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src/java.base/macosx/native/libjsig/jsig.c
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@@ -1,7 +1,8 @@
/*
- * Copyright (c) 2001, 2015, 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.
@@ -20,118 +21,180 @@
* 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 <signal.h>
#include <dlfcn.h>
-#include <pthread.h>
+#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
-#include <stdbool.h>
-#include <stdint.h>
-#define MASK(sig) ((uint32_t)1 << (sig-1)) // 0 is not a signal.
-#if (32 < NSIG-1)
-#error "Not all signals can be encoded in jvmsigs. Adapt its type!"
+#ifdef SOLARIS
+ #include <synch.h>
+ #include <thread.h>
+#else
+ #include <pthread.h>
+#endif
+
+#if (__STDC_VERSION__ >= 199901L)
+ #include <stdbool.h>
+#else
+ #define bool int
+ #define true 1
+ #define false 0
+#endif
+
+#ifndef NSIG
+ #define NSIG SIGRTMAX
#endif
+
static struct sigaction sact[NSIG]; /* saved signal handlers */
-static uint32_t jvmsigs = 0; /* signals used by jvm */
+static sigset_t jvmsigs; /* Signals used by jvm. */
static __thread bool reentry = false; /* prevent reentry deadlock (per-thread) */
-/* used to synchronize the installation of signal handlers */
+/* Used to synchronize the installation of signal handlers. */
+#ifdef SOLARIS
+static mutex_t mutex = DEFAULTMUTEX;
+static cond_t cond = DEFAULTCV;
+static thread_t tid = 0;
+#else
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
static pthread_t tid = 0;
+#endif
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;
static void signal_lock() {
+#ifdef SOLARIS
+ mutex_lock(&mutex);
+#else
pthread_mutex_lock(&mutex);
+#endif
/* 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) {
+#ifdef SOLARIS
+ if (tid != thr_self()) {
+ cond_wait(&cond, &mutex);
+ }
+#else
if (tid != pthread_self()) {
pthread_cond_wait(&cond, &mutex);
}
+#endif
}
}
static void signal_unlock() {
+#ifdef SOLARIS
+ mutex_unlock(&mutex);
+#else
pthread_mutex_unlock(&mutex);
+#endif
}
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");
+#ifdef AIX
+ os_signal = signal;
+#else
+ os_signal = (signal_function_t)dlsym(RTLD_NEXT, "signal");
+#endif
} else {
- os_signal = (signal_t)dlsym(RTLD_NEXT, "sigset");
+#ifdef AIX
+ os_signal = sigset;
+#else
+ os_signal = (signal_function_t)dlsym(RTLD_NEXT, "sigset");
+#endif
}
if (os_signal == NULL) {
printf("%s\n", dlerror());
exit(0);
}
}
+ /* On some OSes like macosx, the OS implementation of signal calls sigaction.
+ * Make sure we do not deadlock with ourself. (See JDK-8072147). */
reentry = true;
res = (*os_signal)(sig, disp);
reentry = false;
return res;
}
-static void save_signal_handler(int sig, sa_handler_t disp) {
+static void save_signal_handler(int sig, sa_handler_t disp, bool is_sigset) {
sigset_t set;
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();
- sigused = (MASK(sig) & jvmsigs) != 0;
+ 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) {
+ sigblocked = sigismember(&(sact[sig].sa_mask), sig);
+ }
oldhandler = sact[sig].sa_handler;
- save_signal_handler(sig, disp);
+ 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
* handlers and save the old ones. jvm uses sigaction().
* Leave the piece here just in case. */
oldhandler = call_os_signal(sig, disp, is_sigset);
- save_signal_handler(sig, oldhandler);
+ save_signal_handler(sig, oldhandler, is_sigset);
/* Record the signals used by jvm */
- jvmsigs |= MASK(sig);
+ sigaddset(&jvmsigs, sig);
signal_unlock();
return oldhandler;
} else {
/* jvm has no relation with this signal (yet). Install the
@@ -146,18 +209,26 @@
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) {
+#ifdef AIX
+ os_sigaction = sigaction;
+#else
os_sigaction = (sigaction_t)dlsym(RTLD_NEXT, "sigaction");
+#endif
if (os_sigaction == NULL) {
printf("%s\n", dlerror());
exit(0);
}
}
@@ -173,11 +244,11 @@
return call_os_sigaction(sig, act, oact);
}
signal_lock();
- sigused = (MASK(sig) & jvmsigs) != 0;
+ 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];
@@ -195,12 +266,12 @@
sact[sig] = oldAct;
if (oact != NULL) {
*oact = oldAct;
}
- /* Record the signals used by jvm */
- jvmsigs |= MASK(sig);
+ /* Record the signals used by jvm. */
+ sigaddset(&jvmsigs, sig);
signal_unlock();
return res;
} else {
/* jvm has no relation with this signal (yet). Install the
@@ -210,28 +281,37 @@
signal_unlock();
return res;
}
}
-/* The three 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;
+#ifdef SOLARIS
+ tid = thr_self();
+#else
tid = pthread_self();
+#endif
signal_unlock();
}
void JVM_end_signal_setting() {
signal_lock();
jvm_signal_installed = true;
jvm_signal_installing = false;
+#ifdef SOLARIS
+ cond_broadcast(&cond);
+#else
pthread_cond_broadcast(&cond);
+#endif
signal_unlock();
}
struct sigaction *JVM_get_signal_action(int sig) {
/* Does race condition make sense here? */
- if ((MASK(sig) & jvmsigs) != 0) {
+ if (sigismember(&jvmsigs, sig)) {
return &sact[sig];
}
return NULL;
}
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