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DEFINITIONS
This source file includes following definitions.
- APR_DECLARE
- avoid_zombies
- APR_DECLARE
- apr_signal_init
- apr_signal_description_get
- apr_signal_init
- apr_signal_description_get
- remove_sync_sigs
- APR_DECLARE
- APR_DECLARE
- APR_DECLARE
- APR_DECLARE
/* 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)
*
* SIGUSR2 is being removed from the mask for the convenience of
* Purify users (Solaris, HP-UX, SGI) since Purify uses SIGUSR2
*/
#ifdef SIGUSR2
sigdelset(sig_mask, SIGUSR2);
#endif
}
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
}