MAP_FIXED) from high address space. Every thread stack | |
693 // occupies a fixed size slot (usually 2Mbytes, but user can change | |
694 // it to other values if they rebuild LinuxThreads). | |
695 // | |
696 // Problem with MAP_FIXED is that mmap() can still succeed even part of | |
697 // the memory region has already been mmap'ed. That means if we have too | |
698 // many threads and/or very large heap, eventually thread stack will | |
699 // collide with heap. | |
700 // | |
701 // Here we try to prevent heap/stack collision by comparing current | |
702 // stack bottom with the highest address that has been mmap'ed by JVM | |
703 // plus a safety margin for memory maps created by native code. | |
704 // | |
705 // This feature can be disabled by setting ThreadSafetyMargin to 0 | |
706 // | |
707 if (ThreadSafetyMargin > 0) { | |
708 address stack_bottom = os::current_stack_base() - os::current_stack_size(); | |
709 | |
710 // not safe if our stack extends below the safety margin | |
711 return stack_bottom - ThreadSafetyMargin >= highest_vm_reserved_address(); | |
712 } else { | |
713 return true; | |
714 } | |
715 } else { | |
716 // Floating stack LinuxThreads or NPTL: | |
717 // Unlike fixed stack LinuxThreads, thread stacks are not MAP_FIXED. When | |
718 // there's not enough space left, pthread_create() will fail. If we come | |
719 // here, that means enough space has been reserved for stack. | |
720 return true; | |
721 } | |
722 } | |
723 | |
724 // Thread start routine for all newly created threads | |
725 static void *java_start(Thread *thread) { | |
726 // Try to randomize the cache line index of hot stack frames. | |
727 // This helps when threads of the same stack traces evict each other's | |
728 // cache lines. The threads can be either from the same JVM instance, or | |
729 // from different JVM instances. The benefit is especially true for | |
730 // processors with hyperthreading technology. | |
731 static int counter = 0; | |
732 int pid = os::current_process_id(); | |
733 alloca(((pid ^ counter++) & 7) * 128); | |
734 | |
735 ThreadLocalStorage::set_thread(thread); | |
736 | |
737 OSThread* osthread = thread->osthread(); | |
738 Monitor* sync = osthread->startThread_lock(); | |
739 | |
740 // non floating stack LinuxThreads needs extra check, see above | |
741 if (!_thread_safety_check(thread)) { | |
742 // notify parent thread | |
743 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); | |
744 osthread->set_state(ZOMBIE); | |
745 sync->notify_all(); | |
746 return NULL; | |
747 } | |
748 | |
749 // thread_id is kernel thread id (similar to Solaris LWP id) | |
750 osthread->set_thread_id(os::Linux::gettid()); | |
751 | |
752 if (UseNUMA) { | |
753 int lgrp_id = os::numa_get_group_id(); | |
754 if (lgrp_id != -1) { | |
755 thread->set_lgrp_id(lgrp_id); | |
756 } | |
757 } | |
758 // initialize signal mask for this thread | |
759 os::Linux::hotspot_sigmask(thread); | |
760 | |
761 // initialize floating point control register | |
762 os::Linux::init_thread_fpu_state(); | |
763 | |
764 // handshaking with parent thread | |
765 { | |
766 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); | |
767 | |
768 // notify parent thread | |
769 osthread->set_state(INITIALIZED); | |
770 sync->notify_all(); | |
771 | |
772 // wait until os::start_thread() | |
773 while (osthread->get_state() == INITIALIZED) { | |
774 sync->wait(Mutex::_no_safepoint_check_flag); | |
775 } | |
776 } | |
777 | |
778 // call one more level start routine | |
779 thread->run(); | |
780 | |
781 return 0; | |
782 } | |
783 | |
784 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) { | |
785 assert(thread->osthread() == NULL, "caller responsible"); | |
786 | |
787 // Allocate the OSThread object | |
788 OSThread* osthread = new OSThread(NULL, NULL); | |
789 if (osthread == NULL) { | |
790 return false; | |
791 } | |
792 | |
793 // set the correct thread state | |
794 osthread->set_thread_type(thr_type); | |
795 | |
796 // Initial state is ALLOCATED but not INITIALIZED | |
797 osthread->set_state(ALLOCATED); | |
798 | |
799 thread->set_osthread(osthread); | |
800 | |
801 // init thread attributes | |
802 pthread_attr_t attr; | |
803 pthread_attr_init(&attr); | |
804 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); | |
805 | |
806 // stack size | |
807 if (os::Linux::supports_variable_stack_size()) { | |
808 // calculate stack size if it's not specified by caller | |
809 if (stack_size == 0) { | |
810 stack_size = os::Linux::default_stack_size(thr_type); | |
811 | |
812 switch (thr_type) { | |
813 case os::java_thread: | |
814 // Java threads use ThreadStackSize which default value can be changed with the flag -Xss | |
815 if (JavaThread::stack_size_at_create() > 0) stack_size = JavaThread::stack_size_at_create(); | |
816 break; | |
817 case os::compiler_thread: | |
818 if (CompilerThreadStackSize > 0) { | |
819 stack_size = (size_t)(CompilerThreadStackSize * K); | |
820 break; | |
821 } // else fall through: | |
822 // use VMThreadStackSize if CompilerThreadStackSize is not defined | |
823 case os::vm_thread: | |
824 case os::pgc_thread: | |
825 case os::cgc_thread: | |
826 case os::watcher_thread: | |
827 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K); | |
828 break; | |
829 } | |
830 } | |
831 | |
832 stack_size = MAX2(stack_size, os::Linux::min_stack_allowed); | |
833 pthread_attr_setstacksize(&attr, stack_size); | |
834 } else { | |
835 // let pthread_create() pick the default value. | |
836 } | |
837 | |
838 // glibc guard page | |
839 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); | |
840 | |
841 ThreadState state; | |
842 | |
843 { | |
844 // Serialize thread creation if we are running with fixed stack LinuxThreads | |
845 bool lock = os::Linux::is_LinuxThreads() && !os::Linux::is_floating_stack(); | |
846 if (lock) { | |
847 os::Linux::createThread_lock()->lock_without_safepoint_check(); | |
848 } | |
849 | |
850 pthread_t tid; | |
851 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread); | |
852 | |
853 pthread_attr_destroy(&attr); | |
854 | |
855 if (ret != 0) { | |
856 if (PrintMiscellaneous && (Verbose || WizardMode)) { | |
857 perror("pthread_create()"); | |
858 } | |
859 // Need to clean up stuff we've allocated so far | |
860 thread->set_osthread(NULL); | |
861 delete osthread; | |
862 if (lock) os::Linux::createThread_lock()->unlock(); | |
863 return false; | |
864 } | |
865 | |
866 // Store pthread info into the OSThread | |
867 osthread->set_pthread_id(tid); | |
868 | |
869 // Wait until child thread is either initialized or aborted | |
870 { | |
871 Monitor* sync_with_child = osthread->startThread_lock(); | |
872 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); | |
873 while ((state = osthread->get_state()) == ALLOCATED) { | |
874 sync_with_child->wait(Mutex::_no_safepoint_check_flag); | |
875 } | |
876 } | |
877 | |
878 if (lock) { | |
879 os::Linux::createThread_lock()->unlock(); | |
880 } | |
881 } | |
882 | |
883 // Aborted due to thread limit being reached | |
884 if (state == ZOMBIE) { | |
885 thread->set_osthread(NULL); | |
886 delete osthread; | |
887 return false; | |
888 } | |
889 | |
890 // The thread is returned suspended (in state INITIALIZED), | |
891 // and is started higher up in the call chain | |
892 assert(state == INITIALIZED, "race condition"); | |
893 return true; | |
894 } | |
895 | |
896 ///////////////////////////////////////////////////////////////////////////// | |
897 // attach existing thread | |
898 | |
899 // bootstrap the main thread | |
900 bool os::create_main_thread(JavaThread* thread) { | |
901 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread"); | |
902 return create_attached_thread(thread); | |
903 } | |
904 | |
905 bool os::create_attached_thread(JavaThread* thread) { | |
906 #ifdef ASSERT | |
907 thread->verify_not_published(); | |
908 #endif | |
909 | |
910 // Allocate the OSThread object | |
911 OSThread* osthread = new OSThread(NULL, NULL); | |
912 | |
913 if (osthread == NULL) { | |
914 return false; | |
915 } | |
916 | |
917 // Store pthread info into the OSThread | |
918 osthread->set_thread_id(os::Linux::gettid()); | |
919 osthread->set_pthread_id(::pthread_self()); | |
920 | |
921 // initialize floating point control register | |
922 os::Linux::init_thread_fpu_state(); | |
923 | |
924 // Initial thread state is RUNNABLE | |
925 osthread->set_state(RUNNABLE); | |
926 | |
927 thread->set_osthread(osthread); | |
928 | |
929 if (UseNUMA) { | |
930 int lgrp_id = os::numa_get_group_id(); | |
931 if (lgrp_id != -1) { | |
932 thread->set_lgrp_id(lgrp_id); | |
933 } | |
934 } | |
935 | |
936 if (os::Linux::is_initial_thread()) { | |
937 // If current thread is initial thread, its stack is mapped on demand, | |
938 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map | |
939 // the entire stack region to avoid SEGV in stack banging. | |
940 // It is also useful to get around the heap-stack-gap problem on SuSE | |
941 // kernel (see 4821821 for details). We first expand stack to the top | |
942 // of yellow zone, then enable stack yellow zone (order is significant, | |
943 // enabling yellow zone first will crash JVM on SuSE Linux), so there | |
944 // is no gap between the last two virtual memory regions. | |
945 | |
946 JavaThread *jt = (JavaThread *)thread; | |
947 address addr = jt->stack_yellow_zone_base(); | |
948 assert(addr != NULL, "initialization problem?"); | |
949 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); | |
950 | |
951 osthread->set_expanding_stack(); | |
952 os::Linux::manually_expand_stack(jt, addr); | |
953 osthread->clear_expanding_stack(); | |
954 } | |
955 | |
956 // initialize signal mask for this thread | |
957 // and save the caller's signal mask | |
958 os::Linux::hotspot_sigmask(thread); | |
959 | |
960 return true; | |
961 } | |
962 | |
963 void os::pd_start_thread(Thread* thread) { | |
964 OSThread * osthread = thread->osthread(); | |
965 assert(osthread->get_state() != INITIALIZED, "just checking"); | |
966 Monitor* sync_with_child = osthread->startThread_lock(); | |
967 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); | |
968 sync_with_child->notify(); | |
969 } | |
970 | |
971 // Free Linux resources related to the OSThread | |
972 void os::free_thread(OSThread* osthread) { | |
973 assert(osthread != NULL, "osthread not set"); | |
974 | |
975 if (Thread::current()->osthread() == osthread) { | |
976 // Restore caller's signal mask | |
977 sigset_t sigmask = osthread->caller_sigmask(); | |
978 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); | |
979 } | |
980 | |
981 delete osthread; | |
982 } | |
983 | |
984 ////////////////////////////////////////////////////////////////////////////// | |
985 // thread local storage | |
986 | |
987 int os::allocate_thread_local_storage() { | |
988 pthread_key_t key; | |
989 int rslt = pthread_key_create(&key, NULL); | |
990 assert(rslt == 0, "cannot allocate thread local storage"); | |
991 return (int)key; | |
992 } | |
993 | |
994 // Note: This is currently not used by VM, as we don't destroy TLS key | |
995 // on VM exit. | |
996 void os::free_thread_local_storage(int index) { | |
997 int rslt = pthread_key_delete((pthread_key_t)index); | |
998 assert(rslt == 0, "invalid index"); | |
999 } | |
1000 | |
1001 void os::thread_local_storage_at_put(int index, void* value) { | |
1002 int rslt = pthread_setspecific((pthread_key_t)index, value); | |
1003 assert(rslt == 0, "pthread_setspecific failed"); | |
1004 } | |
1005 | |
1006 extern "C" Thread* get_thread() { | |
1007 return ThreadLocalStorage::thread(); | |
1008 } | |
1009 | |
1010 ////////////////////////////////////////////////////////////////////////////// | |
1011 // initial thread | |
1012 | |
1013 // Check if current thread is the initial thread, similar to Solaris thr_main. | |
1014 bool os::Linux::is_initial_thread(void) { | |
1015 char dummy; | |
1016 // If called before init complete, thread stack bottom will be null. | |
1017 // Can be called if fatal error occurs before initialization. | |
1018 if (initial_thread_stack_bottom() == NULL) return false; | |
1019 assert(initial_thread_stack_bottom() != NULL && | |
1020 initial_thread_stack_size() != 0, | |
1021 "os::init did not locate initial thread's stack region"); | |
1022 if ((address)&dummy >= initial_thread_stack_bottom() && | |
1023 (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size()) | |
1024 return true; | |
1025 else return false; | |
1026 } | |
1027 | |
1028 // Find the virtual memory area that contains addr | |
1029 static bool find_vma(address addr, address* vma_low, address* vma_high) { | |
1030 FILE *fp = fopen("/proc/self/maps", "r"); | |
1031 if (fp) { | |
1032 address low, high; | |
1033 while (!feof(fp)) { | |
1034 if (fscanf(fp, "%p-%p", &low, &high) == 2) { | |
1035 if (low <= addr && addr < high) { | |
1036 if (vma_low) *vma_low = low; | |
1037 if (vma_high) *vma_high = high; | |
1038 fclose (fp); | |
1039 return true; | |
1040 } | |
1041 } | |
1042 for (;;) { | |
1043 int ch = fgetc(fp); | |
1044 if (ch == EOF || ch == (int)'\n') break; | |
1045 } | |
1046 } | |
1047 fclose(fp); | |
1048 } | |
1049 return false; | |
1050 } | |
1051 | |
1052 // Locate initial thread stack. This special handling of initial thread stack | |
1053 // is needed because pthread_getattr_np() on most (all?) Linux distros returns | |
1054 // bogus value for initial thread. | |
1055 void os::Linux::capture_initial_stack(size_t max_size) { | |
1056 // stack size is the easy part, get it from RLIMIT_STACK | |
1057 size_t stack_size; | |
1058 struct rlimit rlim; | |
1059 getrlimit(RLIMIT_STACK, &rlim); | |
1060 stack_size = rlim.rlim_cur; | |
1061 | |
1062 // 6308388: a bug in ld.so will relocate its own .data section to the | |
1063 // lower end of primordial stack; reduce ulimit -s value a little bit | |
1064 // so we won't install guard page on ld.so's data section. | |
1065 stack_size -= 2 * page_size(); | |
1066 | |
1067 // 4441425: avoid crash with "unlimited" stack size on SuSE 7.1 or Redhat | |
1068 // 7.1, in both cases we will get 2G in return value. | |
1069 // 4466587: glibc 2.2.x compiled w/o "--enable-kernel=2.4.0" (RH 7.0, | |
1070 // SuSE 7.2, Debian) can not handle alternate signal stack correctly | |
1071 // for initial thread if its stack size exceeds 6M. Cap it at 2M, | |
1072 // in case other parts in glibc still assumes 2M max stack size. | |
1073 // FIXME: alt signal stack is gone, maybe we can relax this constraint? | |
1074 #ifndef IA64 | |
1075 if (stack_size > 2 * K * K) stack_size = 2 * K * K; | |
1076 #else | |
1077 // Problem still exists RH7.2 (IA64 anyway) but 2MB is a little small | |
1078 if (stack_size > 4 * K * K) stack_size = 4 * K * K; | |
1079 #endif | |
1080 | |
1081 // Try to figure out where the stack base (top) is. This is harder. | |
1082 // | |
1083 // When an application is started, glibc saves the initial stack pointer in | |
1084 // a global variable "__libc_stack_end", which is then used by system | |
1085 // libraries. __libc_stack_end should be pretty close to stack top. The | |
1086 // variable is available since the very early days. However, because it is | |
1087 // a private interface, it could disappear in the future. | |
1088 // | |
1089 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar | |
1090 // to __libc_stack_end, it is very close to stack top, but isn't the real | |
1091 // stack top. Note that /proc may not exist if VM is running as a chroot | |
1092 // program, so reading /proc/<pid>/stat could fail. Also the contents of | |
1093 // /proc/<pid>/stat could change in the future (though unlikely). | |
1094 // | |
1095 // We try __libc_stack_end first. If that doesn't work, look for | |
1096 // /proc/<pid>/stat. If neither of them works, we use current stack pointer | |
1097 // as a hint, which should work well in most cases. | |
1098 | |
1099 uintptr_t stack_start; | |
1100 | |
1101 // try __libc_stack_end first | |
1102 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end"); | |
1103 if (p && *p) { | |
1104 stack_start = *p; | |
1105 } else { | |
1106 // see if we can get the start_stack field from /proc/self/stat | |
1107 FILE *fp; | |
1108 int pid; | |
1109 char state; | |
1110 int ppid; | |
1111 int pgrp; | |
1112 int session; | |
1113 int nr; | |
1114 int tpgrp; | |
1115 unsigned long flags; | |
1116 unsigned long minflt; | |
1117 unsigned long cminflt; | |
1118 unsigned long majflt; | |
1119 unsigned long cmajflt; | |
1120 unsigned long utime; | |
1121 unsigned long stime; | |
1122 long cutime; | |
1123 long cstime; | |
1124 long prio; | |
1125 long nice; | |
1126 long junk; | |
1127 long it_real; | |
1128 uintptr_t start; | |
1129 uintptr_t vsize; | |
1130 uintptr_t rss; | |
1131 unsigned long rsslim; | |
1132 uintptr_t scodes; | |
1133 uintptr_t ecode; | |
1134 int i; | |
1135 | |
1136 // Figure what the primordial thread stack base is. Code is inspired | |
1137 // by email from Hans Boehm. /proc/self/stat begins with current pid, | |
1138 // followed by command name surrounded by parentheses, state, etc. | |
1139 char stat[2048]; | |
1140 int statlen; | |
1141 | |
1142 fp = fopen("/proc/self/stat", "r"); | |
1143 if (fp) { | |
1144 statlen = fread(stat, 1, 2047, fp); | |
1145 stat[statlen] = '\0'; | |
1146 fclose(fp); | |
1147 | |
1148 // Skip pid and the command string. Note that we could be dealing with | |
1149 // weird command names, e.g. user could decide to rename java launcher | |
1150 // to "java 1.4.2 :)", then the stat file would look like | |
1151 // 1234 (java 1.4.2 :)) R ... ... | |
1152 // We don't really need to know the command string, just find the last | |
1153 // occurrence of ")" and then start parsing from there. See bug 4726580. | |
1154 char * s = strrchr(stat, ')'); | |
1155 | |
1156 i = 0; | |
1157 if (s) { | |
1158 // Skip blank chars | |
1159 do s++; while (isspace(*s)); | |
1160 | |
1161 /* 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 */ | |
1162 /* 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 */ | |
1163 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", | |
1164 &state, /* 3 %c */ | |
1165 &ppid, /* 4 %d */ | |
1166 &pgrp, /* 5 %d */ | |
1167 &session, /* 6 %d */ | |
1168 &nr, /* 7 %d */ | |
1169 &tpgrp, /* 8 %d */ | |
1170 &flags, /* 9 %lu */ | |
1171 &minflt, /* 10 %lu */ | |
1172 &cminflt, /* 11 %lu */ | |
1173 &majflt, /* 12 %lu */ | |
1174 &cmajflt, /* 13 %lu */ | |
1175 &utime, /* 14 %lu */ | |
1176 &stime, /* 15 %lu */ | |
1177 &cutime, /* 16 %ld */ | |
1178 &cstime, /* 17 %ld */ | |
1179 &prio, /* 18 %ld */ | |
1180 &nice, /* 19 %ld */ | |
1181 &junk, /* 20 %ld */ | |
1182 &it_real, /* 21 %ld */ | |
1183 &start, /* 22 %lu */ | |
1184 &vsize, /* 23 %lu */ | |
1185 &rss, /* 24 %ld */ | |
1186 &rsslim, /* 25 %lu */ | |
1187 &scodes, /* 26 %lu */ | |
1188 &ecode, /* 27 %lu */ | |
1189 &stack_start); /* 28 %lu */ | |
1190 } | |
1191 | |
1192 if (i != 28 - 2) { | |
1193 assert(false, "Bad conversion from /proc/self/stat"); | |
1194 // product mode - assume we are the initial thread, good luck in the | |
1195 // embedded case. | |
1196 warning("Can't detect initial thread stack location - bad conversion"); | |
1197 stack_start = (uintptr_t) &rlim; | |
1198 } | |
1199 } else { | |
1200 // For some reason we can't open /proc/self/stat (for example, running on | |
1201 // FreeBSD with a Linux emulator, or inside chroot), this should work for | |
1202 // most cases, so don't abort: | |
1203 warning("Can't detect initial thread stack location - no /proc/self/stat"); | |
1204 stack_start = (uintptr_t) &rlim; | |
1205 } | |
1206 } | |
1207 | |
1208 // Now we have a pointer (stack_start) very close to the stack top, the | |
1209 // next thing to do is to figure out the exact location of stack top. We | |
1210 // can find out the virtual memory area that contains stack_start by | |
1211 // reading /proc/self/maps, it should be the last vma in /proc/self/maps, | |
1212 // and its upper limit is the real stack top. (again, this would fail if | |
1213 // running inside chroot, because /proc may not exist.) | |
1214 | |
1215 uintptr_t stack_top; | |
1216 address low, high; | |
1217 if (find_vma((address)stack_start, &low, &high)) { | |
1218 // success, "high" is the true stack top. (ignore "low", because initial | |
1219 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.) | |
1220 stack_top = (uintptr_t)high; | |
1221 } else { | |
1222 // failed, likely because /proc/self/maps does not exist | |
1223 warning("Can't detect initial thread stack location - find_vma failed"); | |
1224 // best effort: stack_start is normally within a few pages below the real | |
1225 // stack top, use it as stack top, and reduce stack size so we won't put | |
1226 // guard page outside stack. | |
1227 stack_top = stack_start; | |
1228 stack_size -= 16 * page_size(); | |
1229 } | |
1230 | |
1231 // stack_top could be partially down the page so align it | |
1232 stack_top = align_size_up(stack_top, page_size()); | |
1233 | |
1234 if (max_size && stack_size > max_size) { | |
1235 _initial_thread_stack_size = max_size; | |
1236 } else { | |
1237 _initial_thread_stack_size = stack_size; | |
1238 } | |
1239 | |
1240 _initial_thread_stack_size = align_size_down(_initial_thread_stack_size, page_size()); | |
1241 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; | |
1242 } | |
1243 | |
1244 //////////////////////////////////////////////////////////////////////////////// | |
1245 // time support | |
1246 | |
1247 // Time since start-up in seconds to a fine granularity. | |
1248 // Used by VMSelfDestructTimer and the MemProfiler. | |
1249 double os::elapsedTime() { | |
1250 | |
1251 return (double)(os::elapsed_counter()) * 0.000001; | |
1252 } | |
1253 | |
1254 jlong os::elapsed_counter() { | |
1255 timeval time; | |
1256 int status = gettimeofday(&time, NULL); | |
1257 return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count; | |
1258 } | |
1259 | |
1260 jlong os::elapsed_frequency() { | |
1261 return (1000 * 1000); | |
1262 } | |
1263 | |
61 | 1264 jlong os::javaTimeMillis() { |
0 | 1265 timeval time; |
1266 int status = gettimeofday(&time, NULL); | |
1267 assert(status != -1, "linux error"); | |
1268 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); | |
1269 } | |
1270 | |
1271 #ifndef CLOCK_MONOTONIC | |
1272 #define CLOCK_MONOTONIC (1) | |
1273 #endif | |
1274 | |
1275 void os::Linux::clock_init() { | |
1276 // we do dlopen's in this particular order due to bug in linux | |
1277 // dynamical loader (see 6348968) leading to crash on exit | |
1278 void* handle = dlopen("librt.so.1", RTLD_LAZY); | |
1279 if (handle == NULL) { | |
1280 handle = dlopen("librt.so", RTLD_LAZY); | |
1281 } | |
1282 | |
1283 if (handle) { | |
1284 int (*clock_getres_func)(clockid_t, struct timespec*) = | |
1285 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres"); | |
1286 int (*clock_gettime_func)(clockid_t, struct timespec*) = | |
1287 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime"); | |
1288 if (clock_getres_func && clock_gettime_func) { | |
1289 // See if monotonic clock is supported by the kernel. Note that some | |
1290 // early implementations simply return kernel jiffies (updated every | |
1291 // 1/100 or 1/1000 second). It would be bad to use such a low res clock | |
1292 // for nano time (though the monotonic property is still nice to have). | |
1293 // It's fixed in newer kernels, however clock_getres() still returns | |
1294 // 1/HZ. We check if clock_getres() works, but will ignore its reported | |
1295 // resolution for now. Hopefully as people move to new kernels, this | |
1296 // won't be a problem. | |
1297 struct timespec res; | |
1298 struct timespec tp; | |
1299 if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 && | |
1300 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) { | |
1301 // yes, monotonic clock is supported | |
1302 _clock_gettime = clock_gettime_func; | |
1303 } else { | |
1304 // close librt if there is no monotonic clock | |
1305 dlclose(handle); | |
1306 } | |
1307 } | |
1308 } | |
1309 } | |
1310 | |
1311 #ifndef SYS_clock_getres | |
1312 | |
1313 #if defined(IA32) || defined(AMD64) | |
1314 #define SYS_clock_getres IA32_ONLY(266) AMD64_ONLY(229) | |
1315 #else | |
1316 #error Value of SYS_clock_getres not known on this platform | |
1317 #endif | |
1318 | |
1319 #endif | |
1320 | |
1321 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) | |
1322 | |
1323 void os::Linux::fast_thread_clock_init() { | |
1324 if (!UseLinuxPosixThreadCPUClocks) { | |
1325 return; | |
1326 } | |
1327 clockid_t clockid; | |
1328 struct timespec tp; | |
1329 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) = | |
1330 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid"); | |
1331 | |
1332 // Switch to using fast clocks for thread cpu time if | |
1333 // the sys_clock_getres() returns 0 error code. | |
1334 // Note, that some kernels may support the current thread | |
1335 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks | |
1336 // returned by the pthread_getcpuclockid(). | |
1337 // If the fast Posix clocks are supported then the sys_clock_getres() | |
1338 // must return at least tp.tv_sec == 0 which means a resolution | |
1339 // better than 1 sec. This is extra check for reliability. | |
1340 | |
1341 if(pthread_getcpuclockid_func && | |
1342 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 && | |
1343 sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) { | |
1344 | |
1345 _supports_fast_thread_cpu_time = true; | |
1346 _pthread_getcpuclockid = pthread_getcpuclockid_func; | |
1347 } | |
1348 } | |
1349 | |
1350 jlong os::javaTimeNanos() { | |
1351 if (Linux::supports_monotonic_clock()) { | |
1352 struct timespec tp; | |
1353 int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp); | |
1354 assert(status == 0, "gettime error"); | |
1355 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); | |
1356 return result; | |
1357 } else { | |
1358 timeval time; | |
1359 int status = gettimeofday(&time, NULL); | |
1360 assert(status != -1, "linux error"); | |
1361 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); | |
1362 return 1000 * usecs; | |
1363 } | |
1364 } | |
1365 | |
1366 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { | |
1367 if (Linux::supports_monotonic_clock()) { | |
1368 info_ptr->max_value = ALL_64_BITS; | |
1369 | |
1370 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past | |
1371 info_ptr->may_skip_backward = false; // not subject to resetting or drifting | |
1372 info_ptr->may_skip_forward = false; // not subject to resetting or drifting | |
1373 } else { | |
1374 // gettimeofday - based on time in seconds since the Epoch thus does not wrap | |
1375 info_ptr->max_value = ALL_64_BITS; | |
1376 | |
1377 // gettimeofday is a real time clock so it skips | |
1378 info_ptr->may_skip_backward = true; | |
1379 info_ptr->may_skip_forward = true; | |
1380 } | |
1381 | |
1382 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time | |
1383 } | |
1384 | |
1385 // Return the real, user, and system times in seconds from an | |
1386 // arbitrary fixed point in the past. | |
1387 bool os::getTimesSecs(double* process_real_time, | |
1388 double* process_user_time, | |
1389 double* process_system_time) { | |
1390 struct tms ticks; | |
1391 clock_t real_ticks = times(&ticks); | |
1392 | |
1393 if (real_ticks == (clock_t) (-1)) { | |
1394 return false; | |
1395 } else { | |
1396 double ticks_per_second = (double) clock_tics_per_sec; | |
1397 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; | |
1398 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; | |
1399 *process_real_time = ((double) real_ticks) / ticks_per_second; | |
1400 | |
1401 return true; | |
1402 } | |
1403 } | |
1404 | |
1405 | |
1406 char * os::local_time_string(char *buf, size_t buflen) { | |
1407 struct tm t; | |
1408 time_t long_time; | |
1409 time(&long_time); | |
1410 localtime_r(&long_time, &t); | |
1411 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", | |
1412 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, | |
1413 t.tm_hour, t.tm_min, t.tm_sec); | |
1414 return buf; | |
1415 } | |
1416 | |
1417 //////////////////////////////////////////////////////////////////////////////// | |
1418 // runtime exit support | |
1419 | |
1420 // Note: os::shutdown() might be called very early during initialization, or | |
1421 // called from signal handler. Before adding something to os::shutdown(), make | |
1422 // sure it is async-safe and can handle partially initialized VM. | |
1423 void os::shutdown() { | |
1424 | |
1425 // allow PerfMemory to attempt cleanup of any persistent resources | |
1426 perfMemory_exit(); | |
1427 | |
1428 // needs to remove object in file system | |
1429 AttachListener::abort(); | |
1430 | |
1431 // flush buffered output, finish log files | |
1432 ostream_abort(); | |
1433 | |
1434 // Check for abort hook | |
1435 abort_hook_t abort_hook = Arguments::abort_hook(); | |
1436 if (abort_hook != NULL) { | |
1437 abort_hook(); | |
1438 } | |
1439 | |
1440 } | |
1441 | |
1442 // Note: os::abort() might be called very early during initialization, or | |
1443 // called from signal handler. Before adding something to os::abort(), make | |
1444 // sure it is async-safe and can handle partially initialized VM. | |
1445 void os::abort(bool dump_core) { | |
1446 os::shutdown(); | |
1447 if (dump_core) { | |
1448 #ifndef PRODUCT | |
1449 fdStream out(defaultStream::output_fd()); | |
1450 out.print_raw("Current thread is "); | |
1451 char buf[16]; | |
1452 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); | |
1453 out.print_raw_cr(buf); | |
1454 out.print_raw_cr("Dumping core ..."); | |
1455 #endif | |
1456 ::abort(); // dump core | |
1457 } | |
1458 | |
1459 ::exit(1); | |
1460 } | |
1461 | |
1462 // Die immediately, no exit hook, no abort hook, no cleanup. | |
1463 void os::die() { | |
1464 // _exit() on LinuxThreads only kills current thread | |
1465 ::abort(); | |
1466 } | |
1467 | |
1468 // unused on linux for now. | |
1469 void os::set_error_file(const char *logfile) {} | |
1470 | |
1471 intx os::current_thread_id() { return (intx)pthread_self(); } | |
1472 int os::current_process_id() { | |
1473 | |
1474 // Under the old linux thread library, linux gives each thread | |
1475 // its own process id. Because of this each thread will return | |
1476 // a different pid if this method were to return the result | |
1477 // of getpid(2). Linux provides no api that returns the pid | |
1478 // of the launcher thread for the vm. This implementation | |
1479 // returns a unique pid, the pid of the launcher thread | |
1480 // that starts the vm 'process'. | |
1481 | |
1482 // Under the NPTL, getpid() returns the same pid as the | |
1483 // launcher thread rather than a unique pid per thread. | |
1484 // Use gettid() if you want the old pre NPTL behaviour. | |
1485 | |
1486 // if you are looking for the result of a call to getpid() that | |
1487 // returns a unique pid for the calling thread, then look at the | |
1488 // OSThread::thread_id() method in osThread_linux.hpp file | |
1489 | |
1490 return (int)(_initial_pid ? _initial_pid : getpid()); | |
1491 } | |
1492 | |
1493 // DLL functions | |
1494 | |
1495 const char* os::dll_file_extension() { return ".so"; } | |
1496 | |
1497 const char* os::get_temp_directory() { return "/tmp/"; } | |
1498 | |
242 | 1499 void os::dll_build_name( |
1500 char* buffer, size_t buflen, const char* pname, const char* fname) { | |
1501 // copied from libhpi | |
1502 const size_t pnamelen = pname ? strlen(pname) : 0; | |
1503 | |
1504 /* Quietly truncate on buffer overflow. Should be an error. */ | |
1505 if (pnamelen + strlen(fname) + 10 > (size_t) buflen) { | |
1506 *buffer = '\0'; | |
1507 return; | |
1508 } | |
1509 | |
1510 if (pnamelen == 0) { | |
1511 sprintf(buffer, "lib%s.so", fname); | |
1512 } else { | |
1513 sprintf(buffer, "%s/lib%s.so", pname, fname); | |
1514 } | |
1515 } | |
1516 | |
0 | 1517 const char* os::get_current_directory(char *buf, int buflen) { |
1518 return getcwd(buf, buflen); | |
1519 } | |
1520 | |
1521 // check if addr is inside libjvm[_g].so | |
1522 bool os::address_is_in_vm(address addr) { | |
1523 static address libjvm_base_addr; | |
1524 Dl_info dlinfo; | |
1525 | |
1526 if (libjvm_base_addr == NULL) { | |
1527 dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo); | |
1528 libjvm_base_addr = (address)dlinfo.dli_fbase; | |
1529 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); | |
1530 } | |
1531 | |
1532 if (dladdr((void *)addr, &dlinfo)) { | |
1533 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; | |
1534 } | |
1535 | |
1536 return false; | |
1537 } | |
1538 | |
1539 bool os::dll_address_to_function_name(address addr, char *buf, | |
1540 int buflen, int *offset) { | |
1541 Dl_info dlinfo; | |
1542 | |
1543 if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) { | |
1544 if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); | |
1545 if (offset) *offset = addr - (address)dlinfo.dli_saddr; | |
1546 return true; | |
1547 } else { | |
1548 if (buf) buf[0] = '\0'; | |
1549 if (offset) *offset = -1; | |
1550 return false; | |
1551 } | |
1552 } | |
1553 | |
1554 struct _address_to_library_name { | |
1555 address addr; // input : memory address | |
1556 size_t buflen; // size of fname | |
1557 char* fname; // output: library name | |
1558 address base; // library base addr | |
1559 }; | |
1560 | |
1561 static int address_to_library_name_callback(struct dl_phdr_info *info, | |
1562 size_t size, void *data) { | |
1563 int i; | |
1564 bool found = false; | |
1565 address libbase = NULL; | |
1566 struct _address_to_library_name * d = (struct _address_to_library_name *)data; | |
1567 | |
1568 // iterate through all loadable segments | |
1569 for (i = 0; i < info->dlpi_phnum; i++) { | |
1570 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); | |
1571 if (info->dlpi_phdr[i].p_type == PT_LOAD) { | |
1572 // base address of a library is the lowest address of its loaded | |
1573 // segments. | |
1574 if (libbase == NULL || libbase > segbase) { | |
1575 libbase = segbase; | |
1576 } | |
1577 // see if 'addr' is within current segment | |
1578 if (segbase <= d->addr && | |
1579 d->addr < segbase + info->dlpi_phdr[i].p_memsz) { | |
1580 found = true; | |
1581 } | |
1582 } | |
1583 } | |
1584 | |
1585 // dlpi_name is NULL or empty if the ELF file is executable, return 0 | |
1586 // so dll_address_to_library_name() can fall through to use dladdr() which | |
1587 // can figure out executable name from argv[0]. | |
1588 if (found && info->dlpi_name && info->dlpi_name[0]) { | |
1589 d->base = libbase; | |
1590 if (d->fname) { | |
1591 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); | |
1592 } | |
1593 return 1; | |
1594 } | |
1595 return 0; | |
1596 } | |
1597 | |
1598 bool os::dll_address_to_library_name(address addr, char* buf, | |
1599 int buflen, int* offset) { | |
1600 Dl_info dlinfo; | |
1601 struct _address_to_library_name data; | |
1602 | |
1603 // There is a bug in old glibc dladdr() implementation that it could resolve | |
1604 // to wrong library name if the .so file has a base address != NULL. Here | |
1605 // we iterate through the program headers of all loaded libraries to find | |
1606 // out which library 'addr' really belongs to. This workaround can be | |
1607 // removed once the minimum requirement for glibc is moved to 2.3.x. | |
1608 data.addr = addr; | |
1609 data.fname = buf; | |
1610 data.buflen = buflen; | |
1611 data.base = NULL; | |
1612 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); | |
1613 | |
1614 if (rslt) { | |
1615 // buf already contains library name | |
1616 if (offset) *offset = addr - data.base; | |
1617 return true; | |
1618 } else if (dladdr((void*)addr, &dlinfo)){ | |
1619 if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); | |
1620 if (offset) *offset = addr - (address)dlinfo.dli_fbase; | |
1621 return true; | |
1622 } else { | |
1623 if (buf) buf[0] = '\0'; | |
1624 if (offset) *offset = -1; | |
1625 return false; | |
1626 } | |
1627 } | |
1628 | |
1629 // Loads .dll/.so and | |
1630 // in case of error it checks if .dll/.so was built for the | |
1631 // same architecture as Hotspot is running on | |
1632 | |
1633 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) | |
1634 { | |
1635 void * result= ::dlopen(filename, RTLD_LAZY); | |
1636 if (result != NULL) { | |
1637 // Successful loading | |
1638 return result; | |
1639 } | |
1640 | |
1641 Elf32_Ehdr elf_head; | |
1642 | |
1643 // Read system error message into ebuf | |
1644 // It may or may not be overwritten below | |
1645 ::strncpy(ebuf, ::dlerror(), ebuflen-1); | |
1646 ebuf[ebuflen-1]='\0'; | |
1647 int diag_msg_max_length=ebuflen-strlen(ebuf); | |
1648 char* diag_msg_buf=ebuf+strlen(ebuf); | |
1649 | |
1650 if (diag_msg_max_length==0) { | |
1651 // No more space in ebuf for additional diagnostics message | |
1652 return NULL; | |
1653 } | |
1654 | |
1655 | |
1656 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); | |
1657 | |
1658 if (file_descriptor < 0) { | |
1659 // Can't open library, report dlerror() message | |
1660 return NULL; | |
1661 } | |
1662 | |
1663 bool failed_to_read_elf_head= | |
1664 (sizeof(elf_head)!= | |
1665 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ; | |
1666 | |
1667 ::close(file_descriptor); | |
1668 if (failed_to_read_elf_head) { | |
1669 // file i/o error - report dlerror() msg | |
1670 return NULL; | |
1671 } | |
1672 | |
1673 typedef struct { | |
1674 Elf32_Half code; // Actual value as defined in elf.h | |
1675 Elf32_Half compat_class; // Compatibility of archs at VM's sense | |
1676 char elf_class; // 32 or 64 bit | |
1677 char endianess; // MSB or LSB | |
1678 char* name; // String representation | |
1679 } arch_t; | |
1680 | |
1681 #ifndef EM_486 | |
1682 #define EM_486 6 /* Intel 80486 */ | |
1683 #endif | |
1684 | |
1685 static const arch_t arch_array[]={ | |
1686 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, | |
1687 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, | |
1688 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, | |
1689 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, | |
1690 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, | |
1691 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, | |
1692 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, | |
1693 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, | |
1694 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"} | |
1695 }; | |
1696 | |
1697 #if (defined IA32) | |
1698 static Elf32_Half running_arch_code=EM_386; | |
1699 #elif (defined AMD64) | |
1700 static Elf32_Half running_arch_code=EM_X86_64; | |
1701 #elif (defined IA64) | |
1702 static Elf32_Half running_arch_code=EM_IA_64; | |
1703 #elif (defined __sparc) && (defined _LP64) | |
1704 static Elf32_Half running_arch_code=EM_SPARCV9; | |
1705 #elif (defined __sparc) && (!defined _LP64) | |
1706 static Elf32_Half running_arch_code=EM_SPARC; | |
1707 #elif (defined __powerpc64__) | |
1708 static Elf32_Half running_arch_code=EM_PPC64; | |
1709 #elif (defined __powerpc__) | |
1710 static Elf32_Half running_arch_code=EM_PPC; | |
1711 #else | |
1712 #error Method os::dll_load requires that one of following is defined:\ | |
1713 IA32, AMD64, IA64, __sparc, __powerpc__ | |
1714 #endif | |
1715 | |
1716 // Identify compatability class for VM's architecture and library's architecture | |
1717 // Obtain string descriptions for architectures | |
1718 | |
1719 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; | |
1720 int running_arch_index=-1; | |
1721 | |
1722 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) { | |
1723 if (running_arch_code == arch_array[i].code) { | |
1724 running_arch_index = i; | |
1725 } | |
1726 if (lib_arch.code == arch_array[i].code) { | |
1727 lib_arch.compat_class = arch_array[i].compat_class; | |
1728 lib_arch.name = arch_array[i].name; | |
1729 } | |
1730 } | |
1731 | |
1732 assert(running_arch_index != -1, | |
1733 "Didn't find running architecture code (running_arch_code) in arch_array"); | |
1734 if (running_arch_index == -1) { | |
1735 // Even though running architecture detection failed | |
1736 // we may still continue with reporting dlerror() message | |
1737 return NULL; | |
1738 } | |
1739 | |
1740 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { | |
1741 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); | |
1742 return NULL; | |
1743 } | |
1744 | |
1745 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { | |
1746 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); | |
1747 return NULL; | |
1748 } | |
1749 | |
1750 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { | |
1751 if ( lib_arch.name!=NULL ) { | |
1752 ::snprintf(diag_msg_buf, diag_msg_max_length-1, | |
1753 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", | |
1754 lib_arch.name, arch_array[running_arch_index].name); | |
1755 } else { | |
1756 ::snprintf(diag_msg_buf, diag_msg_max_length-1, | |
1757 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", | |
1758 lib_arch.code, | |
1759 arch_array[running_arch_index].name); | |
1760 } | |
1761 } | |
1762 | |
1763 return NULL; | |
1764 } | |
1765 | |
242 | 1766 /* |
1767 * glibc-2.0 libdl is not MT safe. If you are building with any glibc, | |
1768 * chances are you might want to run the generated bits against glibc-2.0 | |
1769 * libdl.so, so always use locking for any version of glibc. | |
1770 */ | |
1771 void* os::dll_lookup(void* handle, const char* name) { | |
1772 pthread_mutex_lock(&dl_mutex); | |
1773 void* res = dlsym(handle, name); | |
1774 pthread_mutex_unlock(&dl_mutex); | |
1775 return res; | |
1776 } | |
0 | 1777 |
1778 | |
1779 bool _print_ascii_file(const char* filename, outputStream* st) { | |
1780 int fd = open(filename, O_RDONLY); | |
1781 if (fd == -1) { | |
1782 return false; | |
1783 } | |
1784 | |
1785 char buf[32]; | |
1786 int bytes; | |
1787 while ((bytes = read(fd, buf, sizeof(buf))) > 0) { | |
1788 st->print_raw(buf, bytes); | |
1789 } | |
1790 | |
1791 close(fd); | |
1792 | |
1793 return true; | |
1794 } | |
1795 | |
1796 void os::print_dll_info(outputStream *st) { | |
1797 st->print_cr("Dynamic libraries:"); | |
1798 | |
1799 char fname[32]; | |
1800 pid_t pid = os::Linux::gettid(); | |
1801 | |
1802 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); | |
1803 | |
1804 if (!_print_ascii_file(fname, st)) { | |
1805 st->print("Can not get library information for pid = %d\n", pid); | |
1806 } | |
1807 } | |
1808 | |
1809 | |
1810 void os::print_os_info(outputStream* st) { | |
1811 st->print("OS:"); | |
1812 | |
1813 // Try to identify popular distros. | |
1814 // Most Linux distributions have /etc/XXX-release file, which contains | |
1815 // the OS version string. Some have more than one /etc/XXX-release file | |
1816 // (e.g. Mandrake has both /etc/mandrake-release and /etc/redhat-release.), | |
1817 // so the order is important. | |
1818 if (!_print_ascii_file("/etc/mandrake-release", st) && | |
1819 !_print_ascii_file("/etc/sun-release", st) && | |
1820 !_print_ascii_file("/etc/redhat-release", st) && | |
1821 !_print_ascii_file("/etc/SuSE-release", st) && | |
1822 !_print_ascii_file("/etc/turbolinux-release", st) && | |
1823 !_print_ascii_file("/etc/gentoo-release", st) && | |
1824 !_print_ascii_file("/etc/debian_version", st)) { | |
1825 st->print("Linux"); | |
1826 } | |
1827 st->cr(); | |
1828 | |
1829 // kernel | |
1830 st->print("uname:"); | |
1831 struct utsname name; | |
1832 uname(&name); | |
1833 st->print(name.sysname); st->print(" "); | |
1834 st->print(name.release); st->print(" "); | |
1835 st->print(name.version); st->print(" "); | |
1836 st->print(name.machine); | |
1837 st->cr(); | |
1838 | |
1839 // Print warning if unsafe chroot environment detected | |
1840 if (unsafe_chroot_detected) { | |
1841 st->print("WARNING!! "); | |
1842 st->print_cr(unstable_chroot_error); | |
1843 } | |
1844 | |
1845 // libc, pthread | |
1846 st->print("libc:"); | |
1847 st->print(os::Linux::glibc_version()); st->print(" "); | |
1848 st->print(os::Linux::libpthread_version()); st->print(" "); | |
1849 if (os::Linux::is_LinuxThreads()) { | |
1850 st->print("(%s stack)", os::Linux::is_floating_stack() ? "floating" : "fixed"); | |
1851 } | |
1852 st->cr(); | |
1853 | |
1854 // rlimit | |
1855 st->print("rlimit:"); | |
1856 struct rlimit rlim; | |
1857 | |
1858 st->print(" STACK "); | |
1859 getrlimit(RLIMIT_STACK, &rlim); | |
1860 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); | |
1861 else st->print("%uk", rlim.rlim_cur >> 10); | |
1862 | |
1863 st->print(", CORE "); | |
1864 getrlimit(RLIMIT_CORE, &rlim); | |
1865 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); | |
1866 else st->print("%uk", rlim.rlim_cur >> 10); | |
1867 | |
1868 st->print(", NPROC "); | |
1869 getrlimit(RLIMIT_NPROC, &rlim); | |
1870 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); | |
1871 else st->print("%d", rlim.rlim_cur); | |
1872 | |
1873 st->print(", NOFILE "); | |
1874 getrlimit(RLIMIT_NOFILE, &rlim); | |
1875 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); | |
1876 else st->print("%d", rlim.rlim_cur); | |
1877 | |
1878 st->print(", AS "); | |
1879 getrlimit(RLIMIT_AS, &rlim); | |
1880 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity"); | |
1881 else st->print("%uk", rlim.rlim_cur >> 10); | |
1882 st->cr(); | |
1883 | |
1884 // load average | |
1885 st->print("load average:"); | |
1886 double loadavg[3]; | |
1887 os::loadavg(loadavg, 3); | |
1888 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]); | |
1889 st->cr(); | |
1890 } | |
1891 | |
1892 void os::print_memory_info(outputStream* st) { | |
1893 | |
1894 st->print("Memory:"); | |
1895 st->print(" %dk page", os::vm_page_size()>>10); | |
1896 | |
1897 // values in struct sysinfo are "unsigned long" | |
1898 struct sysinfo si; | |
1899 sysinfo(&si); | |
1900 | |
1901 st->print(", physical " UINT64_FORMAT "k", | |
1902 os::physical_memory() >> 10); | |
1903 st->print("(" UINT64_FORMAT "k free)", | |
1904 os::available_memory() >> 10); | |
1905 st->print(", swap " UINT64_FORMAT "k", | |
1906 ((jlong)si.totalswap * si.mem_unit) >> 10); | |
1907 st->print("(" UINT64_FORMAT "k free)", | |
1908 ((jlong)si.freeswap * si.mem_unit) >> 10); | |
1909 st->cr(); | |
1910 } | |
1911 | |
1912 // Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific | |
1913 // but they're the same for all the linux arch that we support | |
1914 // and they're the same for solaris but there's no common place to put this. | |
1915 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR", | |
1916 "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG", | |
1917 "ILL_COPROC", "ILL_BADSTK" }; | |
1918 | |
1919 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV", | |
1920 "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES", | |
1921 "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" }; | |
1922 | |
1923 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" }; | |
1924 | |
1925 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" }; | |
1926 | |
1927 void os::print_siginfo(outputStream* st, void* siginfo) { | |
1928 st->print("siginfo:"); | |
1929 | |
1930 const int buflen = 100; | |
1931 char buf[buflen]; | |
1932 siginfo_t *si = (siginfo_t*)siginfo; | |
1933 st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen)); | |
1934 if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) { | |
1935 st->print("si_errno=%s", buf); | |
1936 } else { | |
1937 st->print("si_errno=%d", si->si_errno); | |
1938 } | |
1939 const int c = si->si_code; | |
1940 assert(c > 0, "unexpected si_code"); | |
1941 switch (si->si_signo) { | |
1942 case SIGILL: | |
1943 st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]); | |
1944 st->print(", si_addr=" PTR_FORMAT, si->si_addr); | |
1945 break; | |
1946 case SIGFPE: | |
1947 st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]); | |
1948 st->print(", si_addr=" PTR_FORMAT, si->si_addr); | |
1949 break; | |
1950 case SIGSEGV: | |
1951 st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]); | |
1952 st->print(", si_addr=" PTR_FORMAT, si->si_addr); | |
1953 break; | |
1954 case SIGBUS: | |
1955 st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]); | |
1956 st->print(", si_addr=" PTR_FORMAT, si->si_addr); | |
1957 break; | |
1958 default: | |
1959 st->print(", si_code=%d", si->si_code); | |
1960 // no si_addr | |
1961 } | |
1962 | |
1963 if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) && | |
1964 UseSharedSpaces) { | |
1965 FileMapInfo* mapinfo = FileMapInfo::current_info(); | |
1966 if (mapinfo->is_in_shared_space(si->si_addr)) { | |
1967 st->print("\n\nError accessing class data sharing archive." \ | |
1968 " Mapped file inaccessible during execution, " \ | |
1969 " possible disk/network problem."); | |
1970 } | |
1971 } | |
1972 st->cr(); | |
1973 } | |
1974 | |
1975 | |
1976 static void print_signal_handler(outputStream* st, int sig, | |
1977 char* buf, size_t buflen); | |
1978 | |
1979 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { | |
1980 st->print_cr("Signal Handlers:"); | |
1981 print_signal_handler(st, SIGSEGV, buf, buflen); | |
1982 print_signal_handler(st, SIGBUS , buf, buflen); | |
1983 print_signal_handler(st, SIGFPE , buf, buflen); | |
1984 print_signal_handler(st, SIGPIPE, buf, buflen); | |
1985 print_signal_handler(st, SIGXFSZ, buf, buflen); | |
1986 print_signal_handler(st, SIGILL , buf, buflen); | |
1987 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen); | |
1988 print_signal_handler(st, SR_signum, buf, buflen); | |
1989 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); | |
1990 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); | |
1991 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); | |
1992 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); | |
1993 } | |
1994 | |
1995 static char saved_jvm_path[MAXPATHLEN] = {0}; | |
1996 | |
1997 // Find the full path to the current module, libjvm.so or libjvm_g.so | |
1998 void os::jvm_path(char *buf, jint len) { | |
1999 // Error checking. | |
2000 if (len < MAXPATHLEN) { | |
2001 assert(false, "must use a large-enough buffer"); | |
2002 buf[0] = '\0'; | |
2003 return; | |
2004 } | |
2005 // Lazy resolve the path to current module. | |
2006 if (saved_jvm_path[0] != 0) { | |
2007 strcpy(buf, saved_jvm_path); | |
2008 return; | |
2009 } | |
2010 | |
2011 char dli_fname[MAXPATHLEN]; | |
2012 bool ret = dll_address_to_library_name( | |
2013 CAST_FROM_FN_PTR(address, os::jvm_path), | |
2014 dli_fname, sizeof(dli_fname), NULL); | |
2015 assert(ret != 0, "cannot locate libjvm"); | |
2016 realpath(dli_fname, buf); | |
2017 | |
2018 if (strcmp(Arguments::sun_java_launcher(), "gamma") == 0) { | |
2019 // Support for the gamma launcher. Typical value for buf is | |
2020 // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so". If "/jre/lib/" appears at | |
2021 // the right place in the string, then assume we are installed in a JDK and | |
2022 // we're done. Otherwise, check for a JAVA_HOME environment variable and fix | |
2023 // up the path so it looks like libjvm.so is installed there (append a | |
2024 // fake suffix hotspot/libjvm.so). | |
2025 const char *p = buf + strlen(buf) - 1; | |
2026 for (int count = 0; p > buf && count < 5; ++count) { | |
2027 for (--p; p > buf && *p != '/'; --p) | |
2028 /* empty */ ; | |
2029 } | |
2030 | |
2031 if (strncmp(p, "/jre/lib/", 9) != 0) { | |
2032 // Look for JAVA_HOME in the environment. | |
2033 char* java_home_var = ::getenv("JAVA_HOME"); | |
2034 if (java_home_var != NULL && java_home_var[0] != 0) { | |
2035 // Check the current module name "libjvm.so" or "libjvm_g.so". | |
2036 p = strrchr(buf, '/'); | |
2037 assert(strstr(p, "/libjvm") == p, "invalid library name"); | |
2038 p = strstr(p, "_g") ? "_g" : ""; | |
2039 | |
2040 realpath(java_home_var, buf); | |
2041 sprintf(buf + strlen(buf), "/jre/lib/%s", cpu_arch); | |
2042 if (0 == access(buf, F_OK)) { | |
2043 // Use current module name "libjvm[_g].so" instead of | |
2044 // "libjvm"debug_only("_g")".so" since for fastdebug version | |
2045 // we should have "libjvm.so" but debug_only("_g") adds "_g"! | |
2046 // It is used when we are choosing the HPI library's name | |
2047 // "libhpi[_g].so" in hpi::initialize_get_interface(). | |
2048 sprintf(buf + strlen(buf), "/hotspot/libjvm%s.so", p); | |
2049 } else { | |
2050 // Go back to path of .so | |
2051 realpath(dli_fname, buf); | |
2052 } | |
2053 } | |
2054 } | |
2055 } | |
2056 | |
2057 strcpy(saved_jvm_path, buf); | |
2058 } | |
2059 | |
2060 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { | |
2061 // no prefix required, not even "_" | |
2062 } | |
2063 | |
2064 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { | |
2065 // no suffix required | |
2066 } | |
2067 | |
2068 //////////////////////////////////////////////////////////////////////////////// | |
2069 // sun.misc.Signal support | |
2070 | |
2071 static volatile jint sigint_count = 0; | |
2072 | |
2073 static void | |
2074 UserHandler(int sig, void *siginfo, void *context) { | |
2075 // 4511530 - sem_post is serialized and handled by the manager thread. When | |
2076 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We | |
2077 // don't want to flood the manager thread with sem_post requests. | |
2078 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) | |
2079 return; | |
2080 | |
2081 // Ctrl-C is pressed during error reporting, likely because the error | |
2082 // handler fails to abort. Let VM die immediately. | |
2083 if (sig == SIGINT && is_error_reported()) { | |
2084 os::die(); | |
2085 } | |
2086 | |
2087 os::signal_notify(sig); | |
2088 } | |
2089 | |
2090 void* os::user_handler() { | |
2091 return CAST_FROM_FN_PTR(void*, UserHandler); | |
2092 } | |
2093 | |
2094 extern "C" { | |
2095 typedef void (*sa_handler_t)(int); | |
2096 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); | |
2097 } | |
2098 | |
2099 void* os::signal(int signal_number, void* handler) { | |
2100 struct sigaction sigAct, oldSigAct; | |
2101 | |
2102 sigfillset(&(sigAct.sa_mask)); | |
2103 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; | |
2104 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); | |
2105 | |
2106 if (sigaction(signal_number, &sigAct, &oldSigAct)) { | |
2107 // -1 means registration failed | |
2108 return (void *)-1; | |
2109 } | |
2110 | |
2111 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); | |
2112 } | |
2113 | |
2114 void os::signal_raise(int signal_number) { | |
2115 ::raise(signal_number); | |
2116 } | |
2117 | |
2118 /* | |
2119 * The following code is moved from os.cpp for making this | |
2120 * code platform specific, which it is by its very nature. | |
2121 */ | |
2122 | |
2123 // Will be modified when max signal is changed to be dynamic | |
2124 int os::sigexitnum_pd() { | |
2125 return NSIG; | |
2126 } | |
2127 | |
2128 // a counter for each possible signal value | |
2129 static volatile jint pending_signals[NSIG+1] = { 0 }; | |
2130 | |
2131 // Linux(POSIX) specific hand shaking semaphore. | |
2132 static sem_t sig_sem; | |
2133 | |
2134 void os::signal_init_pd() { | |
2135 // Initialize signal structures | |
2136 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); | |
2137 | |
2138 // Initialize signal semaphore | |
2139 ::sem_init(&sig_sem, 0, 0); | |
2140 } | |
2141 | |
2142 void os::signal_notify(int sig) { | |
2143 Atomic::inc(&pending_signals[sig]); | |
2144 ::sem_post(&sig_sem); | |
2145 } | |
2146 | |
2147 static int check_pending_signals(bool wait) { | |
2148 Atomic::store(0, &sigint_count); | |
2149 for (;;) { | |
2150 for (int i = 0; i < NSIG + 1; i++) { | |
2151 jint n = pending_signals[i]; | |
2152 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { | |
2153 return i; | |
2154 } | |
2155 } | |
2156 if (!wait) { | |
2157 return -1; | |
2158 } | |
2159 JavaThread *thread = JavaThread::current(); | |
2160 ThreadBlockInVM tbivm(thread); | |
2161 | |
2162 bool threadIsSuspended; | |
2163 do { | |
2164 thread->set_suspend_equivalent(); | |
2165 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() | |
2166 ::sem_wait(&sig_sem); | |
2167 | |
2168 // were we externally suspended while we were waiting? | |
2169 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); | |
2170 if (threadIsSuspended) { | |
2171 // | |
2172 // The semaphore has been incremented, but while we were waiting | |
2173 // another thread suspended us. We don't want to continue running | |
2174 // while suspended because that would surprise the thread that | |
2175 // suspended us. | |
2176 // | |
2177 ::sem_post(&sig_sem); | |
2178 | |
2179 thread->java_suspend_self(); | |
2180 } | |
2181 } while (threadIsSuspended); | |
2182 } | |
2183 } | |
2184 | |
2185 int os::signal_lookup() { | |
2186 return check_pending_signals(false); | |
2187 } | |
2188 | |
2189 int os::signal_wait() { | |
2190 return check_pending_signals(true); | |
2191 } | |
2192 | |
2193 //////////////////////////////////////////////////////////////////////////////// | |
2194 // Virtual Memory | |
2195 | |
2196 int os::vm_page_size() { | |
2197 // Seems redundant as all get out | |
2198 assert(os::Linux::page_size() != -1, "must call os::init"); | |
2199 return os::Linux::page_size(); | |
2200 } | |
2201 | |
2202 // Solaris allocates memory by pages. | |
2203 int os::vm_allocation_granularity() { | |
2204 assert(os::Linux::page_size() != -1, "must call os::init"); | |
2205 return os::Linux::page_size(); | |
2206 } | |
2207 | |
2208 // Rationale behind this function: | |
2209 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable | |
2210 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get | |
2211 // samples for JITted code. Here we create private executable mapping over the code cache | |
2212 // and then we can use standard (well, almost, as mapping can change) way to provide | |
2213 // info for the reporting script by storing timestamp and location of symbol | |
2214 void linux_wrap_code(char* base, size_t size) { | |
2215 static volatile jint cnt = 0; | |
2216 | |
2217 if (!UseOprofile) { | |
2218 return; | |
2219 } | |
2220 | |
2221 char buf[40]; | |
2222 int num = Atomic::add(1, &cnt); | |
2223 | |
2224 sprintf(buf, "/tmp/hs-vm-%d-%d", os::current_process_id(), num); | |
2225 unlink(buf); | |
2226 | |
2227 int fd = open(buf, O_CREAT | O_RDWR, S_IRWXU); | |
2228 | |
2229 if (fd != -1) { | |
2230 off_t rv = lseek(fd, size-2, SEEK_SET); | |
2231 if (rv != (off_t)-1) { | |
2232 if (write(fd, "", 1) == 1) { | |
2233 mmap(base, size, | |
2234 PROT_READ|PROT_WRITE|PROT_EXEC, | |
2235 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); | |
2236 } | |
2237 } | |
2238 close(fd); | |
2239 unlink(buf); | |
2240 } | |
2241 } | |
2242 | |
2243 // NOTE: Linux kernel does not really reserve the pages for us. | |
2244 // All it does is to check if there are enough free pages | |
2245 // left at the time of mmap(). This could be a potential | |
2246 // problem. | |
2247 bool os::commit_memory(char* addr, size_t size) { | |
2248 uintptr_t res = (uintptr_t) ::mmap(addr, size, | |
2249 PROT_READ|PROT_WRITE|PROT_EXEC, | |
2250 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); | |
2251 return res != (uintptr_t) MAP_FAILED; | |
2252 } | |
2253 | |
2254 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint) { | |
2255 return commit_memory(addr, size); | |
2256 } | |
2257 | |
2258 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) { } | |
141 | 2259 |
2260 void os::free_memory(char *addr, size_t bytes) { | |
2261 uncommit_memory(addr, bytes); | |
2262 } | |
2263 | |
0 | 2264 void os::numa_make_global(char *addr, size_t bytes) { } |
141 | 2265 |
2266 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { | |
2267 Linux::numa_tonode_memory(addr, bytes, lgrp_hint); | |
2268 } | |
2269 | |
2270 bool os::numa_topology_changed() { return false; } | |
2271 | |
2272 size_t os::numa_get_groups_num() { | |
2273 int max_node = Linux::numa_max_node(); | |
2274 return max_node > 0 ? max_node + 1 : 1; | |
2275 } | |
2276 | |
2277 int os::numa_get_group_id() { | |
2278 int cpu_id = Linux::sched_getcpu(); | |
2279 if (cpu_id != -1) { | |
2280 int lgrp_id = Linux::get_node_by_cpu(cpu_id); | |
2281 if (lgrp_id != -1) { | |
2282 return lgrp_id; | |
2283 } | |
0 | 2284 } |
2285 return 0; | |
2286 } | |
2287 | |
141 | 2288 size_t os::numa_get_leaf_groups(int *ids, size_t size) { |
2289 for (size_t i = 0; i < size; i++) { | |
2290 ids[i] = i; | |
2291 } | |
2292 return size; | |
2293 } | |
2294 | |
0 | 2295 bool os::get_page_info(char *start, page_info* info) { |
2296 return false; | |
2297 } | |
2298 | |
2299 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) { | |
2300 return end; | |
2301 } | |
2302 | |
141 | 2303 extern "C" void numa_warn(int number, char *where, ...) { } |
2304 extern "C" void numa_error(char *where) { } | |
2305 | |
2306 void os::Linux::libnuma_init() { | |
2307 // sched_getcpu() should be in libc. | |
2308 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, | |
2309 dlsym(RTLD_DEFAULT, "sched_getcpu"))); | |
2310 | |
2311 if (sched_getcpu() != -1) { // Does it work? | |
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2312 void *handle = dlopen("libnuma.so.1", RTLD_LAZY); |
141 | 2313 if (handle != NULL) { |
2314 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, | |
2315 dlsym(handle, "numa_node_to_cpus"))); | |
2316 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, | |
2317 dlsym(handle, "numa_max_node"))); | |
2318 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, | |
2319 dlsym(handle, "numa_available"))); | |
2320 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, | |
2321 dlsym(handle, "numa_tonode_memory"))); | |
2322 if (numa_available() != -1) { | |
2323 // Create a cpu -> node mapping | |
2324 _cpu_to_node = new (ResourceObj::C_HEAP) GrowableArray<int>(0, true); | |
2325 rebuild_cpu_to_node_map(); | |
2326 } | |
2327 } | |
2328 } | |
2329 } | |
2330 | |
2331 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. | |
2332 // The table is later used in get_node_by_cpu(). | |
2333 void os::Linux::rebuild_cpu_to_node_map() { | |
2334 int cpu_num = os::active_processor_count(); | |
2335 cpu_to_node()->clear(); | |
2336 cpu_to_node()->at_grow(cpu_num - 1); | |
2337 int node_num = numa_get_groups_num(); | |
2338 int cpu_map_size = (cpu_num + BitsPerLong - 1) / BitsPerLong; | |
2339 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size); | |
2340 for (int i = 0; i < node_num; i++) { | |
2341 if (numa_node_to_cpus(i, cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { | |
2342 for (int j = 0; j < cpu_map_size; j++) { | |
2343 if (cpu_map[j] != 0) { | |
2344 for (int k = 0; k < BitsPerLong; k++) { | |
2345 if (cpu_map[j] & (1UL << k)) { | |
2346 cpu_to_node()->at_put(j * BitsPerLong + k, i); | |
2347 } | |
2348 } | |
2349 } | |
2350 } | |
2351 } | |
2352 } | |
2353 FREE_C_HEAP_ARRAY(unsigned long, cpu_map); | |
2354 } | |
2355 | |
2356 int os::Linux::get_node_by_cpu(int cpu_id) { | |
2357 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { | |
2358 return cpu_to_node()->at(cpu_id); | |
2359 } | |
2360 return -1; | |
2361 } | |
2362 | |
2363 GrowableArray<int>* os::Linux::_cpu_to_node; | |
2364 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu; | |
2365 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus; | |
2366 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node; | |
2367 os::Linux::numa_available_func_t os::Linux::_numa_available; | |
2368 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory; | |
2369 | |
2370 | |
0 | 2371 bool os::uncommit_memory(char* addr, size_t size) { |
2372 return ::mmap(addr, size, | |
2373 PROT_READ|PROT_WRITE|PROT_EXEC, | |
2374 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0) | |
2375 != MAP_FAILED; | |
2376 } | |
2377 | |
2378 static address _highest_vm_reserved_address = NULL; | |
2379 | |
2380 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory | |
2381 // at 'requested_addr'. If there are existing memory mappings at the same | |
2382 // location, however, they will be overwritten. If 'fixed' is false, | |
2383 // 'requested_addr' is only treated as a hint, the return value may or | |
2384 // may not start from the requested address. Unlike Linux mmap(), this | |
2385 // function returns NULL to indicate failure. | |
2386 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { | |
2387 char * addr; | |
2388 int flags; | |
2389 | |
2390 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; | |
2391 if (fixed) { | |
2392 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address"); | |
2393 flags |= MAP_FIXED; | |
2394 } | |
2395 | |
2396 addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE|PROT_EXEC, | |
2397 flags, -1, 0); | |
2398 | |
2399 if (addr != MAP_FAILED) { | |
2400 // anon_mmap() should only get called during VM initialization, | |
2401 // don't need lock (actually we can skip locking even it can be called | |
2402 // from multiple threads, because _highest_vm_reserved_address is just a | |
2403 // hint about the upper limit of non-stack memory regions.) | |
2404 if ((address)addr + bytes > _highest_vm_reserved_address) { | |
2405 _highest_vm_reserved_address = (address)addr + bytes; | |
2406 } | |
2407 } | |
2408 | |
2409 return addr == MAP_FAILED ? NULL : addr; | |
2410 } | |
2411 | |
2412 // Don't update _highest_vm_reserved_address, because there might be memory | |
2413 // regions above addr + size. If so, releasing a memory region only creates | |
2414 // a hole in the address space, it doesn't help prevent heap-stack collision. | |
2415 // | |
2416 static int anon_munmap(char * addr, size_t size) { | |
2417 return ::munmap(addr, size) == 0; | |
2418 } | |
2419 | |
2420 char* os::reserve_memory(size_t bytes, char* requested_addr, | |
2421 size_t alignment_hint) { | |
2422 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); | |
2423 } | |
2424 | |
2425 bool os::release_memory(char* addr, size_t size) { | |
2426 return anon_munmap(addr, size); | |
2427 } | |
2428 | |
2429 static address highest_vm_reserved_address() { | |
2430 return _highest_vm_reserved_address; | |
2431 } | |
2432 | |
2433 static bool linux_mprotect(char* addr, size_t size, int prot) { | |
2434 // Linux wants the mprotect address argument to be page aligned. | |
2435 char* bottom = (char*)align_size_down((intptr_t)addr, os::Linux::page_size()); | |
2436 | |
2437 // According to SUSv3, mprotect() should only be used with mappings | |
2438 // established by mmap(), and mmap() always maps whole pages. Unaligned | |
2439 // 'addr' likely indicates problem in the VM (e.g. trying to change | |
2440 // protection of malloc'ed or statically allocated memory). Check the | |
2441 // caller if you hit this assert. | |
2442 assert(addr == bottom, "sanity check"); | |
2443 | |
2444 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size()); | |
2445 return ::mprotect(bottom, size, prot) == 0; | |
2446 } | |
2447 | |
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2448 // Set protections specified |
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2449 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, |
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2450 bool is_committed) { |
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2451 unsigned int p = 0; |
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2452 switch (prot) { |
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2453 case MEM_PROT_NONE: p = PROT_NONE; break; |
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2454 case MEM_PROT_READ: p = PROT_READ; break; |
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2455 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; |
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2456 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; |
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2457 default: |
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2458 ShouldNotReachHere(); |
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2459 } |
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2460 // is_committed is unused. |
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2461 return linux_mprotect(addr, bytes, p); |
0 | 2462 } |
2463 | |
2464 bool os::guard_memory(char* addr, size_t size) { | |
2465 return linux_mprotect(addr, size, PROT_NONE); | |
2466 } | |
2467 | |
2468 bool os::unguard_memory(char* addr, size_t size) { | |
2469 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE|PROT_EXEC); | |
2470 } | |
2471 | |
2472 // Large page support | |
2473 | |
2474 static size_t _large_page_size = 0; | |
2475 | |
2476 bool os::large_page_init() { | |
2477 if (!UseLargePages) return false; | |
2478 | |
2479 if (LargePageSizeInBytes) { | |
2480 _large_page_size = LargePageSizeInBytes; | |
2481 } else { | |
2482 // large_page_size on Linux is used to round up heap size. x86 uses either | |
2483 // 2M or 4M page, depending on whether PAE (Physical Address Extensions) | |
2484 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use | |
2485 // page as large as 256M. | |
2486 // | |
2487 // Here we try to figure out page size by parsing /proc/meminfo and looking | |
2488 // for a line with the following format: | |
2489 // Hugepagesize: 2048 kB | |
2490 // | |
2491 // If we can't determine the value (e.g. /proc is not mounted, or the text | |
2492 // format has been changed), we'll use the largest page size supported by | |
2493 // the processor. | |
2494 | |
2495 _large_page_size = IA32_ONLY(4 * M) AMD64_ONLY(2 * M) IA64_ONLY(256 * M) SPARC_ONLY(4 * M); | |
2496 | |
2497 FILE *fp = fopen("/proc/meminfo", "r"); | |
2498 if (fp) { | |
2499 while (!feof(fp)) { | |
2500 int x = 0; | |
2501 char buf[16]; | |
2502 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { | |
2503 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { | |
2504 _large_page_size = x * K; | |
2505 break; | |
2506 } | |
2507 } else { | |
2508 // skip to next line | |
2509 for (;;) { | |
2510 int ch = fgetc(fp); | |
2511 if (ch == EOF || ch == (int)'\n') break; | |
2512 } | |
2513 } | |
2514 } | |
2515 fclose(fp); | |
2516 } | |
2517 } | |
2518 | |
2519 const size_t default_page_size = (size_t)Linux::page_size(); | |
2520 if (_large_page_size > default_page_size) { | |
2521 _page_sizes[0] = _large_page_size; | |
2522 _page_sizes[1] = default_page_size; | |
2523 _page_sizes[2] = 0; | |
2524 } | |
2525 | |
2526 // Large page support is available on 2.6 or newer kernel, some vendors | |
2527 // (e.g. Redhat) have backported it to their 2.4 based distributions. | |
2528 // We optimistically assume the support is available. If later it turns out | |
2529 // not true, VM will automatically switch to use regular page size. | |
2530 return true; | |
2531 } | |
2532 | |
2533 #ifndef SHM_HUGETLB | |
2534 #define SHM_HUGETLB 04000 | |
2535 #endif | |
2536 | |
2537 char* os::reserve_memory_special(size_t bytes) { | |
2538 assert(UseLargePages, "only for large pages"); | |
2539 | |
2540 key_t key = IPC_PRIVATE; | |
2541 char *addr; | |
2542 | |
2543 bool warn_on_failure = UseLargePages && | |
2544 (!FLAG_IS_DEFAULT(UseLargePages) || | |
2545 !FLAG_IS_DEFAULT(LargePageSizeInBytes) | |
2546 ); | |
2547 char msg[128]; | |
2548 | |
2549 // Create a large shared memory region to attach to based on size. | |
2550 // Currently, size is the total size of the heap | |
2551 int shmid = shmget(key, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); | |
2552 if (shmid == -1) { | |
2553 // Possible reasons for shmget failure: | |
2554 // 1. shmmax is too small for Java heap. | |
2555 // > check shmmax value: cat /proc/sys/kernel/shmmax | |
2556 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax | |
2557 // 2. not enough large page memory. | |
2558 // > check available large pages: cat /proc/meminfo | |
2559 // > increase amount of large pages: | |
2560 // echo new_value > /proc/sys/vm/nr_hugepages | |
2561 // Note 1: different Linux may use different name for this property, | |
2562 // e.g. on Redhat AS-3 it is "hugetlb_pool". | |
2563 // Note 2: it's possible there's enough physical memory available but | |
2564 // they are so fragmented after a long run that they can't | |
2565 // coalesce into large pages. Try to reserve large pages when | |
2566 // the system is still "fresh". | |
2567 if (warn_on_failure) { | |
2568 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno); | |
2569 warning(msg); | |
2570 } | |
2571 return NULL; | |
2572 } | |
2573 | |
2574 // attach to the region | |
2575 addr = (char*)shmat(shmid, NULL, 0); | |
2576 int err = errno; | |
2577 | |
2578 // Remove shmid. If shmat() is successful, the actual shared memory segment | |
2579 // will be deleted when it's detached by shmdt() or when the process | |
2580 // terminates. If shmat() is not successful this will remove the shared | |
2581 // segment immediately. | |
2582 shmctl(shmid, IPC_RMID, NULL); | |
2583 | |
2584 if ((intptr_t)addr == -1) { | |
2585 if (warn_on_failure) { | |
2586 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err); | |
2587 warning(msg); | |
2588 } | |
2589 return NULL; | |
2590 } | |
2591 | |
2592 return addr; | |
2593 } | |
2594 | |
2595 bool os::release_memory_special(char* base, size_t bytes) { | |
2596 // detaching the SHM segment will also delete it, see reserve_memory_special() | |
2597 int rslt = shmdt(base); | |
2598 return rslt == 0; | |
2599 } | |
2600 | |
2601 size_t os::large_page_size() { | |
2602 return _large_page_size; | |
2603 } | |
2604 | |
2605 // Linux does not support anonymous mmap with large page memory. The only way | |
2606 // to reserve large page memory without file backing is through SysV shared | |
2607 // memory API. The entire memory region is committed and pinned upfront. | |
2608 // Hopefully this will change in the future... | |
2609 bool os::can_commit_large_page_memory() { | |
2610 return false; | |
2611 } | |
2612 | |
79
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2613 bool os::can_execute_large_page_memory() { |
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2614 return false; |
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2615 } |
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2616 |
0 | 2617 // Reserve memory at an arbitrary address, only if that area is |
2618 // available (and not reserved for something else). | |
2619 | |
2620 char* os::attempt_reserve_memory_at(size_t bytes, char* requested_addr) { | |
2621 const int max_tries = 10; | |
2622 char* base[max_tries]; | |
2623 size_t size[max_tries]; | |
2624 const size_t gap = 0x000000; | |
2625 | |
2626 // Assert only that the size is a multiple of the page size, since | |
2627 // that's all that mmap requires, and since that's all we really know | |
2628 // about at this low abstraction level. If we need higher alignment, | |
2629 // we can either pass an alignment to this method or verify alignment | |
2630 // in one of the methods further up the call chain. See bug 5044738. | |
2631 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); | |
2632 | |
2633 // Repeatedly allocate blocks until the block is allocated at the | |
2634 // right spot. Give up after max_tries. Note that reserve_memory() will | |
2635 // automatically update _highest_vm_reserved_address if the call is | |
2636 // successful. The variable tracks the highest memory address every reserved | |
2637 // by JVM. It is used to detect heap-stack collision if running with | |
2638 // fixed-stack LinuxThreads. Because here we may attempt to reserve more | |
2639 // space than needed, it could confuse the collision detecting code. To | |
2640 // solve the problem, save current _highest_vm_reserved_address and | |
2641 // calculate the correct value before return. | |
2642 address old_highest = _highest_vm_reserved_address; | |
2643 | |
2644 // Linux mmap allows caller to pass an address as hint; give it a try first, | |
2645 // if kernel honors the hint then we can return immediately. | |
2646 char * addr = anon_mmap(requested_addr, bytes, false); | |
2647 if (addr == requested_addr) { | |
2648 return requested_addr; | |
2649 } | |
2650 | |
2651 if (addr != NULL) { | |
2652 // mmap() is successful but it fails to reserve at the requested address | |
2653 anon_munmap(addr, bytes); | |
2654 } | |
2655 | |
2656 int i; | |
2657 for (i = 0; i < max_tries; ++i) { | |
2658 base[i] = reserve_memory(bytes); | |
2659 | |
2660 if (base[i] != NULL) { | |
2661 // Is this the block we wanted? | |
2662 if (base[i] == requested_addr) { | |
2663 size[i] = bytes; | |
2664 break; | |
2665 } | |
2666 | |
2667 // Does this overlap the block we wanted? Give back the overlapped | |
2668 // parts and try again. | |
2669 | |
2670 size_t top_overlap = requested_addr + (bytes + gap) - base[i]; | |
2671 if (top_overlap >= 0 && top_overlap < bytes) { | |
2672 unmap_memory(base[i], top_overlap); | |
2673 base[i] += top_overlap; | |
2674 size[i] = bytes - top_overlap; | |
2675 } else { | |
2676 size_t bottom_overlap = base[i] + bytes - requested_addr; | |
2677 if (bottom_overlap >= 0 && bottom_overlap < bytes) { | |
2678 unmap_memory(requested_addr, bottom_overlap); | |
2679 size[i] = bytes - bottom_overlap; | |
2680 } else { | |
2681 size[i] = bytes; | |
2682 } | |
2683 } | |
2684 } | |
2685 } | |
2686 | |
2687 // Give back the unused reserved pieces. | |
2688 | |
2689 for (int j = 0; j < i; ++j) { | |
2690 if (base[j] != NULL) { | |
2691 unmap_memory(base[j], size[j]); | |
2692 } | |
2693 } | |
2694 | |
2695 if (i < max_tries) { | |
2696 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes); | |
2697 return requested_addr; | |
2698 } else { | |
2699 _highest_vm_reserved_address = old_highest; | |
2700 return NULL; | |
2701 } | |
2702 } | |
2703 | |
2704 size_t os::read(int fd, void *buf, unsigned int nBytes) { | |
2705 return ::read(fd, buf, nBytes); | |
2706 } | |
2707 | |
2708 // TODO-FIXME: reconcile Solaris' os::sleep with the linux variation. | |
2709 // Solaris uses poll(), linux uses park(). | |
2710 // Poll() is likely a better choice, assuming that Thread.interrupt() | |
2711 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with | |
2712 // SIGSEGV, see 4355769. | |
2713 | |
2714 const int NANOSECS_PER_MILLISECS = 1000000; | |
2715 | |
2716 int os::sleep(Thread* thread, jlong millis, bool interruptible) { | |
2717 assert(thread == Thread::current(), "thread consistency check"); | |
2718 | |
2719 ParkEvent * const slp = thread->_SleepEvent ; | |
2720 slp->reset() ; | |
2721 OrderAccess::fence() ; | |
2722 | |
2723 if (interruptible) { | |
2724 jlong prevtime = javaTimeNanos(); | |
2725 | |
2726 for (;;) { | |
2727 if (os::is_interrupted(thread, true)) { | |
2728 return OS_INTRPT; | |
2729 } | |
2730 | |
2731 jlong newtime = javaTimeNanos(); | |
2732 | |
2733 if (newtime - prevtime < 0) { | |
2734 // time moving backwards, should only happen if no monotonic clock | |
2735 // not a guarantee() because JVM should not abort on kernel/glibc bugs | |
2736 assert(!Linux::supports_monotonic_clock(), "time moving backwards"); | |
2737 } else { | |
2738 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISECS; | |
2739 } | |
2740 | |
2741 if(millis <= 0) { | |
2742 return OS_OK; | |
2743 } | |
2744 | |
2745 prevtime = newtime; | |
2746 | |
2747 { | |
2748 assert(thread->is_Java_thread(), "sanity check"); | |
2749 JavaThread *jt = (JavaThread *) thread; | |
2750 ThreadBlockInVM tbivm(jt); | |
2751 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */); | |
2752 | |
2753 jt->set_suspend_equivalent(); | |
2754 // cleared by handle_special_suspend_equivalent_condition() or | |
2755 // java_suspend_self() via check_and_wait_while_suspended() | |
2756 | |
2757 slp->park(millis); | |
2758 | |
2759 // were we externally suspended while we were waiting? | |
2760 jt->check_and_wait_while_suspended(); | |
2761 } | |
2762 } | |
2763 } else { | |
2764 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); | |
2765 jlong prevtime = javaTimeNanos(); | |
2766 | |
2767 for (;;) { | |
2768 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on | |
2769 // the 1st iteration ... | |
2770 jlong newtime = javaTimeNanos(); | |
2771 | |
2772 if (newtime - prevtime < 0) { | |
2773 // time moving backwards, should only happen if no monotonic clock | |
2774 // not a guarantee() because JVM should not abort on kernel/glibc bugs | |
2775 assert(!Linux::supports_monotonic_clock(), "time moving backwards"); | |
2776 } else { | |
2777 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISECS; | |
2778 } | |
2779 | |
2780 if(millis <= 0) break ; | |
2781 | |
2782 prevtime = newtime; | |
2783 slp->park(millis); | |
2784 } | |
2785 return OS_OK ; | |
2786 } | |
2787 } | |
2788 | |
2789 int os::naked_sleep() { | |
2790 // %% make the sleep time an integer flag. for now use 1 millisec. | |
2791 return os::sleep(Thread::current(), 1, false); | |
2792 } | |
2793 | |
2794 // Sleep forever; naked call to OS-specific sleep; use with CAUTION | |
2795 void os::infinite_sleep() { | |
2796 while (true) { // sleep forever ... | |
2797 ::sleep(100); // ... 100 seconds at a time | |
2798 } | |
2799 } | |
2800 | |
2801 // Used to convert frequent JVM_Yield() to nops | |
2802 bool os::dont_yield() { | |
2803 return DontYieldALot; | |
2804 } | |
2805 | |
2806 void os::yield() { | |
2807 sched_yield(); | |
2808 } | |
2809 | |
2810 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;} | |
2811 | |
2812 void os::yield_all(int attempts) { | |
2813 // Yields to all threads, including threads with lower priorities | |
2814 // Threads on Linux are all with same priority. The Solaris style | |
2815 // os::yield_all() with nanosleep(1ms) is not necessary. | |
2816 sched_yield(); | |
2817 } | |
2818 | |
2819 // Called from the tight loops to possibly influence time-sharing heuristics | |
2820 void os::loop_breaker(int attempts) { | |
2821 os::yield_all(attempts); | |
2822 } | |
2823 | |
2824 //////////////////////////////////////////////////////////////////////////////// | |
2825 // thread priority support | |
2826 | |
2827 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER | |
2828 // only supports dynamic priority, static priority must be zero. For real-time | |
2829 // applications, Linux supports SCHED_RR which allows static priority (1-99). | |
2830 // However, for large multi-threaded applications, SCHED_RR is not only slower | |
2831 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out | |
2832 // of 5 runs - Sep 2005). | |
2833 // | |
2834 // The following code actually changes the niceness of kernel-thread/LWP. It | |
2835 // has an assumption that setpriority() only modifies one kernel-thread/LWP, | |
2836 // not the entire user process, and user level threads are 1:1 mapped to kernel | |
2837 // threads. It has always been the case, but could change in the future. For | |
2838 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). | |
2839 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. | |
2840 | |
2841 int os::java_to_os_priority[MaxPriority + 1] = { | |
2842 19, // 0 Entry should never be used | |
2843 | |
2844 4, // 1 MinPriority | |
2845 3, // 2 | |
2846 2, // 3 | |
2847 | |
2848 1, // 4 | |
2849 0, // 5 NormPriority | |
2850 -1, // 6 | |
2851 | |
2852 -2, // 7 | |
2853 -3, // 8 | |
2854 -4, // 9 NearMaxPriority | |
2855 | |
2856 -5 // 10 MaxPriority | |
2857 }; | |
2858 | |
2859 static int prio_init() { | |
2860 if (ThreadPriorityPolicy == 1) { | |
2861 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 | |
2862 // if effective uid is not root. Perhaps, a more elegant way of doing | |
2863 // this is to test CAP_SYS_NICE capability, but that will require libcap.so | |
2864 if (geteuid() != 0) { | |
2865 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { | |
2866 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux"); | |
2867 } | |
2868 ThreadPriorityPolicy = 0; | |
2869 } | |
2870 } | |
2871 return 0; | |
2872 } | |
2873 | |
2874 OSReturn os::set_native_priority(Thread* thread, int newpri) { | |
2875 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK; | |
2876 | |
2877 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); | |
2878 return (ret == 0) ? OS_OK : OS_ERR; | |
2879 } | |
2880 | |
2881 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) { | |
2882 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) { | |
2883 *priority_ptr = java_to_os_priority[NormPriority]; | |
2884 return OS_OK; | |
2885 } | |
2886 | |
2887 errno = 0; | |
2888 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); | |
2889 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); | |
2890 } | |
2891 | |
2892 // Hint to the underlying OS that a task switch would not be good. | |
2893 // Void return because it's a hint and can fail. | |
2894 void os::hint_no_preempt() {} | |
2895 | |
2896 //////////////////////////////////////////////////////////////////////////////// | |
2897 // suspend/resume support | |
2898 | |
2899 // the low-level signal-based suspend/resume support is a remnant from the | |
2900 // old VM-suspension that used to be for java-suspension, safepoints etc, | |
2901 // within hotspot. Now there is a single use-case for this: | |
2902 // - calling get_thread_pc() on the VMThread by the flat-profiler task | |
2903 // that runs in the watcher thread. | |
2904 // The remaining code is greatly simplified from the more general suspension | |
2905 // code that used to be used. | |
2906 // | |
2907 // The protocol is quite simple: | |
2908 // - suspend: | |
2909 // - sends a signal to the target thread | |
2910 // - polls the suspend state of the osthread using a yield loop | |
2911 // - target thread signal handler (SR_handler) sets suspend state | |
2912 // and blocks in sigsuspend until continued | |
2913 // - resume: | |
2914 // - sets target osthread state to continue | |
2915 // - sends signal to end the sigsuspend loop in the SR_handler | |
2916 // | |
2917 // Note that the SR_lock plays no role in this suspend/resume protocol. | |
2918 // | |
2919 | |
2920 static void resume_clear_context(OSThread *osthread) { | |
2921 osthread->set_ucontext(NULL); | |
2922 osthread->set_siginfo(NULL); | |
2923 | |
2924 // notify the suspend action is completed, we have now resumed | |
2925 osthread->sr.clear_suspended(); | |
2926 } | |
2927 | |
2928 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) { | |
2929 osthread->set_ucontext(context); | |
2930 osthread->set_siginfo(siginfo); | |
2931 } | |
2932 | |
2933 // | |
2934 // Handler function invoked when a thread's execution is suspended or | |
2935 // resumed. We have to be careful that only async-safe functions are | |
2936 // called here (Note: most pthread functions are not async safe and | |
2937 // should be avoided.) | |
2938 // | |
2939 // Note: sigwait() is a more natural fit than sigsuspend() from an | |
2940 // interface point of view, but sigwait() prevents the signal hander | |
2941 // from being run. libpthread would get very confused by not having | |
2942 // its signal handlers run and prevents sigwait()'s use with the | |
2943 // mutex granting granting signal. | |
2944 // | |
2945 // Currently only ever called on the VMThread | |
2946 // | |
2947 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { | |
2948 // Save and restore errno to avoid confusing native code with EINTR | |
2949 // after sigsuspend. | |
2950 int old_errno = errno; | |
2951 | |
2952 Thread* thread = Thread::current(); | |
2953 OSThread* osthread = thread->osthread(); | |
2954 assert(thread->is_VM_thread(), "Must be VMThread"); | |
2955 // read current suspend action | |
2956 int action = osthread->sr.suspend_action(); | |
2957 if (action == SR_SUSPEND) { | |
2958 suspend_save_context(osthread, siginfo, context); | |
2959 | |
2960 // Notify the suspend action is about to be completed. do_suspend() | |
2961 // waits until SR_SUSPENDED is set and then returns. We will wait | |
2962 // here for a resume signal and that completes the suspend-other | |
2963 // action. do_suspend/do_resume is always called as a pair from | |
2964 // the same thread - so there are no races | |
2965 | |
2966 // notify the caller | |
2967 osthread->sr.set_suspended(); | |
2968 | |
2969 sigset_t suspend_set; // signals for sigsuspend() | |
2970 | |
2971 // get current set of blocked signals and unblock resume signal | |
2972 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); | |
2973 sigdelset(&suspend_set, SR_signum); | |
2974 | |
2975 // wait here until we are resumed | |
2976 do { | |
2977 sigsuspend(&suspend_set); | |
2978 // ignore all returns until we get a resume signal | |
2979 } while (osthread->sr.suspend_action() != SR_CONTINUE); | |
2980 | |
2981 resume_clear_context(osthread); | |
2982 | |
2983 } else { | |
2984 assert(action == SR_CONTINUE, "unexpected sr action"); | |
2985 // nothing special to do - just leave the handler | |
2986 } | |
2987 | |
2988 errno = old_errno; | |
2989 } | |
2990 | |
2991 | |
2992 static int SR_initialize() { | |
2993 struct sigaction act; | |
2994 char *s; | |
2995 /* Get signal number to use for suspend/resume */ | |
2996 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { | |
2997 int sig = ::strtol(s, 0, 10); | |
2998 if (sig > 0 || sig < _NSIG) { | |
2999 SR_signum = sig; | |
3000 } | |
3001 } | |
3002 | |
3003 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, | |
3004 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); | |
3005 | |
3006 sigemptyset(&SR_sigset); | |
3007 sigaddset(&SR_sigset, SR_signum); | |
3008 | |
3009 /* Set up signal handler for suspend/resume */ | |
3010 act.sa_flags = SA_RESTART|SA_SIGINFO; | |
3011 act.sa_handler = (void (*)(int)) SR_handler; | |
3012 | |
3013 // SR_signum is blocked by default. | |
3014 // 4528190 - We also need to block pthread restart signal (32 on all | |
3015 // supported Linux platforms). Note that LinuxThreads need to block | |
3016 // this signal for all threads to work properly. So we don't have | |
3017 // to use hard-coded signal number when setting up the mask. | |
3018 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); | |
3019 | |
3020 if (sigaction(SR_signum, &act, 0) == -1) { | |
3021 return -1; | |
3022 } | |
3023 | |
3024 // Save signal flag | |
3025 os::Linux::set_our_sigflags(SR_signum, act.sa_flags); | |
3026 return 0; | |
3027 } | |
3028 | |
3029 static int SR_finalize() { | |
3030 return 0; | |
3031 } | |
3032 | |
3033 | |
3034 // returns true on success and false on error - really an error is fatal | |
3035 // but this seems the normal response to library errors | |
3036 static bool do_suspend(OSThread* osthread) { | |
3037 // mark as suspended and send signal | |
3038 osthread->sr.set_suspend_action(SR_SUSPEND); | |
3039 int status = pthread_kill(osthread->pthread_id(), SR_signum); | |
3040 assert_status(status == 0, status, "pthread_kill"); | |
3041 | |
3042 // check status and wait until notified of suspension | |
3043 if (status == 0) { | |
3044 for (int i = 0; !osthread->sr.is_suspended(); i++) { | |
3045 os::yield_all(i); | |
3046 } | |
3047 osthread->sr.set_suspend_action(SR_NONE); | |
3048 return true; | |
3049 } | |
3050 else { | |
3051 osthread->sr.set_suspend_action(SR_NONE); | |
3052 return false; | |
3053 } | |
3054 } | |
3055 | |
3056 static void do_resume(OSThread* osthread) { | |
3057 assert(osthread->sr.is_suspended(), "thread should be suspended"); | |
3058 osthread->sr.set_suspend_action(SR_CONTINUE); | |
3059 | |
3060 int status = pthread_kill(osthread->pthread_id(), SR_signum); | |
3061 assert_status(status == 0, status, "pthread_kill"); | |
3062 // check status and wait unit notified of resumption | |
3063 if (status == 0) { | |
3064 for (int i = 0; osthread->sr.is_suspended(); i++) { | |
3065 os::yield_all(i); | |
3066 } | |
3067 } | |
3068 osthread->sr.set_suspend_action(SR_NONE); | |
3069 } | |
3070 | |
3071 //////////////////////////////////////////////////////////////////////////////// | |
3072 // interrupt support | |
3073 | |
3074 void os::interrupt(Thread* thread) { | |
3075 assert(Thread::current() == thread || Threads_lock->owned_by_self(), | |
3076 "possibility of dangling Thread pointer"); | |
3077 | |
3078 OSThread* osthread = thread->osthread(); | |
3079 | |
3080 if (!osthread->interrupted()) { | |
3081 osthread->set_interrupted(true); | |
3082 // More than one thread can get here with the same value of osthread, | |
3083 // resulting in multiple notifications. We do, however, want the store | |
3084 // to interrupted() to be visible to other threads before we execute unpark(). | |
3085 OrderAccess::fence(); | |
3086 ParkEvent * const slp = thread->_SleepEvent ; | |
3087 if (slp != NULL) slp->unpark() ; | |
3088 } | |
3089 | |
3090 // For JSR166. Unpark even if interrupt status already was set | |
3091 if (thread->is_Java_thread()) | |
3092 ((JavaThread*)thread)->parker()->unpark(); | |
3093 | |
3094 ParkEvent * ev = thread->_ParkEvent ; | |
3095 if (ev != NULL) ev->unpark() ; | |
3096 | |
3097 } | |
3098 | |
3099 bool os::is_interrupted(Thread* thread, bool clear_interrupted) { | |
3100 assert(Thread::current() == thread || Threads_lock->owned_by_self(), | |
3101 "possibility of dangling Thread pointer"); | |
3102 | |
3103 OSThread* osthread = thread->osthread(); | |
3104 | |
3105 bool interrupted = osthread->interrupted(); | |
3106 | |
3107 if (interrupted && clear_interrupted) { | |
3108 osthread->set_interrupted(false); | |
3109 // consider thread->_SleepEvent->reset() ... optional optimization | |
3110 } | |
3111 | |
3112 return interrupted; | |
3113 } | |
3114 | |
3115 /////////////////////////////////////////////////////////////////////////////////// | |
3116 // signal handling (except suspend/resume) | |
3117 | |
3118 // This routine may be used by user applications as a "hook" to catch signals. | |
3119 // The user-defined signal handler must pass unrecognized signals to this | |
3120 // routine, and if it returns true (non-zero), then the signal handler must | |
3121 // return immediately. If the flag "abort_if_unrecognized" is true, then this | |
3122 // routine will never retun false (zero), but instead will execute a VM panic | |
3123 // routine kill the process. | |
3124 // | |
3125 // If this routine returns false, it is OK to call it again. This allows | |
3126 // the user-defined signal handler to perform checks either before or after | |
3127 // the VM performs its own checks. Naturally, the user code would be making | |
3128 // a serious error if it tried to handle an exception (such as a null check | |
3129 // or breakpoint) that the VM was generating for its own correct operation. | |
3130 // | |
3131 // This routine may recognize any of the following kinds of signals: | |
3132 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. | |
3133 // It should be consulted by handlers for any of those signals. | |
3134 // | |
3135 // The caller of this routine must pass in the three arguments supplied | |
3136 // to the function referred to in the "sa_sigaction" (not the "sa_handler") | |
3137 // field of the structure passed to sigaction(). This routine assumes that | |
3138 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. | |
3139 // | |
3140 // Note that the VM will print warnings if it detects conflicting signal | |
3141 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". | |
3142 // | |
3143 extern "C" int | |
3144 JVM_handle_linux_signal(int signo, siginfo_t* siginfo, | |
3145 void* ucontext, int abort_if_unrecognized); | |
3146 | |
3147 void signalHandler(int sig, siginfo_t* info, void* uc) { | |
3148 assert(info != NULL && uc != NULL, "it must be old kernel"); | |
3149 JVM_handle_linux_signal(sig, info, uc, true); | |
3150 } | |
3151 | |
3152 | |
3153 // This boolean allows users to forward their own non-matching signals | |
3154 // to JVM_handle_linux_signal, harmlessly. | |
3155 bool os::Linux::signal_handlers_are_installed = false; | |
3156 | |
3157 // For signal-chaining | |
3158 struct sigaction os::Linux::sigact[MAXSIGNUM]; | |
3159 unsigned int os::Linux::sigs = 0; | |
3160 bool os::Linux::libjsig_is_loaded = false; | |
3161 typedef struct sigaction *(*get_signal_t)(int); | |
3162 get_signal_t os::Linux::get_signal_action = NULL; | |
3163 | |
3164 struct sigaction* os::Linux::get_chained_signal_action(int sig) { | |
3165 struct sigaction *actp = NULL; | |
3166 | |
3167 if (libjsig_is_loaded) { | |
3168 // Retrieve the old signal handler from libjsig | |
3169 actp = (*get_signal_action)(sig); | |
3170 } | |
3171 if (actp == NULL) { | |
3172 // Retrieve the preinstalled signal handler from jvm | |
3173 actp = get_preinstalled_handler(sig); | |
3174 } | |
3175 | |
3176 return actp; | |
3177 } | |
3178 | |
3179 static bool call_chained_handler(struct sigaction *actp, int sig, | |
3180 siginfo_t *siginfo, void *context) { | |
3181 // Call the old signal handler | |
3182 if (actp->sa_handler == SIG_DFL) { | |
3183 // It's more reasonable to let jvm treat it as an unexpected exception | |
3184 // instead of taking the default action. | |
3185 return false; | |
3186 } else if (actp->sa_handler != SIG_IGN) { | |
3187 if ((actp->sa_flags & SA_NODEFER) == 0) { | |
3188 // automaticlly block the signal | |
3189 sigaddset(&(actp->sa_mask), sig); | |
3190 } | |
3191 | |
3192 sa_handler_t hand; | |
3193 sa_sigaction_t sa; | |
3194 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; | |
3195 // retrieve the chained handler | |
3196 if (siginfo_flag_set) { | |
3197 sa = actp->sa_sigaction; | |
3198 } else { | |
3199 hand = actp->sa_handler; | |
3200 } | |
3201 | |
3202 if ((actp->sa_flags & SA_RESETHAND) != 0) { | |
3203 actp->sa_handler = SIG_DFL; | |
3204 } | |
3205 | |
3206 // try to honor the signal mask | |
3207 sigset_t oset; | |
3208 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); | |
3209 | |
3210 // call into the chained handler | |
3211 if (siginfo_flag_set) { | |
3212 (*sa)(sig, siginfo, context); | |
3213 } else { | |
3214 (*hand)(sig); | |
3215 } | |
3216 | |
3217 // restore the signal mask | |
3218 pthread_sigmask(SIG_SETMASK, &oset, 0); | |
3219 } | |
3220 // Tell jvm's signal handler the signal is taken care of. | |
3221 return true; | |
3222 } | |
3223 | |
3224 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) { | |
3225 bool chained = false; | |
3226 // signal-chaining | |
3227 if (UseSignalChaining) { | |
3228 struct sigaction *actp = get_chained_signal_action(sig); | |
3229 if (actp != NULL) { | |
3230 chained = call_chained_handler(actp, sig, siginfo, context); | |
3231 } | |
3232 } | |
3233 return chained; | |
3234 } | |
3235 | |
3236 struct sigaction* os::Linux::get_preinstalled_handler(int sig) { | |
3237 if ((( (unsigned int)1 << sig ) & sigs) != 0) { | |
3238 return &sigact[sig]; | |
3239 } | |
3240 return NULL; | |
3241 } | |
3242 | |
3243 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { | |
3244 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); | |
3245 sigact[sig] = oldAct; | |
3246 sigs |= (unsigned int)1 << sig; | |
3247 } | |
3248 | |
3249 // for diagnostic | |
3250 int os::Linux::sigflags[MAXSIGNUM]; | |
3251 | |
3252 int os::Linux::get_our_sigflags(int sig) { | |
3253 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); | |
3254 return sigflags[sig]; | |
3255 } | |
3256 | |
3257 void os::Linux::set_our_sigflags(int sig, int flags) { | |
3258 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); | |
3259 sigflags[sig] = flags; | |
3260 } | |
3261 | |
3262 void os::Linux::set_signal_handler(int sig, bool set_installed) { | |
3263 // Check for overwrite. | |
3264 struct sigaction oldAct; | |
3265 sigaction(sig, (struct sigaction*)NULL, &oldAct); | |
3266 | |
3267 void* oldhand = oldAct.sa_sigaction | |
3268 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) | |
3269 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); | |
3270 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && | |
3271 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && | |
3272 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { | |
3273 if (AllowUserSignalHandlers || !set_installed) { | |
3274 // Do not overwrite; user takes responsibility to forward to us. | |
3275 return; | |
3276 } else if (UseSignalChaining) { | |
3277 // save the old handler in jvm | |
3278 save_preinstalled_handler(sig, oldAct); | |
3279 // libjsig also interposes the sigaction() call below and saves the | |
3280 // old sigaction on it own. | |
3281 } else { | |
3282 fatal2("Encountered unexpected pre-existing sigaction handler %#lx for signal %d.", (long)oldhand, sig); | |
3283 } | |
3284 } | |
3285 | |
3286 struct sigaction sigAct; | |
3287 sigfillset(&(sigAct.sa_mask)); | |
3288 sigAct.sa_handler = SIG_DFL; | |
3289 if (!set_installed) { | |
3290 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; | |
3291 } else { | |
3292 sigAct.sa_sigaction = signalHandler; | |
3293 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; | |
3294 } | |
3295 // Save flags, which are set by ours | |
3296 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range"); | |
3297 sigflags[sig] = sigAct.sa_flags; | |
3298 | |
3299 int ret = sigaction(sig, &sigAct, &oldAct); | |
3300 assert(ret == 0, "check"); | |
3301 | |
3302 void* oldhand2 = oldAct.sa_sigaction | |
3303 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) | |
3304 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); | |
3305 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); | |
3306 } | |
3307 | |
3308 // install signal handlers for signals that HotSpot needs to | |
3309 // handle in order to support Java-level exception handling. | |
3310 | |
3311 void os::Linux::install_signal_handlers() { | |
3312 if (!signal_handlers_are_installed) { | |
3313 signal_handlers_are_installed = true; | |
3314 | |
3315 // signal-chaining | |
3316 typedef void (*signal_setting_t)(); | |
3317 signal_setting_t begin_signal_setting = NULL; | |
3318 signal_setting_t end_signal_setting = NULL; | |
3319 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, | |
3320 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); | |
3321 if (begin_signal_setting != NULL) { | |
3322 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, | |
3323 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); | |
3324 get_signal_action = CAST_TO_FN_PTR(get_signal_t, | |
3325 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); | |
3326 libjsig_is_loaded = true; | |
3327 assert(UseSignalChaining, "should enable signal-chaining"); | |
3328 } | |
3329 if (libjsig_is_loaded) { | |
3330 // Tell libjsig jvm is setting signal handlers | |
3331 (*begin_signal_setting)(); | |
3332 } | |
3333 | |
3334 set_signal_handler(SIGSEGV, true); | |
3335 set_signal_handler(SIGPIPE, true); | |
3336 set_signal_handler(SIGBUS, true); | |
3337 set_signal_handler(SIGILL, true); | |
3338 set_signal_handler(SIGFPE, true); | |
3339 set_signal_handler(SIGXFSZ, true); | |
3340 | |
3341 if (libjsig_is_loaded) { | |
3342 // Tell libjsig jvm finishes setting signal handlers | |
3343 (*end_signal_setting)(); | |
3344 } | |
3345 | |
3346 // We don't activate signal checker if libjsig is in place, we trust ourselves | |
3347 // and if UserSignalHandler is installed all bets are off | |
3348 if (CheckJNICalls) { | |
3349 if (libjsig_is_loaded) { | |
3350 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); | |
3351 check_signals = false; | |
3352 } | |
3353 if (AllowUserSignalHandlers) { | |
3354 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); | |
3355 check_signals = false; | |
3356 } | |
3357 } | |
3358 } | |
3359 } | |
3360 | |
3361 // This is the fastest way to get thread cpu time on Linux. | |
3362 // Returns cpu time (user+sys) for any thread, not only for current. | |
3363 // POSIX compliant clocks are implemented in the kernels 2.6.16+. | |
3364 // It might work on 2.6.10+ with a special kernel/glibc patch. | |
3365 // For reference, please, see IEEE Std 1003.1-2004: | |
3366 // http://www.unix.org/single_unix_specification | |
3367 | |
3368 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) { | |
3369 struct timespec tp; | |
3370 int rc = os::Linux::clock_gettime(clockid, &tp); | |
3371 assert(rc == 0, "clock_gettime is expected to return 0 code"); | |
3372 | |
3373 return (tp.tv_sec * SEC_IN_NANOSECS) + tp.tv_nsec; | |
3374 } | |
3375 | |
3376 ///// | |
3377 // glibc on Linux platform uses non-documented flag | |
3378 // to indicate, that some special sort of signal | |
3379 // trampoline is used. | |
3380 // We will never set this flag, and we should | |
3381 // ignore this flag in our diagnostic | |
3382 #ifdef SIGNIFICANT_SIGNAL_MASK | |
3383 #undef SIGNIFICANT_SIGNAL_MASK | |
3384 #endif | |
3385 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) | |
3386 | |
3387 static const char* get_signal_handler_name(address handler, | |
3388 char* buf, int buflen) { | |
3389 int offset; | |
3390 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); | |
3391 if (found) { | |
3392 // skip directory names | |
3393 const char *p1, *p2; | |
3394 p1 = buf; | |
3395 size_t len = strlen(os::file_separator()); | |
3396 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; | |
3397 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); | |
3398 } else { | |
3399 jio_snprintf(buf, buflen, PTR_FORMAT, handler); | |
3400 } | |
3401 return buf; | |
3402 } | |
3403 | |
3404 static void print_signal_handler(outputStream* st, int sig, | |
3405 char* buf, size_t buflen) { | |
3406 struct sigaction sa; | |
3407 | |
3408 sigaction(sig, NULL, &sa); | |
3409 | |
3410 // See comment for SIGNIFICANT_SIGNAL_MASK define | |
3411 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; | |
3412 | |
3413 st->print("%s: ", os::exception_name(sig, buf, buflen)); | |
3414 | |
3415 address handler = (sa.sa_flags & SA_SIGINFO) | |
3416 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) | |
3417 : CAST_FROM_FN_PTR(address, sa.sa_handler); | |
3418 | |
3419 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { | |
3420 st->print("SIG_DFL"); | |
3421 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { | |
3422 st->print("SIG_IGN"); | |
3423 } else { | |
3424 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); | |
3425 } | |
3426 | |
3427 st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask); | |
3428 | |
3429 address rh = VMError::get_resetted_sighandler(sig); | |
3430 // May be, handler was resetted by VMError? | |
3431 if(rh != NULL) { | |
3432 handler = rh; | |
3433 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; | |
3434 } | |
3435 | |
3436 st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags); | |
3437 | |
3438 // Check: is it our handler? | |
3439 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || | |
3440 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { | |
3441 // It is our signal handler | |
3442 // check for flags, reset system-used one! | |
3443 if((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) { | |
3444 st->print( | |
3445 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", | |
3446 os::Linux::get_our_sigflags(sig)); | |
3447 } | |
3448 } | |
3449 st->cr(); | |
3450 } | |
3451 | |
3452 | |
3453 #define DO_SIGNAL_CHECK(sig) \ | |
3454 if (!sigismember(&check_signal_done, sig)) \ | |
3455 os::Linux::check_signal_handler(sig) | |
3456 | |
3457 // This method is a periodic task to check for misbehaving JNI applications | |
3458 // under CheckJNI, we can add any periodic checks here | |
3459 | |
3460 void os::run_periodic_checks() { | |
3461 | |
3462 if (check_signals == false) return; | |
3463 | |
3464 // SEGV and BUS if overridden could potentially prevent | |
3465 // generation of hs*.log in the event of a crash, debugging | |
3466 // such a case can be very challenging, so we absolutely | |
3467 // check the following for a good measure: | |
3468 DO_SIGNAL_CHECK(SIGSEGV); | |
3469 DO_SIGNAL_CHECK(SIGILL); | |
3470 DO_SIGNAL_CHECK(SIGFPE); | |
3471 DO_SIGNAL_CHECK(SIGBUS); | |
3472 DO_SIGNAL_CHECK(SIGPIPE); | |
3473 DO_SIGNAL_CHECK(SIGXFSZ); | |
3474 | |
3475 | |
3476 // ReduceSignalUsage allows the user to override these handlers | |
3477 // see comments at the very top and jvm_solaris.h | |
3478 if (!ReduceSignalUsage) { | |
3479 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); | |
3480 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); | |
3481 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); | |
3482 DO_SIGNAL_CHECK(BREAK_SIGNAL); | |
3483 } | |
3484 | |
3485 DO_SIGNAL_CHECK(SR_signum); | |
3486 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL); | |
3487 } | |
3488 | |
3489 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); | |
3490 | |
3491 static os_sigaction_t os_sigaction = NULL; | |
3492 | |
3493 void os::Linux::check_signal_handler(int sig) { | |
3494 char buf[O_BUFLEN]; | |
3495 address jvmHandler = NULL; | |
3496 | |
3497 | |
3498 struct sigaction act; | |
3499 if (os_sigaction == NULL) { | |
3500 // only trust the default sigaction, in case it has been interposed | |
3501 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); | |
3502 if (os_sigaction == NULL) return; | |
3503 } | |
3504 | |
3505 os_sigaction(sig, (struct sigaction*)NULL, &act); | |
3506 | |
3507 | |
3508 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; | |
3509 | |
3510 address thisHandler = (act.sa_flags & SA_SIGINFO) | |
3511 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) | |
3512 : CAST_FROM_FN_PTR(address, act.sa_handler) ; | |
3513 | |
3514 | |
3515 switch(sig) { | |
3516 case SIGSEGV: | |
3517 case SIGBUS: | |
3518 case SIGFPE: | |
3519 case SIGPIPE: | |
3520 case SIGILL: | |
3521 case SIGXFSZ: | |
3522 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); | |
3523 break; | |
3524 | |
3525 case SHUTDOWN1_SIGNAL: | |
3526 case SHUTDOWN2_SIGNAL: | |
3527 case SHUTDOWN3_SIGNAL: | |
3528 case BREAK_SIGNAL: | |
3529 jvmHandler = (address)user_handler(); | |
3530 break; | |
3531 | |
3532 case INTERRUPT_SIGNAL: | |
3533 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL); | |
3534 break; | |
3535 | |
3536 default: | |
3537 if (sig == SR_signum) { | |
3538 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); | |
3539 } else { | |
3540 return; | |
3541 } | |
3542 break; | |
3543 } | |
3544 | |
3545 if (thisHandler != jvmHandler) { | |
3546 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); | |
3547 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); | |
3548 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); | |
3549 // No need to check this sig any longer | |
3550 sigaddset(&check_signal_done, sig); | |
3551 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) { | |
3552 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); | |
3553 tty->print("expected:" PTR32_FORMAT, os::Linux::get_our_sigflags(sig)); | |
3554 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags); | |
3555 // No need to check this sig any longer | |
3556 sigaddset(&check_signal_done, sig); | |
3557 } | |
3558 | |
3559 // Dump all the signal | |
3560 if (sigismember(&check_signal_done, sig)) { | |
3561 print_signal_handlers(tty, buf, O_BUFLEN); | |
3562 } | |
3563 } | |
3564 | |
3565 extern void report_error(char* file_name, int line_no, char* title, char* format, ...); | |
3566 | |
3567 extern bool signal_name(int signo, char* buf, size_t len); | |
3568 | |
3569 const char* os::exception_name(int exception_code, char* buf, size_t size) { | |
3570 if (0 < exception_code && exception_code <= SIGRTMAX) { | |
3571 // signal | |
3572 if (!signal_name(exception_code, buf, size)) { | |
3573 jio_snprintf(buf, size, "SIG%d", exception_code); | |
3574 } | |
3575 return buf; | |
3576 } else { | |
3577 return NULL; | |
3578 } | |
3579 } | |
3580 | |
3581 // this is called _before_ the most of global arguments have been parsed | |
3582 void os::init(void) { | |
3583 char dummy; /* used to get a guess on initial stack address */ | |
3584 // first_hrtime = gethrtime(); | |
3585 | |
3586 // With LinuxThreads the JavaMain thread pid (primordial thread) | |
3587 // is different than the pid of the java launcher thread. | |
3588 // So, on Linux, the launcher thread pid is passed to the VM | |
3589 // via the sun.java.launcher.pid property. | |
3590 // Use this property instead of getpid() if it was correctly passed. | |
3591 // See bug 6351349. | |
3592 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid(); | |
3593 | |
3594 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid(); | |
3595 | |
3596 clock_tics_per_sec = sysconf(_SC_CLK_TCK); | |
3597 | |
3598 init_random(1234567); | |
3599 | |
3600 ThreadCritical::initialize(); | |
3601 | |
3602 Linux::set_page_size(sysconf(_SC_PAGESIZE)); | |
3603 if (Linux::page_size() == -1) { | |
3604 fatal1("os_linux.cpp: os::init: sysconf failed (%s)", strerror(errno)); | |
3605 } | |
3606 init_page_sizes((size_t) Linux::page_size()); | |
3607 | |
3608 Linux::initialize_system_info(); | |
3609 | |
3610 // main_thread points to the aboriginal thread | |
3611 Linux::_main_thread = pthread_self(); | |
3612 | |
3613 Linux::clock_init(); | |
3614 initial_time_count = os::elapsed_counter(); | |
242 | 3615 pthread_mutex_init(&dl_mutex, NULL); |
0 | 3616 } |
3617 | |
3618 // To install functions for atexit system call | |
3619 extern "C" { | |
3620 static void perfMemory_exit_helper() { | |
3621 perfMemory_exit(); | |
3622 } | |
3623 } | |
3624 | |
3625 // this is called _after_ the global arguments have been parsed | |
3626 jint os::init_2(void) | |
3627 { | |
3628 Linux::fast_thread_clock_init(); | |
3629 | |
3630 // Allocate a single page and mark it as readable for safepoint polling | |
3631 address polling_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); | |
3632 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" ); | |
3633 | |
3634 os::set_polling_page( polling_page ); | |
3635 | |
3636 #ifndef PRODUCT | |
3637 if(Verbose && PrintMiscellaneous) | |
3638 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page); | |
3639 #endif | |
3640 | |
3641 if (!UseMembar) { | |
3642 address mem_serialize_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); | |
3643 guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page"); | |
3644 os::set_memory_serialize_page( mem_serialize_page ); | |
3645 | |
3646 #ifndef PRODUCT | |
3647 if(Verbose && PrintMiscellaneous) | |
3648 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page); | |
3649 #endif | |
3650 } | |
3651 | |
3652 FLAG_SET_DEFAULT(UseLargePages, os::large_page_init()); | |
3653 | |
3654 // initialize suspend/resume support - must do this before signal_sets_init() | |
3655 if (SR_initialize() != 0) { | |
3656 perror("SR_initialize failed"); | |
3657 return JNI_ERR; | |
3658 } | |
3659 | |
3660 Linux::signal_sets_init(); | |
3661 Linux::install_signal_handlers(); | |
3662 | |
3663 size_t threadStackSizeInBytes = ThreadStackSize * K; | |
3664 if (threadStackSizeInBytes != 0 && | |
3665 threadStackSizeInBytes < Linux::min_stack_allowed) { | |
3666 tty->print_cr("\nThe stack size specified is too small, " | |
3667 "Specify at least %dk", | |
3668 Linux::min_stack_allowed / K); | |
3669 return JNI_ERR; | |
3670 } | |
3671 | |
3672 // Make the stack size a multiple of the page size so that | |
3673 // the yellow/red zones can be guarded. | |
3674 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, | |
3675 vm_page_size())); | |
3676 | |
3677 Linux::capture_initial_stack(JavaThread::stack_size_at_create()); | |
3678 | |
3679 Linux::libpthread_init(); | |
3680 if (PrintMiscellaneous && (Verbose || WizardMode)) { | |
3681 tty->print_cr("[HotSpot is running with %s, %s(%s)]\n", | |
3682 Linux::glibc_version(), Linux::libpthread_version(), | |
3683 Linux::is_floating_stack() ? "floating stack" : "fixed stack"); | |
3684 } | |
3685 | |
141 | 3686 if (UseNUMA) { |
3687 Linux::libnuma_init(); | |
3688 } | |
3689 | |
0 | 3690 if (MaxFDLimit) { |
3691 // set the number of file descriptors to max. print out error | |
3692 // if getrlimit/setrlimit fails but continue regardless. | |
3693 struct rlimit nbr_files; | |
3694 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); | |
3695 if (status != 0) { | |
3696 if (PrintMiscellaneous && (Verbose || WizardMode)) | |
3697 perror("os::init_2 getrlimit failed"); | |
3698 } else { | |
3699 nbr_files.rlim_cur = nbr_files.rlim_max; | |
3700 status = setrlimit(RLIMIT_NOFILE, &nbr_files); | |
3701 if (status != 0) { | |
3702 if (PrintMiscellaneous && (Verbose || WizardMode)) | |
3703 perror("os::init_2 setrlimit failed"); | |
3704 } | |
3705 } | |
3706 } | |
3707 | |
3708 // Initialize lock used to serialize thread creation (see os::create_thread) | |
3709 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); | |
3710 | |
3711 // Initialize HPI. | |
3712 jint hpi_result = hpi::initialize(); | |
3713 if (hpi_result != JNI_OK) { | |
3714 tty->print_cr("There was an error trying to initialize the HPI library."); | |
3715 return hpi_result; | |
3716 } | |
3717 | |
3718 // at-exit methods are called in the reverse order of their registration. | |
3719 // atexit functions are called on return from main or as a result of a | |
3720 // call to exit(3C). There can be only 32 of these functions registered | |
3721 // and atexit() does not set errno. | |
3722 | |
3723 if (PerfAllowAtExitRegistration) { | |
3724 // only register atexit functions if PerfAllowAtExitRegistration is set. | |
3725 // atexit functions can be delayed until process exit time, which | |
3726 // can be problematic for embedded VM situations. Embedded VMs should | |
3727 // call DestroyJavaVM() to assure that VM resources are released. | |
3728 | |
3729 // note: perfMemory_exit_helper atexit function may be removed in | |
3730 // the future if the appropriate cleanup code can be added to the | |
3731 // VM_Exit VMOperation's doit method. | |
3732 if (atexit(perfMemory_exit_helper) != 0) { | |
3733 warning("os::init2 atexit(perfMemory_exit_helper) failed"); | |
3734 } | |
3735 } | |
3736 | |
3737 // initialize thread priority policy | |
3738 prio_init(); | |
3739 | |
3740 return JNI_OK; | |
3741 } | |
3742 | |
3743 // Mark the polling page as unreadable | |
3744 void os::make_polling_page_unreadable(void) { | |
3745 if( !guard_memory((char*)_polling_page, Linux::page_size()) ) | |
3746 fatal("Could not disable polling page"); | |
3747 }; | |
3748 | |
3749 // Mark the polling page as readable | |
3750 void os::make_polling_page_readable(void) { | |
237
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|
3751 if( !linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) { |
0 | 3752 fatal("Could not enable polling page"); |
237
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|
3753 } |
0 | 3754 }; |
3755 | |
3756 int os::active_processor_count() { | |
3757 // Linux doesn't yet have a (official) notion of processor sets, | |
3758 // so just return the number of online processors. | |
3759 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); | |
3760 assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check"); | |
3761 return online_cpus; | |
3762 } | |
3763 | |
3764 bool os::distribute_processes(uint length, uint* distribution) { | |
3765 // Not yet implemented. | |
3766 return false; | |
3767 } | |
3768 | |
3769 bool os::bind_to_processor(uint processor_id) { | |
3770 // Not yet implemented. | |
3771 return false; | |
3772 } | |
3773 | |
3774 /// | |
3775 | |
3776 // Suspends the target using the signal mechanism and then grabs the PC before | |
3777 // resuming the target. Used by the flat-profiler only | |
3778 ExtendedPC os::get_thread_pc(Thread* thread) { | |
3779 // Make sure that it is called by the watcher for the VMThread | |
3780 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); | |
3781 assert(thread->is_VM_thread(), "Can only be called for VMThread"); | |
3782 | |
3783 ExtendedPC epc; | |
3784 | |
3785 OSThread* osthread = thread->osthread(); | |
3786 if (do_suspend(osthread)) { | |
3787 if (osthread->ucontext() != NULL) { | |
3788 epc = os::Linux::ucontext_get_pc(osthread->ucontext()); | |
3789 } else { | |
3790 // NULL context is unexpected, double-check this is the VMThread | |
3791 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); | |
3792 } | |
3793 do_resume(osthread); | |
3794 } | |
3795 // failure means pthread_kill failed for some reason - arguably this is | |
3796 // a fatal problem, but such problems are ignored elsewhere | |
3797 | |
3798 return epc; | |
3799 } | |
3800 | |
3801 int os::Linux::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime) | |
3802 { | |
3803 if (is_NPTL()) { | |
3804 return pthread_cond_timedwait(_cond, _mutex, _abstime); | |
3805 } else { | |
3806 #ifndef IA64 | |
3807 // 6292965: LinuxThreads pthread_cond_timedwait() resets FPU control | |
3808 // word back to default 64bit precision if condvar is signaled. Java | |
3809 // wants 53bit precision. Save and restore current value. | |
3810 int fpu = get_fpu_control_word(); | |
3811 #endif // IA64 | |
3812 int status = pthread_cond_timedwait(_cond, _mutex, _abstime); | |
3813 #ifndef IA64 | |
3814 set_fpu_control_word(fpu); | |
3815 #endif // IA64 | |
3816 return status; | |
3817 } | |
3818 } | |
3819 | |
3820 //////////////////////////////////////////////////////////////////////////////// | |
3821 // debug support | |
3822 | |
3823 #ifndef PRODUCT | |
3824 static address same_page(address x, address y) { | |
3825 int page_bits = -os::vm_page_size(); | |
3826 if ((intptr_t(x) & page_bits) == (intptr_t(y) & page_bits)) | |
3827 return x; | |
3828 else if (x > y) | |
3829 return (address)(intptr_t(y) | ~page_bits) + 1; | |
3830 else | |
3831 return (address)(intptr_t(y) & page_bits); | |
3832 } | |
3833 | |
3834 bool os::find(address addr) { | |
3835 Dl_info dlinfo; | |
3836 memset(&dlinfo, 0, sizeof(dlinfo)); | |
3837 if (dladdr(addr, &dlinfo)) { | |
3838 tty->print(PTR_FORMAT ": ", addr); | |
3839 if (dlinfo.dli_sname != NULL) { | |
3840 tty->print("%s+%#x", dlinfo.dli_sname, | |
3841 addr - (intptr_t)dlinfo.dli_saddr); | |
3842 } else if (dlinfo.dli_fname) { | |
3843 tty->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase); | |
3844 } else { | |
3845 tty->print("<absolute address>"); | |
3846 } | |
3847 if (dlinfo.dli_fname) { | |
3848 tty->print(" in %s", dlinfo.dli_fname); | |
3849 } | |
3850 if (dlinfo.dli_fbase) { | |
3851 tty->print(" at " PTR_FORMAT, dlinfo.dli_fbase); | |
3852 } | |
3853 tty->cr(); | |
3854 | |
3855 if (Verbose) { | |
3856 // decode some bytes around the PC | |
3857 address begin = same_page(addr-40, addr); | |
3858 address end = same_page(addr+40, addr); | |
3859 address lowest = (address) dlinfo.dli_sname; | |
3860 if (!lowest) lowest = (address) dlinfo.dli_fbase; | |
3861 if (begin < lowest) begin = lowest; | |
3862 Dl_info dlinfo2; | |
3863 if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr | |
3864 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) | |
3865 end = (address) dlinfo2.dli_saddr; | |
3866 Disassembler::decode(begin, end); | |
3867 } | |
3868 return true; | |
3869 } | |
3870 return false; | |
3871 } | |
3872 | |
3873 #endif | |
3874 | |
3875 //////////////////////////////////////////////////////////////////////////////// | |
3876 // misc | |
3877 | |
3878 // This does not do anything on Linux. This is basically a hook for being | |
3879 // able to use structured exception handling (thread-local exception filters) | |
3880 // on, e.g., Win32. | |
3881 void | |
3882 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method, | |
3883 JavaCallArguments* args, Thread* thread) { | |
3884 f(value, method, args, thread); | |
3885 } | |
3886 | |
3887 void os::print_statistics() { | |
3888 } | |
3889 | |
3890 int os::message_box(const char* title, const char* message) { | |
3891 int i; | |
3892 fdStream err(defaultStream::error_fd()); | |
3893 for (i = 0; i < 78; i++) err.print_raw("="); | |
3894 err.cr(); | |
3895 err.print_raw_cr(title); | |
3896 for (i = 0; i < 78; i++) err.print_raw("-"); | |
3897 err.cr(); | |
3898 err.print_raw_cr(message); | |
3899 for (i = 0; i < 78; i++) err.print_raw("="); | |
3900 err.cr(); | |
3901 | |
3902 char buf[16]; | |
3903 // Prevent process from exiting upon "read error" without consuming all CPU | |
3904 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } | |
3905 | |
3906 return buf[0] == 'y' || buf[0] == 'Y'; | |
3907 } | |
3908 | |
3909 int os::stat(const char *path, struct stat *sbuf) { | |
3910 char pathbuf[MAX_PATH]; | |
3911 if (strlen(path) > MAX_PATH - 1) { | |
3912 errno = ENAMETOOLONG; | |
3913 return -1; | |
3914 } | |
3915 hpi::native_path(strcpy(pathbuf, path)); | |
3916 return ::stat(pathbuf, sbuf); | |
3917 } | |
3918 | |
3919 bool os::check_heap(bool force) { | |
3920 return true; | |
3921 } | |
3922 | |
3923 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) { | |
3924 return ::vsnprintf(buf, count, format, args); | |
3925 } | |
3926 | |
3927 // Is a (classpath) directory empty? | |
3928 bool os::dir_is_empty(const char* path) { | |
3929 DIR *dir = NULL; | |
3930 struct dirent *ptr; | |
3931 | |
3932 dir = opendir(path); | |
3933 if (dir == NULL) return true; | |
3934 | |
3935 /* Scan the directory */ | |
3936 bool result = true; | |
3937 char buf[sizeof(struct dirent) + MAX_PATH]; | |
3938 while (result && (ptr = ::readdir(dir)) != NULL) { | |
3939 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { | |
3940 result = false; | |
3941 } | |
3942 } | |
3943 closedir(dir); | |
3944 return result; | |
3945 } | |
3946 | |
3947 // create binary file, rewriting existing file if required | |
3948 int os::create_binary_file(const char* path, bool rewrite_existing) { | |
3949 int oflags = O_WRONLY | O_CREAT; | |
3950 if (!rewrite_existing) { | |
3951 oflags |= O_EXCL; | |
3952 } | |
3953 return ::open64(path, oflags, S_IREAD | S_IWRITE); | |
3954 } | |
3955 | |
3956 // return current position of file pointer | |
3957 jlong os::current_file_offset(int fd) { | |
3958 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR); | |
3959 } | |
3960 | |
3961 // move file pointer to the specified offset | |
3962 jlong os::seek_to_file_offset(int fd, jlong offset) { | |
3963 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET); | |
3964 } | |
3965 | |
3966 // Map a block of memory. | |
3967 char* os::map_memory(int fd, const char* file_name, size_t file_offset, | |
3968 char *addr, size_t bytes, bool read_only, | |
3969 bool allow_exec) { | |
3970 int prot; | |
3971 int flags; | |
3972 | |
3973 if (read_only) { | |
3974 prot = PROT_READ; | |
3975 flags = MAP_SHARED; | |
3976 } else { | |
3977 prot = PROT_READ | PROT_WRITE; | |
3978 flags = MAP_PRIVATE; | |
3979 } | |
3980 | |
3981 if (allow_exec) { | |
3982 prot |= PROT_EXEC; | |
3983 } | |
3984 | |
3985 if (addr != NULL) { | |
3986 flags |= MAP_FIXED; | |
3987 } | |
3988 | |
3989 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, | |
3990 fd, file_offset); | |
3991 if (mapped_address == MAP_FAILED) { | |
3992 return NULL; | |
3993 } | |
3994 return mapped_address; | |
3995 } | |
3996 | |
3997 | |
3998 // Remap a block of memory. | |
3999 char* os::remap_memory(int fd, const char* file_name, size_t file_offset, | |
4000 char *addr, size_t bytes, bool read_only, | |
4001 bool allow_exec) { | |
4002 // same as map_memory() on this OS | |
4003 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, | |
4004 allow_exec); | |
4005 } | |
4006 | |
4007 | |
4008 // Unmap a block of memory. | |
4009 bool os::unmap_memory(char* addr, size_t bytes) { | |
4010 return munmap(addr, bytes) == 0; | |
4011 } | |
4012 | |
4013 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); | |
4014 | |
4015 static clockid_t thread_cpu_clockid(Thread* thread) { | |
4016 pthread_t tid = thread->osthread()->pthread_id(); | |
4017 clockid_t clockid; | |
4018 | |
4019 // Get thread clockid | |
4020 int rc = os::Linux::pthread_getcpuclockid(tid, &clockid); | |
4021 assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code"); | |
4022 return clockid; | |
4023 } | |
4024 | |
4025 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) | |
4026 // are used by JVM M&M and JVMTI to get user+sys or user CPU time | |
4027 // of a thread. | |
4028 // | |
4029 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns | |
4030 // the fast estimate available on the platform. | |
4031 | |
4032 jlong os::current_thread_cpu_time() { | |
4033 if (os::Linux::supports_fast_thread_cpu_time()) { | |
4034 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); | |
4035 } else { | |
4036 // return user + sys since the cost is the same | |
4037 return slow_thread_cpu_time(Thread::current(), true /* user + sys */); | |
4038 } | |
4039 } | |
4040 | |
4041 jlong os::thread_cpu_time(Thread* thread) { | |
4042 // consistent with what current_thread_cpu_time() returns | |
4043 if (os::Linux::supports_fast_thread_cpu_time()) { | |
4044 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); | |
4045 } else { | |
4046 return slow_thread_cpu_time(thread, true /* user + sys */); | |
4047 } | |
4048 } | |
4049 | |
4050 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { | |
4051 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { | |
4052 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); | |
4053 } else { | |
4054 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); | |
4055 } | |
4056 } | |
4057 | |
4058 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { | |
4059 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { | |
4060 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); | |
4061 } else { | |
4062 return slow_thread_cpu_time(thread, user_sys_cpu_time); | |
4063 } | |
4064 } | |
4065 | |
4066 // | |
4067 // -1 on error. | |
4068 // | |
4069 | |
4070 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { | |
4071 static bool proc_pid_cpu_avail = true; | |
4072 static bool proc_task_unchecked = true; | |
4073 static const char *proc_stat_path = "/proc/%d/stat"; | |
4074 pid_t tid = thread->osthread()->thread_id(); | |
4075 int i; | |
4076 char *s; | |
4077 char stat[2048]; | |
4078 int statlen; | |
4079 char proc_name[64]; | |
4080 int count; | |
4081 long sys_time, user_time; | |
4082 char string[64]; | |
4083 int idummy; | |
4084 long ldummy; | |
4085 FILE *fp; | |
4086 | |
4087 // We first try accessing /proc/<pid>/cpu since this is faster to | |
4088 // process. If this file is not present (linux kernels 2.5 and above) | |
4089 // then we open /proc/<pid>/stat. | |
4090 if ( proc_pid_cpu_avail ) { | |
4091 sprintf(proc_name, "/proc/%d/cpu", tid); | |
4092 fp = fopen(proc_name, "r"); | |
4093 if ( fp != NULL ) { | |
4094 count = fscanf( fp, "%s %lu %lu\n", string, &user_time, &sys_time); | |
4095 fclose(fp); | |
4096 if ( count != 3 ) return -1; | |
4097 | |
4098 if (user_sys_cpu_time) { | |
4099 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); | |
4100 } else { | |
4101 return (jlong)user_time * (1000000000 / clock_tics_per_sec); | |
4102 } | |
4103 } | |
4104 else proc_pid_cpu_avail = false; | |
4105 } | |
4106 | |
4107 // The /proc/<tid>/stat aggregates per-process usage on | |
4108 // new Linux kernels 2.6+ where NPTL is supported. | |
4109 // The /proc/self/task/<tid>/stat still has the per-thread usage. | |
4110 // See bug 6328462. | |
4111 // There can be no directory /proc/self/task on kernels 2.4 with NPTL | |
4112 // and possibly in some other cases, so we check its availability. | |
4113 if (proc_task_unchecked && os::Linux::is_NPTL()) { | |
4114 // This is executed only once | |
4115 proc_task_unchecked = false; | |
4116 fp = fopen("/proc/self/task", "r"); | |
4117 if (fp != NULL) { | |
4118 proc_stat_path = "/proc/self/task/%d/stat"; | |
4119 fclose(fp); | |
4120 } | |
4121 } | |
4122 | |
4123 sprintf(proc_name, proc_stat_path, tid); | |
4124 fp = fopen(proc_name, "r"); | |
4125 if ( fp == NULL ) return -1; | |
4126 statlen = fread(stat, 1, 2047, fp); | |
4127 stat[statlen] = '\0'; | |
4128 fclose(fp); | |
4129 | |
4130 // Skip pid and the command string. Note that we could be dealing with | |
4131 // weird command names, e.g. user could decide to rename java launcher | |
4132 // to "java 1.4.2 :)", then the stat file would look like | |
4133 // 1234 (java 1.4.2 :)) R ... ... | |
4134 // We don't really need to know the command string, just find the last | |
4135 // occurrence of ")" and then start parsing from there. See bug 4726580. | |
4136 s = strrchr(stat, ')'); | |
4137 i = 0; | |
4138 if (s == NULL ) return -1; | |
4139 | |
4140 // Skip blank chars | |
4141 do s++; while (isspace(*s)); | |
4142 | |
4143 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", | |
4144 &idummy, &idummy, &idummy, &idummy, &idummy, &idummy, | |
4145 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, | |
4146 &user_time, &sys_time); | |
4147 if ( count != 13 ) return -1; | |
4148 if (user_sys_cpu_time) { | |
4149 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); | |
4150 } else { | |
4151 return (jlong)user_time * (1000000000 / clock_tics_per_sec); | |
4152 } | |
4153 } | |
4154 | |
4155 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { | |
4156 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits | |
4157 info_ptr->may_skip_backward = false; // elapsed time not wall time | |
4158 info_ptr->may_skip_forward = false; // elapsed time not wall time | |
4159 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned | |
4160 } | |
4161 | |
4162 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { | |
4163 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits | |
4164 info_ptr->may_skip_backward = false; // elapsed time not wall time | |
4165 info_ptr->may_skip_forward = false; // elapsed time not wall time | |
4166 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned | |
4167 } | |
4168 | |
4169 bool os::is_thread_cpu_time_supported() { | |
4170 return true; | |
4171 } | |
4172 | |
4173 // System loadavg support. Returns -1 if load average cannot be obtained. | |
4174 // Linux doesn't yet have a (official) notion of processor sets, | |
4175 // so just return the system wide load average. | |
4176 int os::loadavg(double loadavg[], int nelem) { | |
4177 return ::getloadavg(loadavg, nelem); | |
4178 } | |
4179 | |
4180 void os::pause() { | |
4181 char filename[MAX_PATH]; | |
4182 if (PauseAtStartupFile && PauseAtStartupFile[0]) { | |
4183 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile); | |
4184 } else { | |
4185 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); | |
4186 } | |
4187 | |
4188 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); | |
4189 if (fd != -1) { | |
4190 struct stat buf; | |
4191 close(fd); | |
4192 while (::stat(filename, &buf) == 0) { | |
4193 (void)::poll(NULL, 0, 100); | |
4194 } | |
4195 } else { | |
4196 jio_fprintf(stderr, | |
4197 "Could not open pause file '%s', continuing immediately.\n", filename); | |
4198 } | |
4199 } | |
4200 | |
4201 extern "C" { | |
4202 | |
4203 /** | |
4204 * NOTE: the following code is to keep the green threads code | |
4205 * in the libjava.so happy. Once the green threads is removed, | |
4206 * these code will no longer be needed. | |
4207 */ | |
4208 int | |
4209 jdk_waitpid(pid_t pid, int* status, int options) { | |
4210 return waitpid(pid, status, options); | |
4211 } | |
4212 | |
4213 int | |
4214 fork1() { | |
4215 return fork(); | |
4216 } | |
4217 | |
4218 int | |
4219 jdk_sem_init(sem_t *sem, int pshared, unsigned int value) { | |
4220 return sem_init(sem, pshared, value); | |
4221 } | |
4222 | |
4223 int | |
4224 jdk_sem_post(sem_t *sem) { | |
4225 return sem_post(sem); | |
4226 } | |
4227 | |
4228 int | |
4229 jdk_sem_wait(sem_t *sem) { | |
4230 return sem_wait(sem); | |
4231 } | |
4232 | |
4233 int | |
4234 jdk_pthread_sigmask(int how , const sigset_t* newmask, sigset_t* oldmask) { | |
4235 return pthread_sigmask(how , newmask, oldmask); | |
4236 } | |
4237 | |
4238 } | |
4239 | |
4240 // Refer to the comments in os_solaris.cpp park-unpark. | |
4241 // | |
4242 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can | |
4243 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable. | |
4244 // For specifics regarding the bug see GLIBC BUGID 261237 : | |
4245 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html. | |
4246 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future | |
4247 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar | |
4248 // is used. (The simple C test-case provided in the GLIBC bug report manifests the | |
4249 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos() | |
4250 // and monitorenter when we're using 1-0 locking. All those operations may result in | |
4251 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version | |
4252 // of libpthread avoids the problem, but isn't practical. | |
4253 // | |
4254 // Possible remedies: | |
4255 // | |
4256 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work. | |
4257 // This is palliative and probabilistic, however. If the thread is preempted | |
4258 // between the call to compute_abstime() and pthread_cond_timedwait(), more | |
4259 // than the minimum period may have passed, and the abstime may be stale (in the | |
4260 // past) resultin in a hang. Using this technique reduces the odds of a hang | |
4261 // but the JVM is still vulnerable, particularly on heavily loaded systems. | |
4262 // | |
4263 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead | |
4264 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set | |
4265 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo) | |
4266 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant | |
4267 // thread. | |
4268 // | |
4269 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread | |
4270 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing | |
4271 // a timeout request to the chron thread and then blocking via pthread_cond_wait(). | |
4272 // This also works well. In fact it avoids kernel-level scalability impediments | |
4273 // on certain platforms that don't handle lots of active pthread_cond_timedwait() | |
4274 // timers in a graceful fashion. | |
4275 // | |
4276 // 4. When the abstime value is in the past it appears that control returns | |
4277 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt. | |
4278 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we | |
4279 // can avoid the problem by reinitializing the condvar -- by cond_destroy() | |
4280 // followed by cond_init() -- after all calls to pthread_cond_timedwait(). | |
4281 // It may be possible to avoid reinitialization by checking the return | |
4282 // value from pthread_cond_timedwait(). In addition to reinitializing the | |
4283 // condvar we must establish the invariant that cond_signal() is only called | |
4284 // within critical sections protected by the adjunct mutex. This prevents | |
4285 // cond_signal() from "seeing" a condvar that's in the midst of being | |
4286 // reinitialized or that is corrupt. Sadly, this invariant obviates the | |
4287 // desirable signal-after-unlock optimization that avoids futile context switching. | |
4288 // | |
4289 // I'm also concerned that some versions of NTPL might allocate an auxilliary | |
4290 // structure when a condvar is used or initialized. cond_destroy() would | |
4291 // release the helper structure. Our reinitialize-after-timedwait fix | |
4292 // put excessive stress on malloc/free and locks protecting the c-heap. | |
4293 // | |
4294 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag. | |
4295 // It may be possible to refine (4) by checking the kernel and NTPL verisons | |
4296 // and only enabling the work-around for vulnerable environments. | |
4297 | |
4298 // utility to compute the abstime argument to timedwait: | |
4299 // millis is the relative timeout time | |
4300 // abstime will be the absolute timeout time | |
4301 // TODO: replace compute_abstime() with unpackTime() | |
4302 | |
4303 static struct timespec* compute_abstime(timespec* abstime, jlong millis) { | |
4304 if (millis < 0) millis = 0; | |
4305 struct timeval now; | |
4306 int status = gettimeofday(&now, NULL); | |
4307 assert(status == 0, "gettimeofday"); | |
4308 jlong seconds = millis / 1000; | |
4309 millis %= 1000; | |
4310 if (seconds > 50000000) { // see man cond_timedwait(3T) | |
4311 seconds = 50000000; | |
4312 } | |
4313 abstime->tv_sec = now.tv_sec + seconds; | |
4314 long usec = now.tv_usec + millis * 1000; | |
4315 if (usec >= 1000000) { | |
4316 abstime->tv_sec += 1; | |
4317 usec -= 1000000; | |
4318 } | |
4319 abstime->tv_nsec = usec * 1000; | |
4320 return abstime; | |
4321 } | |
4322 | |
4323 | |
4324 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately. | |
4325 // Conceptually TryPark() should be equivalent to park(0). | |
4326 | |
4327 int os::PlatformEvent::TryPark() { | |
4328 for (;;) { | |
4329 const int v = _Event ; | |
4330 guarantee ((v == 0) || (v == 1), "invariant") ; | |
4331 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ; | |
4332 } | |
4333 } | |
4334 | |
4335 void os::PlatformEvent::park() { // AKA "down()" | |
4336 // Invariant: Only the thread associated with the Event/PlatformEvent | |
4337 // may call park(). | |
4338 // TODO: assert that _Assoc != NULL or _Assoc == Self | |
4339 int v ; | |
4340 for (;;) { | |
4341 v = _Event ; | |
4342 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; | |
4343 } | |
4344 guarantee (v >= 0, "invariant") ; | |
4345 if (v == 0) { | |
4346 // Do this the hard way by blocking ... | |
4347 int status = pthread_mutex_lock(_mutex); | |
4348 assert_status(status == 0, status, "mutex_lock"); | |
4349 guarantee (_nParked == 0, "invariant") ; | |
4350 ++ _nParked ; | |
4351 while (_Event < 0) { | |
4352 status = pthread_cond_wait(_cond, _mutex); | |
4353 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ... | |
4354 // Treat this the same as if the wait was interrupted | |
4355 if (status == ETIME) { status = EINTR; } | |
4356 assert_status(status == 0 || status == EINTR, status, "cond_wait"); | |
4357 } | |
4358 -- _nParked ; | |
4359 | |
4360 // In theory we could move the ST of 0 into _Event past the unlock(), | |
4361 // but then we'd need a MEMBAR after the ST. | |
4362 _Event = 0 ; | |
4363 status = pthread_mutex_unlock(_mutex); | |
4364 assert_status(status == 0, status, "mutex_unlock"); | |
4365 } | |
4366 guarantee (_Event >= 0, "invariant") ; | |
4367 } | |
4368 | |
4369 int os::PlatformEvent::park(jlong millis) { | |
4370 guarantee (_nParked == 0, "invariant") ; | |
4371 | |
4372 int v ; | |
4373 for (;;) { | |
4374 v = _Event ; | |
4375 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ; | |
4376 } | |
4377 guarantee (v >= 0, "invariant") ; | |
4378 if (v != 0) return OS_OK ; | |
4379 | |
4380 // We do this the hard way, by blocking the thread. | |
4381 // Consider enforcing a minimum timeout value. | |
4382 struct timespec abst; | |
4383 compute_abstime(&abst, millis); | |
4384 | |
4385 int ret = OS_TIMEOUT; | |
4386 int status = pthread_mutex_lock(_mutex); | |
4387 assert_status(status == 0, status, "mutex_lock"); | |
4388 guarantee (_nParked == 0, "invariant") ; | |
4389 ++_nParked ; | |
4390 | |
4391 // Object.wait(timo) will return because of | |
4392 // (a) notification | |
4393 // (b) timeout | |
4394 // (c) thread.interrupt | |
4395 // | |
4396 // Thread.interrupt and object.notify{All} both call Event::set. | |
4397 // That is, we treat thread.interrupt as a special case of notification. | |
4398 // The underlying Solaris implementation, cond_timedwait, admits | |
4399 // spurious/premature wakeups, but the JLS/JVM spec prevents the | |
4400 // JVM from making those visible to Java code. As such, we must | |
4401 // filter out spurious wakeups. We assume all ETIME returns are valid. | |
4402 // | |
4403 // TODO: properly differentiate simultaneous notify+interrupt. | |
4404 // In that case, we should propagate the notify to another waiter. | |
4405 | |
4406 while (_Event < 0) { | |
4407 status = os::Linux::safe_cond_timedwait(_cond, _mutex, &abst); | |
4408 if (status != 0 && WorkAroundNPTLTimedWaitHang) { | |
4409 pthread_cond_destroy (_cond); | |
4410 pthread_cond_init (_cond, NULL) ; | |
4411 } | |
4412 assert_status(status == 0 || status == EINTR || | |
4413 status == ETIME || status == ETIMEDOUT, | |
4414 status, "cond_timedwait"); | |
4415 if (!FilterSpuriousWakeups) break ; // previous semantics | |
4416 if (status == ETIME || status == ETIMEDOUT) break ; | |
4417 // We consume and ignore EINTR and spurious wakeups. | |
4418 } | |
4419 --_nParked ; | |
4420 if (_Event >= 0) { | |
4421 ret = OS_OK; | |
4422 } | |
4423 _Event = 0 ; | |
4424 status = pthread_mutex_unlock(_mutex); | |
4425 assert_status(status == 0, status, "mutex_unlock"); | |
4426 assert (_nParked == 0, "invariant") ; | |
4427 return ret; | |
4428 } | |
4429 | |
4430 void os::PlatformEvent::unpark() { | |
4431 int v, AnyWaiters ; | |
4432 for (;;) { | |
4433 v = _Event ; | |
4434 if (v > 0) { | |
4435 // The LD of _Event could have reordered or be satisfied | |
4436 // by a read-aside from this processor's write buffer. | |
4437 // To avoid problems execute a barrier and then | |
4438 // ratify the value. | |
4439 OrderAccess::fence() ; | |
4440 if (_Event == v) return ; | |
4441 continue ; | |
4442 } | |
4443 if (Atomic::cmpxchg (v+1, &_Event, v) == v) break ; | |
4444 } | |
4445 if (v < 0) { | |
4446 // Wait for the thread associated with the event to vacate | |
4447 int status = pthread_mutex_lock(_mutex); | |
4448 assert_status(status == 0, status, "mutex_lock"); | |
4449 AnyWaiters = _nParked ; | |
4450 assert (AnyWaiters == 0 || AnyWaiters == 1, "invariant") ; | |
4451 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) { | |
4452 AnyWaiters = 0 ; | |
4453 pthread_cond_signal (_cond); | |
4454 } | |
4455 status = pthread_mutex_unlock(_mutex); | |
4456 assert_status(status == 0, status, "mutex_unlock"); | |
4457 if (AnyWaiters != 0) { | |
4458 status = pthread_cond_signal(_cond); | |
4459 assert_status(status == 0, status, "cond_signal"); | |
4460 } | |
4461 } | |
4462 | |
4463 // Note that we signal() _after dropping the lock for "immortal" Events. | |
4464 // This is safe and avoids a common class of futile wakeups. In rare | |
4465 // circumstances this can cause a thread to return prematurely from | |
4466 // cond_{timed}wait() but the spurious wakeup is benign and the victim will | |
4467 // simply re-test the condition and re-park itself. | |
4468 } | |
4469 | |
4470 | |
4471 // JSR166 | |
4472 // ------------------------------------------------------- | |
4473 | |
4474 /* | |
4475 * The solaris and linux implementations of park/unpark are fairly | |
4476 * conservative for now, but can be improved. They currently use a | |
4477 * mutex/condvar pair, plus a a count. | |
4478 * Park decrements count if > 0, else does a condvar wait. Unpark | |
4479 * sets count to 1 and signals condvar. Only one thread ever waits | |
4480 * on the condvar. Contention seen when trying to park implies that someone | |
4481 * is unparking you, so don't wait. And spurious returns are fine, so there | |
4482 * is no need to track notifications. | |
4483 */ | |
4484 | |
4485 | |
4486 #define NANOSECS_PER_SEC 1000000000 | |
4487 #define NANOSECS_PER_MILLISEC 1000000 | |
4488 #define MAX_SECS 100000000 | |
4489 /* | |
4490 * This code is common to linux and solaris and will be moved to a | |
4491 * common place in dolphin. | |
4492 * | |
4493 * The passed in time value is either a relative time in nanoseconds | |
4494 * or an absolute time in milliseconds. Either way it has to be unpacked | |
4495 * into suitable seconds and nanoseconds components and stored in the | |
4496 * given timespec structure. | |
4497 * Given time is a 64-bit value and the time_t used in the timespec is only | |
4498 * a signed-32-bit value (except on 64-bit Linux) we have to watch for | |
4499 * overflow if times way in the future are given. Further on Solaris versions | |
4500 * prior to 10 there is a restriction (see cond_timedwait) that the specified | |
4501 * number of seconds, in abstime, is less than current_time + 100,000,000. | |
4502 * As it will be 28 years before "now + 100000000" will overflow we can | |
4503 * ignore overflow and just impose a hard-limit on seconds using the value | |
4504 * of "now + 100,000,000". This places a limit on the timeout of about 3.17 | |
4505 * years from "now". | |
4506 */ | |
4507 | |
4508 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time) { | |
4509 assert (time > 0, "convertTime"); | |
4510 | |
4511 struct timeval now; | |
4512 int status = gettimeofday(&now, NULL); | |
4513 assert(status == 0, "gettimeofday"); | |
4514 | |
4515 time_t max_secs = now.tv_sec + MAX_SECS; | |
4516 | |
4517 if (isAbsolute) { | |
4518 jlong secs = time / 1000; | |
4519 if (secs > max_secs) { | |
4520 absTime->tv_sec = max_secs; | |
4521 } | |
4522 else { | |
4523 absTime->tv_sec = secs; | |
4524 } | |
4525 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC; | |
4526 } | |
4527 else { | |
4528 jlong secs = time / NANOSECS_PER_SEC; | |
4529 if (secs >= MAX_SECS) { | |
4530 absTime->tv_sec = max_secs; | |
4531 absTime->tv_nsec = 0; | |
4532 } | |
4533 else { | |
4534 absTime->tv_sec = now.tv_sec + secs; | |
4535 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000; | |
4536 if (absTime->tv_nsec >= NANOSECS_PER_SEC) { | |
4537 absTime->tv_nsec -= NANOSECS_PER_SEC; | |
4538 ++absTime->tv_sec; // note: this must be <= max_secs | |
4539 } | |
4540 } | |
4541 } | |
4542 assert(absTime->tv_sec >= 0, "tv_sec < 0"); | |
4543 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs"); | |
4544 assert(absTime->tv_nsec >= 0, "tv_nsec < 0"); | |
4545 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec"); | |
4546 } | |
4547 | |
4548 void Parker::park(bool isAbsolute, jlong time) { | |
4549 // Optional fast-path check: | |
4550 // Return immediately if a permit is available. | |
4551 if (_counter > 0) { | |
4552 _counter = 0 ; | |
4553 return ; | |
4554 } | |
4555 | |
4556 Thread* thread = Thread::current(); | |
4557 assert(thread->is_Java_thread(), "Must be JavaThread"); | |
4558 JavaThread *jt = (JavaThread *)thread; | |
4559 | |
4560 // Optional optimization -- avoid state transitions if there's an interrupt pending. | |
4561 // Check interrupt before trying to wait | |
4562 if (Thread::is_interrupted(thread, false)) { | |
4563 return; | |
4564 } | |
4565 | |
4566 // Next, demultiplex/decode time arguments | |
4567 timespec absTime; | |
4568 if (time < 0) { // don't wait at all | |
4569 return; | |
4570 } | |
4571 if (time > 0) { | |
4572 unpackTime(&absTime, isAbsolute, time); | |
4573 } | |
4574 | |
4575 | |
4576 // Enter safepoint region | |
4577 // Beware of deadlocks such as 6317397. | |
4578 // The per-thread Parker:: mutex is a classic leaf-lock. | |
4579 // In particular a thread must never block on the Threads_lock while | |
4580 // holding the Parker:: mutex. If safepoints are pending both the | |
4581 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock. | |
4582 ThreadBlockInVM tbivm(jt); | |
4583 | |
4584 // Don't wait if cannot get lock since interference arises from | |
4585 // unblocking. Also. check interrupt before trying wait | |
4586 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) { | |
4587 return; | |
4588 } | |
4589 | |
4590 int status ; | |
4591 if (_counter > 0) { // no wait needed | |
4592 _counter = 0; | |
4593 status = pthread_mutex_unlock(_mutex); | |
4594 assert (status == 0, "invariant") ; | |
4595 return; | |
4596 } | |
4597 | |
4598 #ifdef ASSERT | |
4599 // Don't catch signals while blocked; let the running threads have the signals. | |
4600 // (This allows a debugger to break into the running thread.) | |
4601 sigset_t oldsigs; | |
4602 sigset_t* allowdebug_blocked = os::Linux::allowdebug_blocked_signals(); | |
4603 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs); | |
4604 #endif | |
4605 | |
4606 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */); | |
4607 jt->set_suspend_equivalent(); | |
4608 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() | |
4609 | |
4610 if (time == 0) { | |
4611 status = pthread_cond_wait (_cond, _mutex) ; | |
4612 } else { | |
4613 status = os::Linux::safe_cond_timedwait (_cond, _mutex, &absTime) ; | |
4614 if (status != 0 && WorkAroundNPTLTimedWaitHang) { | |
4615 pthread_cond_destroy (_cond) ; | |
4616 pthread_cond_init (_cond, NULL); | |
4617 } | |
4618 } | |
4619 assert_status(status == 0 || status == EINTR || | |
4620 status == ETIME || status == ETIMEDOUT, | |
4621 status, "cond_timedwait"); | |
4622 | |
4623 #ifdef ASSERT | |
4624 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL); | |
4625 #endif | |
4626 | |
4627 _counter = 0 ; | |
4628 status = pthread_mutex_unlock(_mutex) ; | |
4629 assert_status(status == 0, status, "invariant") ; | |
4630 // If externally suspended while waiting, re-suspend | |
4631 if (jt->handle_special_suspend_equivalent_condition()) { | |
4632 jt->java_suspend_self(); | |
4633 } | |
4634 | |
4635 } | |
4636 | |
4637 void Parker::unpark() { | |
4638 int s, status ; | |
4639 status = pthread_mutex_lock(_mutex); | |
4640 assert (status == 0, "invariant") ; | |
4641 s = _counter; | |
4642 _counter = 1; | |
4643 if (s < 1) { | |
4644 if (WorkAroundNPTLTimedWaitHang) { | |
4645 status = pthread_cond_signal (_cond) ; | |
4646 assert (status == 0, "invariant") ; | |
4647 status = pthread_mutex_unlock(_mutex); | |
4648 assert (status == 0, "invariant") ; | |
4649 } else { | |
4650 status = pthread_mutex_unlock(_mutex); | |
4651 assert (status == 0, "invariant") ; | |
4652 status = pthread_cond_signal (_cond) ; | |
4653 assert (status == 0, "invariant") ; | |
4654 } | |
4655 } else { | |
4656 pthread_mutex_unlock(_mutex); | |
4657 assert (status == 0, "invariant") ; | |
4658 } | |
4659 } | |
4660 | |
4661 | |
4662 extern char** environ; | |
4663 | |
4664 #ifndef __NR_fork | |
4665 #define __NR_fork IA32_ONLY(2) IA64_ONLY(not defined) AMD64_ONLY(57) | |
4666 #endif | |
4667 | |
4668 #ifndef __NR_execve | |
4669 #define __NR_execve IA32_ONLY(11) IA64_ONLY(1033) AMD64_ONLY(59) | |
4670 #endif | |
4671 | |
4672 // Run the specified command in a separate process. Return its exit value, | |
4673 // or -1 on failure (e.g. can't fork a new process). | |
4674 // Unlike system(), this function can be called from signal handler. It | |
4675 // doesn't block SIGINT et al. | |
4676 int os::fork_and_exec(char* cmd) { | |
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4677 const char * argv[4] = {"sh", "-c", cmd, NULL}; |
0 | 4678 |
4679 // fork() in LinuxThreads/NPTL is not async-safe. It needs to run | |
4680 // pthread_atfork handlers and reset pthread library. All we need is a | |
4681 // separate process to execve. Make a direct syscall to fork process. | |
4682 // On IA64 there's no fork syscall, we have to use fork() and hope for | |
4683 // the best... | |
4684 pid_t pid = NOT_IA64(syscall(__NR_fork);) | |
4685 IA64_ONLY(fork();) | |
4686 | |
4687 if (pid < 0) { | |
4688 // fork failed | |
4689 return -1; | |
4690 | |
4691 } else if (pid == 0) { | |
4692 // child process | |
4693 | |
4694 // execve() in LinuxThreads will call pthread_kill_other_threads_np() | |
4695 // first to kill every thread on the thread list. Because this list is | |
4696 // not reset by fork() (see notes above), execve() will instead kill | |
4697 // every thread in the parent process. We know this is the only thread | |
4698 // in the new process, so make a system call directly. | |
4699 // IA64 should use normal execve() from glibc to match the glibc fork() | |
4700 // above. | |
4701 NOT_IA64(syscall(__NR_execve, "/bin/sh", argv, environ);) | |
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4702 IA64_ONLY(execve("/bin/sh", (char* const*)argv, environ);) |
0 | 4703 |
4704 // execve failed | |
4705 _exit(-1); | |
4706 | |
4707 } else { | |
4708 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't | |
4709 // care about the actual exit code, for now. | |
4710 | |
4711 int status; | |
4712 | |
4713 // Wait for the child process to exit. This returns immediately if | |
4714 // the child has already exited. */ | |
4715 while (waitpid(pid, &status, 0) < 0) { | |
4716 switch (errno) { | |
4717 case ECHILD: return 0; | |
4718 case EINTR: break; | |
4719 default: return -1; | |
4720 } | |
4721 } | |
4722 | |
4723 if (WIFEXITED(status)) { | |
4724 // The child exited normally; get its exit code. | |
4725 return WEXITSTATUS(status); | |
4726 } else if (WIFSIGNALED(status)) { | |
4727 // The child exited because of a signal | |
4728 // The best value to return is 0x80 + signal number, | |
4729 // because that is what all Unix shells do, and because | |
4730 // it allows callers to distinguish between process exit and | |
4731 // process death by signal. | |
4732 return 0x80 + WTERMSIG(status); | |
4733 } else { | |
4734 // Unknown exit code; pass it through | |
4735 return status; | |
4736 } | |
4737 } | |
4738 } |