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-rw-r--r--threadproc/unix/signals.c481
1 files changed, 481 insertions, 0 deletions
diff --git a/threadproc/unix/signals.c b/threadproc/unix/signals.c
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+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define INCL_DOSEXCEPTIONS /* for OS2 */
+#include "apr_arch_threadproc.h"
+#include "apr_private.h"
+#include "apr_pools.h"
+#include "apr_signal.h"
+#include "apr_strings.h"
+
+#include <assert.h>
+#if APR_HAS_THREADS && APR_HAVE_PTHREAD_H
+#include <pthread.h>
+#endif
+
+#ifdef SIGWAIT_TAKES_ONE_ARG
+#define apr_sigwait(a,b) ((*(b)=sigwait((a)))<0?-1:0)
+#else
+#define apr_sigwait(a,b) sigwait((a),(b))
+#endif
+
+APR_DECLARE(apr_status_t) apr_proc_kill(apr_proc_t *proc, int signum)
+{
+#ifdef OS2
+ /* SIGTERM's don't work too well in OS/2 (only affects other EMX
+ * programs). CGIs may not be, esp. REXX scripts, so use a native
+ * call instead
+ */
+ if (signum == SIGTERM) {
+ return APR_OS2_STATUS(DosSendSignalException(proc->pid,
+ XCPT_SIGNAL_BREAK));
+ }
+#endif /* OS2 */
+
+ if (kill(proc->pid, signum) == -1) {
+ return errno;
+ }
+
+ return APR_SUCCESS;
+}
+
+
+#if APR_HAVE_SIGACTION
+
+#if defined(__NetBSD__) || defined(DARWIN)
+static void avoid_zombies(int signo)
+{
+ int exit_status;
+
+ while (waitpid(-1, &exit_status, WNOHANG) > 0) {
+ /* do nothing */
+ }
+}
+#endif /* DARWIN */
+
+/*
+ * Replace standard signal() with the more reliable sigaction equivalent
+ * from W. Richard Stevens' "Advanced Programming in the UNIX Environment"
+ * (the version that does not automatically restart system calls).
+ */
+APR_DECLARE(apr_sigfunc_t *) apr_signal(int signo, apr_sigfunc_t * func)
+{
+ struct sigaction act, oact;
+
+ act.sa_handler = func;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = 0;
+#ifdef SA_INTERRUPT /* SunOS */
+ act.sa_flags |= SA_INTERRUPT;
+#endif
+#if defined(__osf__) && defined(__alpha)
+ /* XXX jeff thinks this should be enabled whenever SA_NOCLDWAIT is defined */
+
+ /* this is required on Tru64 to cause child processes to
+ * disappear gracefully - XPG4 compatible
+ */
+ if ((signo == SIGCHLD) && (func == SIG_IGN)) {
+ act.sa_flags |= SA_NOCLDWAIT;
+ }
+#endif
+#if defined(__NetBSD__) || defined(DARWIN)
+ /* ignoring SIGCHLD or leaving the default disposition doesn't avoid zombies,
+ * and there is no SA_NOCLDWAIT flag, so catch the signal and reap status in
+ * the handler to avoid zombies
+ */
+ if ((signo == SIGCHLD) && (func == SIG_IGN)) {
+ act.sa_handler = avoid_zombies;
+ }
+#endif
+ if (sigaction(signo, &act, &oact) < 0)
+ return SIG_ERR;
+ return oact.sa_handler;
+}
+
+#endif /* HAVE_SIGACTION */
+
+/* AC_DECL_SYS_SIGLIST defines either of these symbols depending
+ * on the version of autoconf used. */
+#if defined(SYS_SIGLIST_DECLARED) || HAVE_DECL_SYS_SIGLIST
+
+void apr_signal_init(apr_pool_t *pglobal)
+{
+}
+const char *apr_signal_description_get(int signum)
+{
+ return (signum >= 0) ? sys_siglist[signum] : "unknown signal (number)";
+}
+
+#else /* !(SYS_SIGLIST_DECLARED || HAVE_DECL_SYS_SIGLIST) */
+
+/* we need to roll our own signal description stuff */
+
+#if defined(NSIG)
+#define APR_NUMSIG NSIG
+#elif defined(_NSIG)
+#define APR_NUMSIG _NSIG
+#elif defined(__NSIG)
+#define APR_NUMSIG __NSIG
+#else
+#define APR_NUMSIG 33 /* breaks on OS/390 with < 33; 32 is o.k. for most */
+#endif
+
+static const char *signal_description[APR_NUMSIG];
+
+#define store_desc(index, string) \
+ do { \
+ if (index >= APR_NUMSIG) { \
+ assert(index < APR_NUMSIG); \
+ } \
+ else { \
+ signal_description[index] = string; \
+ } \
+ } while (0)
+
+void apr_signal_init(apr_pool_t *pglobal)
+{
+ int sig;
+
+ store_desc(0, "Signal 0");
+
+#ifdef SIGHUP
+ store_desc(SIGHUP, "Hangup");
+#endif
+#ifdef SIGINT
+ store_desc(SIGINT, "Interrupt");
+#endif
+#ifdef SIGQUIT
+ store_desc(SIGQUIT, "Quit");
+#endif
+#ifdef SIGILL
+ store_desc(SIGILL, "Illegal instruction");
+#endif
+#ifdef SIGTRAP
+ store_desc(SIGTRAP, "Trace/BPT trap");
+#endif
+#ifdef SIGIOT
+ store_desc(SIGIOT, "IOT instruction");
+#endif
+#ifdef SIGABRT
+ store_desc(SIGABRT, "Abort");
+#endif
+#ifdef SIGEMT
+ store_desc(SIGEMT, "Emulator trap");
+#endif
+#ifdef SIGFPE
+ store_desc(SIGFPE, "Arithmetic exception");
+#endif
+#ifdef SIGKILL
+ store_desc(SIGKILL, "Killed");
+#endif
+#ifdef SIGBUS
+ store_desc(SIGBUS, "Bus error");
+#endif
+#ifdef SIGSEGV
+ store_desc(SIGSEGV, "Segmentation fault");
+#endif
+#ifdef SIGSYS
+ store_desc(SIGSYS, "Bad system call");
+#endif
+#ifdef SIGPIPE
+ store_desc(SIGPIPE, "Broken pipe");
+#endif
+#ifdef SIGALRM
+ store_desc(SIGALRM, "Alarm clock");
+#endif
+#ifdef SIGTERM
+ store_desc(SIGTERM, "Terminated");
+#endif
+#ifdef SIGUSR1
+ store_desc(SIGUSR1, "User defined signal 1");
+#endif
+#ifdef SIGUSR2
+ store_desc(SIGUSR2, "User defined signal 2");
+#endif
+#ifdef SIGCLD
+ store_desc(SIGCLD, "Child status change");
+#endif
+#ifdef SIGCHLD
+ store_desc(SIGCHLD, "Child status change");
+#endif
+#ifdef SIGPWR
+ store_desc(SIGPWR, "Power-fail restart");
+#endif
+#ifdef SIGWINCH
+ store_desc(SIGWINCH, "Window changed");
+#endif
+#ifdef SIGURG
+ store_desc(SIGURG, "urgent socket condition");
+#endif
+#ifdef SIGPOLL
+ store_desc(SIGPOLL, "Pollable event occurred");
+#endif
+#ifdef SIGIO
+ store_desc(SIGIO, "socket I/O possible");
+#endif
+#ifdef SIGSTOP
+ store_desc(SIGSTOP, "Stopped (signal)");
+#endif
+#ifdef SIGTSTP
+ store_desc(SIGTSTP, "Stopped");
+#endif
+#ifdef SIGCONT
+ store_desc(SIGCONT, "Continued");
+#endif
+#ifdef SIGTTIN
+ store_desc(SIGTTIN, "Stopped (tty input)");
+#endif
+#ifdef SIGTTOU
+ store_desc(SIGTTOU, "Stopped (tty output)");
+#endif
+#ifdef SIGVTALRM
+ store_desc(SIGVTALRM, "virtual timer expired");
+#endif
+#ifdef SIGPROF
+ store_desc(SIGPROF, "profiling timer expired");
+#endif
+#ifdef SIGXCPU
+ store_desc(SIGXCPU, "exceeded cpu limit");
+#endif
+#ifdef SIGXFSZ
+ store_desc(SIGXFSZ, "exceeded file size limit");
+#endif
+
+ for (sig = 0; sig < APR_NUMSIG; ++sig)
+ if (signal_description[sig] == NULL)
+ signal_description[sig] = apr_psprintf(pglobal, "signal #%d", sig);
+}
+
+const char *apr_signal_description_get(int signum)
+{
+ return
+ (signum >= 0 && signum < APR_NUMSIG)
+ ? signal_description[signum]
+ : "unknown signal (number)";
+}
+
+#endif /* SYS_SIGLIST_DECLARED || HAVE_DECL_SYS_SIGLIST */
+
+#if APR_HAS_THREADS && (HAVE_SIGSUSPEND || APR_HAVE_SIGWAIT) && !defined(OS2)
+
+static void remove_sync_sigs(sigset_t *sig_mask)
+{
+#ifdef SIGABRT
+ sigdelset(sig_mask, SIGABRT);
+#endif
+#ifdef SIGBUS
+ sigdelset(sig_mask, SIGBUS);
+#endif
+#ifdef SIGEMT
+ sigdelset(sig_mask, SIGEMT);
+#endif
+#ifdef SIGFPE
+ sigdelset(sig_mask, SIGFPE);
+#endif
+#ifdef SIGILL
+ sigdelset(sig_mask, SIGILL);
+#endif
+#ifdef SIGIOT
+ sigdelset(sig_mask, SIGIOT);
+#endif
+#ifdef SIGPIPE
+ sigdelset(sig_mask, SIGPIPE);
+#endif
+#ifdef SIGSEGV
+ sigdelset(sig_mask, SIGSEGV);
+#endif
+#ifdef SIGSYS
+ sigdelset(sig_mask, SIGSYS);
+#endif
+#ifdef SIGTRAP
+ sigdelset(sig_mask, SIGTRAP);
+#endif
+
+/* the rest of the signals removed from the mask in this function
+ * absolutely must be removed; you cannot block synchronous signals
+ * (requirement of pthreads API)
+ */
+}
+
+APR_DECLARE(apr_status_t) apr_signal_thread(int(*signal_handler)(int signum))
+{
+ sigset_t sig_mask;
+#if APR_HAVE_SIGWAIT
+ int (*sig_func)(int signum) = (int (*)(int))signal_handler;
+#endif
+
+ /* This thread will be the one responsible for handling signals */
+ sigfillset(&sig_mask);
+
+ /* On certain platforms, sigwait() returns EINVAL if any of various
+ * unblockable signals are included in the mask. This was first
+ * observed on AIX and Tru64.
+ */
+#ifdef SIGKILL
+ sigdelset(&sig_mask, SIGKILL);
+#endif
+#ifdef SIGSTOP
+ sigdelset(&sig_mask, SIGSTOP);
+#endif
+#ifdef SIGCONT
+ sigdelset(&sig_mask, SIGCONT);
+#endif
+#ifdef SIGWAITING
+ sigdelset(&sig_mask, SIGWAITING);
+#endif
+
+ /* no synchronous signals should be in the mask passed to sigwait() */
+ remove_sync_sigs(&sig_mask);
+
+ /* On AIX (4.3.3, at least), sigwait() won't wake up if the high-
+ * order bit of the second word of flags is turned on. sigdelset()
+ * returns an error when trying to turn this off, so we'll turn it
+ * off manually.
+ *
+ * Note that the private fields differ between 32-bit and 64-bit
+ * and even between _ALL_SOURCE and !_ALL_SOURCE. Except that on
+ * AIX 4.3 32-bit builds and 64-bit builds use the same definition.
+ *
+ * Applicable AIX fixes such that this is no longer needed:
+ *
+ * APAR IY23096 for AIX 51B, fix included in AIX 51C, and
+ * APAR IY24162 for 43X.
+ */
+#if defined(_AIX)
+#if defined(__64BIT__) && defined(_AIXVERSION_510)
+#ifdef _ALL_SOURCE
+ sig_mask.ss_set[3] &= 0x7FFFFFFF;
+#else /* not _ALL_SOURCE */
+ sig_mask.__ss_set[3] &= 0x7FFFFFFF;
+#endif
+#else /* not 64-bit build, or 64-bit build on 4.3 */
+#ifdef _ALL_SOURCE
+ sig_mask.hisigs &= 0x7FFFFFFF;
+#else /* not _ALL_SOURCE */
+ sig_mask.__hisigs &= 0x7FFFFFFF;
+#endif
+#endif
+#endif /* _AIX */
+
+ while (1) {
+#if APR_HAVE_SIGWAIT
+ int signal_received;
+
+ if (apr_sigwait(&sig_mask, &signal_received) != 0)
+ {
+ /* handle sigwait() error here */
+ }
+
+ if (sig_func(signal_received) == 1) {
+ return APR_SUCCESS;
+ }
+#elif HAVE_SIGSUSPEND
+ sigsuspend(&sig_mask);
+#else
+#error No apr_sigwait() and no sigsuspend()
+#endif
+ }
+}
+
+APR_DECLARE(apr_status_t) apr_setup_signal_thread(void)
+{
+ sigset_t sig_mask;
+ int rv;
+
+ /* All threads should mask out signals to be handled by
+ * the thread doing sigwait().
+ *
+ * No thread should ever block synchronous signals.
+ * See the Solaris man page for pthread_sigmask() for
+ * some information. Solaris chooses to knock out such
+ * processes when a blocked synchronous signal is
+ * delivered, skipping any registered signal handler.
+ * AIX doesn't call a signal handler either. At least
+ * one level of linux+glibc does call the handler even
+ * when the synchronous signal is blocked.
+ */
+ sigfillset(&sig_mask);
+ remove_sync_sigs(&sig_mask);
+
+#if defined(SIGPROCMASK_SETS_THREAD_MASK) || ! APR_HAS_THREADS
+ if ((rv = sigprocmask(SIG_SETMASK, &sig_mask, NULL)) != 0) {
+ rv = errno;
+ }
+#else
+ if ((rv = pthread_sigmask(SIG_SETMASK, &sig_mask, NULL)) != 0) {
+#ifdef HAVE_ZOS_PTHREADS
+ rv = errno;
+#endif
+ }
+#endif
+ return rv;
+}
+
+#endif /* APR_HAS_THREADS && ... */
+
+APR_DECLARE(apr_status_t) apr_signal_block(int signum)
+{
+#if APR_HAVE_SIGACTION
+ sigset_t sig_mask;
+ int rv;
+
+ sigemptyset(&sig_mask);
+
+ sigaddset(&sig_mask, signum);
+
+#if defined(SIGPROCMASK_SETS_THREAD_MASK) || ! APR_HAS_THREADS
+ if ((rv = sigprocmask(SIG_BLOCK, &sig_mask, NULL)) != 0) {
+ rv = errno;
+ }
+#else
+ if ((rv = pthread_sigmask(SIG_BLOCK, &sig_mask, NULL)) != 0) {
+#ifdef HAVE_ZOS_PTHREADS
+ rv = errno;
+#endif
+ }
+#endif
+ return rv;
+#else
+ return APR_ENOTIMPL;
+#endif
+}
+
+APR_DECLARE(apr_status_t) apr_signal_unblock(int signum)
+{
+#if APR_HAVE_SIGACTION
+ sigset_t sig_mask;
+ int rv;
+
+ sigemptyset(&sig_mask);
+
+ sigaddset(&sig_mask, signum);
+
+#if defined(SIGPROCMASK_SETS_THREAD_MASK) || ! APR_HAS_THREADS
+ if ((rv = sigprocmask(SIG_UNBLOCK, &sig_mask, NULL)) != 0) {
+ rv = errno;
+ }
+#else
+ if ((rv = pthread_sigmask(SIG_UNBLOCK, &sig_mask, NULL)) != 0) {
+#ifdef HAVE_ZOS_PTHREADS
+ rv = errno;
+#endif
+ }
+#endif
+ return rv;
+#else
+ return APR_ENOTIMPL;
+#endif
+}