freebsd-dev/lib/libpthread/thread/thr_sigwait.c
David Xu 5af40bb68a Because there are only _SIG_MAXSIG elements in thread siginfo array,
use [signal number - 1] as subscript to access the array.
2003-06-30 06:16:50 +00:00

250 lines
7.0 KiB
C

//depot/projects/kse/lib/libpthread/thread/thr_sigwait.c#1 - branch change 15154 (text+ko)
/*
* Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <signal.h>
#include <sys/param.h>
#include <sys/signalvar.h>
#include <errno.h>
#include <pthread.h>
#include "thr_private.h"
__weak_reference(__sigwait, sigwait);
__weak_reference(__sigtimedwait, sigtimedwait);
__weak_reference(__sigwaitinfo, sigwaitinfo);
static int
lib_sigtimedwait(const sigset_t *set, siginfo_t *info,
const struct timespec * timeout)
{
struct pthread *curthread = _get_curthread();
int ret = 0;
int i;
sigset_t tempset, waitset;
struct sigaction act;
kse_critical_t crit;
siginfo_t siginfo;
if (!_kse_isthreaded()) {
if (info == NULL)
info = &siginfo;
return __sys_sigtimedwait((sigset_t *)set, info,
(struct timespec *)timeout);
}
/*
* Specify the thread kernel signal handler.
*/
act.sa_handler = (void (*) ()) _thr_sig_handler;
act.sa_flags = SA_RESTART | SA_SIGINFO;
/* Ensure the signal handler cannot be interrupted by other signals: */
SIGFILLSET(act.sa_mask);
/*
* Initialize the set of signals that will be waited on:
*/
waitset = *set;
/* These signals can't be waited on. */
SIGDELSET(waitset, SIGKILL);
SIGDELSET(waitset, SIGSTOP);
crit = _kse_critical_enter();
KSE_LOCK_ACQUIRE(curthread->kse, &_thread_signal_lock);
/*
* Enter a loop to find the signals that are SIG_DFL. For
* these signals we must install a dummy signal handler in
* order for the kernel to pass them in to us. POSIX says
* that the _application_ must explicitly install a dummy
* handler for signals that are SIG_IGN in order to sigwait
* on them. Note that SIG_IGN signals are left in the
* mask because a subsequent sigaction could enable an
* ignored signal.
*/
SIGEMPTYSET(tempset);
for (i = 1; i <= _SIG_MAXSIG; i++) {
if (SIGISMEMBER(waitset, i) &&
(_thread_sigact[i - 1].sa_handler == SIG_DFL)) {
_thread_dfl_count[i - 1]++;
SIGADDSET(tempset, i);
if (_thread_dfl_count[i - 1] == 1) {
if (__sys_sigaction(i, &act, NULL) != 0)
/* ret = -1 */;
}
}
}
if (ret == 0) {
/* Done accessing _thread_dfl_count for now. */
KSE_LOCK_RELEASE(curthread->kse, &_thread_signal_lock);
KSE_SCHED_LOCK(curthread->kse, curthread->kseg);
for (i = 1; i <= _SIG_MAXSIG; ++i) {
if (SIGISMEMBER(waitset, i) &&
SIGISMEMBER(curthread->sigpend, i)) {
SIGDELSET(curthread->sigpend, i);
*info = curthread->siginfo[i - 1];
KSE_SCHED_UNLOCK(curthread->kse,
curthread->kseg);
_kse_critical_leave(crit);
return (i);
}
}
curthread->timeout = 0;
_thr_set_timeout(timeout);
/* Wait for a signal: */
curthread->oldsigmask = curthread->sigmask;
siginfo.si_signo = 0;
curthread->data.sigwaitinfo = &siginfo;
SIGFILLSET(curthread->sigmask);
SIGSETNAND(curthread->sigmask, waitset);
THR_SET_STATE(curthread, PS_SIGWAIT);
_thr_sched_switch_unlocked(curthread);
/*
* Return the signal number to the caller:
* XXX Here is race, how about a signal come in before
* we reach here? so we might got an incorrect timeout
* status.
*/
if (siginfo.si_signo > 0) {
if (info)
*info = siginfo;
ret = siginfo.si_signo;
} else {
if (curthread->timeout)
errno = EAGAIN;
ret = -1;
}
/*
* Probably unnecessary, but since it's in a union struct
* we don't know how it could be used in the future.
*/
crit = _kse_critical_enter();
curthread->data.sigwaitinfo = NULL;
/*
* Relock the array of SIG_DFL wait counts.
*/
KSE_LOCK_ACQUIRE(curthread->kse, &_thread_signal_lock);
}
/* Restore the sigactions: */
act.sa_handler = SIG_DFL;
for (i = 1; i <= _SIG_MAXSIG; i++) {
if (SIGISMEMBER(tempset, i)) {
_thread_dfl_count[i - 1]--;
if ((_thread_sigact[i - 1].sa_handler == SIG_DFL) &&
(_thread_dfl_count[i - 1] == 0)) {
if (__sys_sigaction(i, &act, NULL) != 0)
/* ret = -1 */ ;
}
}
}
/* Done accessing _thread_dfl_count. */
KSE_LOCK_RELEASE(curthread->kse, &_thread_signal_lock);
_kse_critical_leave(crit);
return (ret);
}
int
__sigtimedwait(const sigset_t *set, siginfo_t *info,
const struct timespec * timeout)
{
struct pthread *curthread = _get_curthread();
int ret;
_thr_enter_cancellation_point(curthread);
ret = lib_sigtimedwait(set, info, timeout);
_thr_leave_cancellation_point(curthread);
return (ret);
}
int _sigtimedwait(const sigset_t *set, siginfo_t *info,
const struct timespec * timeout)
{
return lib_sigtimedwait(set, info, timeout);
}
int
__sigwaitinfo(const sigset_t *set, siginfo_t *info)
{
struct pthread *curthread = _get_curthread();
int ret;
_thr_enter_cancellation_point(curthread);
ret = lib_sigtimedwait(set, info, NULL);
_thr_leave_cancellation_point(curthread);
return (ret);
}
int
_sigwaitinfo(const sigset_t *set, siginfo_t *info)
{
return lib_sigtimedwait(set, info, NULL);
}
int
__sigwait(const sigset_t *set, int *sig)
{
struct pthread *curthread = _get_curthread();
int ret;
_thr_enter_cancellation_point(curthread);
ret = lib_sigtimedwait(set, NULL, NULL);
if (ret > 0) {
*sig = ret;
ret = 0;
}
else
ret = -1;
_thr_leave_cancellation_point(curthread);
return (ret);
}
int
_sigwait(const sigset_t *set, int *sig)
{
int ret;
ret = lib_sigtimedwait(set, NULL, NULL);
if (ret > 0) {
*sig = ret;
ret = 0;
} else {
ret = -1;
}
return (ret);
}