--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/os/aix/vm/jsig.c Fri Sep 06 20:16:09 2013 +0200
@@ -0,0 +1,233 @@
+/*
+ * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2012, 2013 SAP AG. 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.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * 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 <stdio.h>
+#include <stdlib.h>
+
+#define bool int
+#define true 1
+#define false 0
+
+// Highest so far on AIX 5.2 is SIGSAK (63)
+#define MAXSIGNUM 63
+#define MASK(sig) ((unsigned int)1 << sig)
+
+static struct sigaction sact[MAXSIGNUM]; /* saved signal handlers */
+static unsigned int jvmsigs = 0; /* signals used by jvm */
+
+/* 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 *);
+// signal_t is already defined on AIX
+typedef sa_handler_t (*signal_like_function_t)(int, sa_handler_t);
+typedef int (*sigaction_t)(int, const struct sigaction *, struct sigaction *);
+
+static signal_like_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() {
+ pthread_mutex_lock(&mutex);
+ /* When the jvm is installing its set of signal handlers, threads
+ * other than the jvm thread should wait */
+ if (jvm_signal_installing) {
+ if (tid != pthread_self()) {
+ pthread_cond_wait(&cond, &mutex);
+ }
+ }
+}
+
+static void signal_unlock() {
+ pthread_mutex_unlock(&mutex);
+}
+
+static sa_handler_t call_os_signal(int sig, sa_handler_t disp,
+ bool is_sigset) {
+ if (os_signal == NULL) {
+ if (!is_sigset) {
+ // Aix: call functions directly instead of dlsym'ing them
+ os_signal = signal;
+ } else {
+ // Aix: call functions directly instead of dlsym'ing them
+ os_signal = sigset;
+ }
+ if (os_signal == NULL) {
+ printf("%s\n", dlerror());
+ exit(0);
+ }
+ }
+ return (*os_signal)(sig, disp);
+}
+
+static void save_signal_handler(int sig, sa_handler_t disp) {
+ sigset_t set;
+ sact[sig].sa_handler = disp;
+ sigemptyset(&set);
+ sact[sig].sa_mask = set;
+ 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;
+
+ signal_lock();
+
+ sigused = (MASK(sig) & jvmsigs) != 0;
+ if (jvm_signal_installed && sigused) {
+ /* jvm has installed its signal handler for this signal. */
+ /* Save the handler. Don't really install it. */
+ oldhandler = sact[sig].sa_handler;
+ save_signal_handler(sig, disp);
+
+ 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);
+
+ /* Record the signals used by jvm */
+ jvmsigs |= MASK(sig);
+
+ signal_unlock();
+ return oldhandler;
+ } else {
+ /* jvm has no relation with this signal (yet). Install the
+ * the handler. */
+ oldhandler = call_os_signal(sig, disp, is_sigset);
+
+ signal_unlock();
+ return oldhandler;
+ }
+}
+
+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) {
+ return set_signal(sig, disp, true);
+ }
+
+static int call_os_sigaction(int sig, const struct sigaction *act,
+ struct sigaction *oact) {
+ if (os_sigaction == NULL) {
+ // Aix: call functions directly instead of dlsym'ing them
+ os_sigaction = sigaction;
+ if (os_sigaction == NULL) {
+ printf("%s\n", dlerror());
+ exit(0);
+ }
+ }
+ return (*os_sigaction)(sig, act, oact);
+}
+
+int sigaction(int sig, const struct sigaction *act, struct sigaction *oact) {
+ int res;
+ bool sigused;
+ struct sigaction oldAct;
+
+ signal_lock();
+
+ sigused = (MASK(sig) & jvmsigs) != 0;
+ 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];
+ }
+ if (act != NULL) {
+ sact[sig] = *act;
+ }
+
+ signal_unlock();
+ return 0;
+ } else if (jvm_signal_installing) {
+ /* jvm is installing its signal handlers. Install the new
+ * handlers and save the old ones. */
+ res = call_os_sigaction(sig, act, &oldAct);
+ sact[sig] = oldAct;
+ if (oact != NULL) {
+ *oact = oldAct;
+ }
+
+ /* Record the signals used by jvm */
+ jvmsigs |= MASK(sig);
+
+ signal_unlock();
+ return res;
+ } else {
+ /* jvm has no relation with this signal (yet). Install the
+ * the handler. */
+ res = call_os_sigaction(sig, act, oact);
+
+ signal_unlock();
+ return res;
+ }
+}
+
+/* The three functions for the jvm to call into */
+void JVM_begin_signal_setting() {
+ signal_lock();
+ jvm_signal_installing = true;
+ tid = pthread_self();
+ signal_unlock();
+}
+
+void JVM_end_signal_setting() {
+ signal_lock();
+ jvm_signal_installed = true;
+ jvm_signal_installing = false;
+ pthread_cond_broadcast(&cond);
+ signal_unlock();
+}
+
+struct sigaction *JVM_get_signal_action(int sig) {
+ /* Does race condition make sense here? */
+ if ((MASK(sig) & jvmsigs) != 0) {
+ return &sact[sig];
+ }
+ return NULL;
+}