< prev index next >
src/java.base/solaris/native/libjsig/jsig.c
Print this page
@@ -1,7 +1,8 @@
/*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2015 SAP SE. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
@@ -20,139 +21,141 @@
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
-/* CopyrightVersion 1.2 */
-
/* This is a special library that should be loaded before libc &
* libthread to interpose the signal handler installation functions:
* sigaction(), signal(), sigset().
* Used for signal-chaining. See RFE 4381843.
*/
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <signal.h>
#include <dlfcn.h>
-#include <thread.h>
-#include <synch.h>
-#include "jvm_md.h"
-
-#define bool int
-#define true 1
-#define false 0
-
-static struct sigaction *sact = (struct sigaction *)NULL; /* saved signal handlers */
-static sigset_t jvmsigs;
-
-/* used to synchronize the installation of signal handlers */
-static mutex_t mutex = DEFAULTMUTEX;
-static cond_t cond = DEFAULTCV;
-static thread_t tid = 0;
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#if (__STDC_VERSION__ >= 199901L)
+ #include <stdbool.h>
+#else
+ #define bool int
+ #define true 1
+ #define false 0
+#endif
+
+static struct sigaction sact[NSIG]; /* saved signal handlers */
+static sigset_t jvmsigs; /* Signals used by jvm. */
+
+#ifdef MACOSX
+static __thread bool reentry = false; /* prevent reentry deadlock (per-thread) */
+#endif
+
+/* Used to synchronize the installation of signal handlers. */
+static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+static pthread_t tid = 0;
typedef void (*sa_handler_t)(int);
typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
-typedef sa_handler_t (*signal_t)(int, sa_handler_t);
+typedef sa_handler_t (*signal_function_t)(int, sa_handler_t);
typedef int (*sigaction_t)(int, const struct sigaction *, struct sigaction *);
-static signal_t os_signal = 0; /* os's version of signal()/sigset() */
+static signal_function_t os_signal = 0; /* os's version of signal()/sigset() */
static sigaction_t os_sigaction = 0; /* os's version of sigaction() */
static bool jvm_signal_installing = false;
static bool jvm_signal_installed = false;
-
-/* assume called within signal_lock */
-static void allocate_sact() {
- size_t maxsignum;
- maxsignum = SIGRTMAX;
- if (sact == NULL) {
- sact = (struct sigaction *)malloc((maxsignum+1) * (size_t)sizeof(struct sigaction));
- memset(sact, 0, (maxsignum+1) * (size_t)sizeof(struct sigaction));
- }
-
- if (sact == NULL) {
- printf("%s\n", "libjsig.so unable to allocate memory");
- exit(0);
- }
-
- sigemptyset(&jvmsigs);
-}
-
static void signal_lock() {
- mutex_lock(&mutex);
+ pthread_mutex_lock(&mutex);
/* When the jvm is installing its set of signal handlers, threads
- * other than the jvm thread should wait */
+ * other than the jvm thread should wait. */
if (jvm_signal_installing) {
- if (tid != thr_self()) {
- cond_wait(&cond, &mutex);
+ if (tid != pthread_self()) {
+ pthread_cond_wait(&cond, &mutex);
}
}
}
static void signal_unlock() {
- mutex_unlock(&mutex);
+ pthread_mutex_unlock(&mutex);
}
static sa_handler_t call_os_signal(int sig, sa_handler_t disp,
bool is_sigset) {
+ sa_handler_t res;
+
if (os_signal == NULL) {
if (!is_sigset) {
- os_signal = (signal_t)dlsym(RTLD_NEXT, "signal");
+ os_signal = (signal_function_t)dlsym(RTLD_NEXT, "signal");
} else {
- os_signal = (signal_t)dlsym(RTLD_NEXT, "sigset");
+ os_signal = (signal_function_t)dlsym(RTLD_NEXT, "sigset");
}
if (os_signal == NULL) {
printf("%s\n", dlerror());
exit(0);
}
}
- return (*os_signal)(sig, disp);
+
+#ifdef MACOSX
+ /* On macosx, the OS implementation of signal calls sigaction.
+ * Make sure we do not deadlock with ourself. (See JDK-8072147). */
+ reentry = true;
+#endif
+
+ res = (*os_signal)(sig, disp);
+
+#ifdef MACOSX
+ reentry = false;
+#endif
+
+ return res;
}
static void save_signal_handler(int sig, sa_handler_t disp, bool is_sigset) {
sigset_t set;
- if (sact == NULL) {
- allocate_sact();
- }
sact[sig].sa_handler = disp;
sigemptyset(&set);
sact[sig].sa_mask = set;
if (!is_sigset) {
+#ifdef SOLARIS
sact[sig].sa_flags = SA_NODEFER;
if (sig != SIGILL && sig != SIGTRAP && sig != SIGPWR) {
sact[sig].sa_flags |= SA_RESETHAND;
}
+#else
+ sact[sig].sa_flags = 0;
+#endif
} else {
sact[sig].sa_flags = 0;
}
}
static sa_handler_t set_signal(int sig, sa_handler_t disp, bool is_sigset) {
sa_handler_t oldhandler;
+ bool sigused;
bool sigblocked;
signal_lock();
- if (sact == NULL) {
- allocate_sact();
- }
- if (jvm_signal_installed && sigismember(&jvmsigs, sig)) {
+ sigused = sigismember(&jvmsigs, sig);
+ if (jvm_signal_installed && sigused) {
/* jvm has installed its signal handler for this signal. */
/* Save the handler. Don't really install it. */
if (is_sigset) {
- /* We won't honor the SIG_HOLD request to change the signal mask */
sigblocked = sigismember(&(sact[sig].sa_mask), sig);
}
oldhandler = sact[sig].sa_handler;
save_signal_handler(sig, disp, is_sigset);
+#ifdef SOLARIS
if (is_sigset && sigblocked) {
+ /* We won't honor the SIG_HOLD request to change the signal mask */
oldhandler = SIG_HOLD;
}
+#endif
signal_unlock();
return oldhandler;
} else if (jvm_signal_installing) {
/* jvm is installing its signal handlers. Install the new
@@ -179,11 +182,16 @@
sa_handler_t signal(int sig, sa_handler_t disp) {
return set_signal(sig, disp, false);
}
sa_handler_t sigset(int sig, sa_handler_t disp) {
+#ifdef _ALLBSD_SOURCE
+ printf("sigset() is not supported by BSD");
+ exit(0);
+#else
return set_signal(sig, disp, true);
+#endif
}
static int call_os_sigaction(int sig, const struct sigaction *act,
struct sigaction *oact) {
if (os_sigaction == NULL) {
@@ -196,18 +204,23 @@
return (*os_sigaction)(sig, act, oact);
}
int sigaction(int sig, const struct sigaction *act, struct sigaction *oact) {
int res;
+ bool sigused;
struct sigaction oldAct;
+#ifdef MACOSX
+ if (reentry) {
+ return call_os_sigaction(sig, act, oact);
+ }
+#endif
+
signal_lock();
- if (sact == NULL ) {
- allocate_sact();
- }
- if (jvm_signal_installed && sigismember(&jvmsigs, sig)) {
+ sigused = sigismember(&jvmsigs, sig);
+ if (jvm_signal_installed && sigused) {
/* jvm has installed its signal handler for this signal. */
/* Save the handler. Don't really install it. */
if (oact != NULL) {
*oact = sact[sig];
}
@@ -224,11 +237,11 @@
sact[sig] = oldAct;
if (oact != NULL) {
*oact = oldAct;
}
- /* Record the signals used by jvm */
+ /* Record the signals used by jvm. */
sigaddset(&jvmsigs, sig);
signal_unlock();
return res;
} else {
@@ -239,35 +252,29 @@
signal_unlock();
return res;
}
}
-/* The four functions for the jvm to call into */
+/* The three functions for the jvm to call into. */
void JVM_begin_signal_setting() {
signal_lock();
+ sigemptyset(&jvmsigs);
jvm_signal_installing = true;
- tid = thr_self();
+ tid = pthread_self();
signal_unlock();
}
void JVM_end_signal_setting() {
signal_lock();
jvm_signal_installed = true;
jvm_signal_installing = false;
- cond_broadcast(&cond);
+ pthread_cond_broadcast(&cond);
signal_unlock();
}
struct sigaction *JVM_get_signal_action(int sig) {
- if (sact == NULL) {
- allocate_sact();
- }
/* Does race condition make sense here? */
if (sigismember(&jvmsigs, sig)) {
return &sact[sig];
}
return NULL;
}
-
-int JVM_get_libjsig_version() {
- return JSIG_VERSION_1_4_1;
-}
< prev index next >