Mercurial > hg > truffle
annotate src/os/linux/vm/jsig.c @ 9010:08a16c26907f
MX_TESTFILE environment variable can be used to specify (and preserve) the test list file used by 'mx unittest'.
This is useful when wanting to run the command under gdb.
| author | Doug Simon <doug.simon@oracle.com> |
|---|---|
| date | Thu, 11 Apr 2013 21:40:52 +0200 |
| parents | f95d63e2154a |
| children | 732af649bc3a |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 1972 | 2 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 25 /* CopyrightVersion 1.2 */ | |
| 26 | |
| 27 /* This is a special library that should be loaded before libc & | |
| 28 * libthread to interpose the signal handler installation functions: | |
| 29 * sigaction(), signal(), sigset(). | |
| 30 * Used for signal-chaining. See RFE 4381843. | |
| 31 */ | |
| 32 | |
| 33 #include <signal.h> | |
| 34 #include <dlfcn.h> | |
| 35 #include <pthread.h> | |
| 36 #include <stdio.h> | |
| 37 #include <stdlib.h> | |
| 38 | |
| 39 #define bool int | |
| 40 #define true 1 | |
| 41 #define false 0 | |
| 42 | |
| 43 #define MAXSIGNUM 32 | |
| 44 #define MASK(sig) ((unsigned int)1 << sig) | |
| 45 | |
| 46 static struct sigaction sact[MAXSIGNUM]; /* saved signal handlers */ | |
| 47 static unsigned int jvmsigs = 0; /* signals used by jvm */ | |
| 48 | |
| 49 /* used to synchronize the installation of signal handlers */ | |
| 50 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; | |
| 51 static pthread_cond_t cond = PTHREAD_COND_INITIALIZER; | |
| 52 static pthread_t tid = 0; | |
| 53 | |
| 54 typedef void (*sa_handler_t)(int); | |
| 55 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); | |
| 56 typedef sa_handler_t (*signal_t)(int, sa_handler_t); | |
| 57 typedef int (*sigaction_t)(int, const struct sigaction *, struct sigaction *); | |
| 58 | |
| 59 static signal_t os_signal = 0; /* os's version of signal()/sigset() */ | |
| 60 static sigaction_t os_sigaction = 0; /* os's version of sigaction() */ | |
| 61 | |
| 62 static bool jvm_signal_installing = false; | |
| 63 static bool jvm_signal_installed = false; | |
| 64 | |
| 65 static void signal_lock() { | |
| 66 pthread_mutex_lock(&mutex); | |
| 67 /* When the jvm is installing its set of signal handlers, threads | |
| 68 * other than the jvm thread should wait */ | |
| 69 if (jvm_signal_installing) { | |
| 70 if (tid != pthread_self()) { | |
| 71 pthread_cond_wait(&cond, &mutex); | |
| 72 } | |
| 73 } | |
| 74 } | |
| 75 | |
| 76 static void signal_unlock() { | |
| 77 pthread_mutex_unlock(&mutex); | |
| 78 } | |
| 79 | |
| 80 static sa_handler_t call_os_signal(int sig, sa_handler_t disp, | |
| 81 bool is_sigset) { | |
| 82 if (os_signal == NULL) { | |
| 83 if (!is_sigset) { | |
| 84 os_signal = (signal_t)dlsym(RTLD_NEXT, "signal"); | |
| 85 } else { | |
| 86 os_signal = (signal_t)dlsym(RTLD_NEXT, "sigset"); | |
| 87 } | |
| 88 if (os_signal == NULL) { | |
| 89 printf("%s\n", dlerror()); | |
| 90 exit(0); | |
| 91 } | |
| 92 } | |
| 93 return (*os_signal)(sig, disp); | |
| 94 } | |
| 95 | |
| 96 static void save_signal_handler(int sig, sa_handler_t disp) { | |
| 97 sigset_t set; | |
| 98 sact[sig].sa_handler = disp; | |
| 99 sigemptyset(&set); | |
| 100 sact[sig].sa_mask = set; | |
| 101 sact[sig].sa_flags = 0; | |
| 102 } | |
| 103 | |
| 104 static sa_handler_t set_signal(int sig, sa_handler_t disp, bool is_sigset) { | |
| 105 sa_handler_t oldhandler; | |
| 106 bool sigused; | |
| 107 | |
| 108 signal_lock(); | |
| 109 | |
| 110 sigused = (MASK(sig) & jvmsigs) != 0; | |
| 111 if (jvm_signal_installed && sigused) { | |
| 112 /* jvm has installed its signal handler for this signal. */ | |
| 113 /* Save the handler. Don't really install it. */ | |
| 114 oldhandler = sact[sig].sa_handler; | |
| 115 save_signal_handler(sig, disp); | |
| 116 | |
| 117 signal_unlock(); | |
| 118 return oldhandler; | |
| 119 } else if (jvm_signal_installing) { | |
| 120 /* jvm is installing its signal handlers. Install the new | |
| 121 * handlers and save the old ones. jvm uses sigaction(). | |
| 122 * Leave the piece here just in case. */ | |
| 123 oldhandler = call_os_signal(sig, disp, is_sigset); | |
| 124 save_signal_handler(sig, oldhandler); | |
| 125 | |
| 126 /* Record the signals used by jvm */ | |
| 127 jvmsigs |= MASK(sig); | |
| 128 | |
| 129 signal_unlock(); | |
| 130 return oldhandler; | |
| 131 } else { | |
| 132 /* jvm has no relation with this signal (yet). Install the | |
| 133 * the handler. */ | |
| 134 oldhandler = call_os_signal(sig, disp, is_sigset); | |
| 135 | |
| 136 signal_unlock(); | |
| 137 return oldhandler; | |
| 138 } | |
| 139 } | |
| 140 | |
| 141 sa_handler_t signal(int sig, sa_handler_t disp) { | |
| 142 return set_signal(sig, disp, false); | |
| 143 } | |
| 144 | |
| 145 sa_handler_t sigset(int sig, sa_handler_t disp) { | |
| 146 return set_signal(sig, disp, true); | |
| 147 } | |
| 148 | |
| 149 static int call_os_sigaction(int sig, const struct sigaction *act, | |
| 150 struct sigaction *oact) { | |
| 151 if (os_sigaction == NULL) { | |
| 152 os_sigaction = (sigaction_t)dlsym(RTLD_NEXT, "sigaction"); | |
| 153 if (os_sigaction == NULL) { | |
| 154 printf("%s\n", dlerror()); | |
| 155 exit(0); | |
| 156 } | |
| 157 } | |
| 158 return (*os_sigaction)(sig, act, oact); | |
| 159 } | |
| 160 | |
| 161 int sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { | |
| 162 int res; | |
| 163 bool sigused; | |
| 164 struct sigaction oldAct; | |
| 165 | |
| 166 signal_lock(); | |
| 167 | |
| 168 sigused = (MASK(sig) & jvmsigs) != 0; | |
| 169 if (jvm_signal_installed && sigused) { | |
| 170 /* jvm has installed its signal handler for this signal. */ | |
| 171 /* Save the handler. Don't really install it. */ | |
| 172 if (oact != NULL) { | |
| 173 *oact = sact[sig]; | |
| 174 } | |
| 175 if (act != NULL) { | |
| 176 sact[sig] = *act; | |
| 177 } | |
| 178 | |
| 179 signal_unlock(); | |
| 180 return 0; | |
| 181 } else if (jvm_signal_installing) { | |
| 182 /* jvm is installing its signal handlers. Install the new | |
| 183 * handlers and save the old ones. */ | |
| 184 res = call_os_sigaction(sig, act, &oldAct); | |
| 185 sact[sig] = oldAct; | |
| 186 if (oact != NULL) { | |
| 187 *oact = oldAct; | |
| 188 } | |
| 189 | |
| 190 /* Record the signals used by jvm */ | |
| 191 jvmsigs |= MASK(sig); | |
| 192 | |
| 193 signal_unlock(); | |
| 194 return res; | |
| 195 } else { | |
| 196 /* jvm has no relation with this signal (yet). Install the | |
| 197 * the handler. */ | |
| 198 res = call_os_sigaction(sig, act, oact); | |
| 199 | |
| 200 signal_unlock(); | |
| 201 return res; | |
| 202 } | |
| 203 } | |
| 204 | |
| 205 /* The three functions for the jvm to call into */ | |
| 206 void JVM_begin_signal_setting() { | |
| 207 signal_lock(); | |
| 208 jvm_signal_installing = true; | |
| 209 tid = pthread_self(); | |
| 210 signal_unlock(); | |
| 211 } | |
| 212 | |
| 213 void JVM_end_signal_setting() { | |
| 214 signal_lock(); | |
| 215 jvm_signal_installed = true; | |
| 216 jvm_signal_installing = false; | |
| 217 pthread_cond_broadcast(&cond); | |
| 218 signal_unlock(); | |
| 219 } | |
| 220 | |
| 221 struct sigaction *JVM_get_signal_action(int sig) { | |
| 222 /* Does race condition make sense here? */ | |
| 223 if ((MASK(sig) & jvmsigs) != 0) { | |
| 224 return &sact[sig]; | |
| 225 } | |
| 226 return NULL; | |
| 227 } |