freebsd-dev/lib/libpthread/thread/thr_sigwait.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;
	struct sigwait_data waitdata;
	sigset_t	waitset;
	kse_critical_t  crit;
	siginfo_t	siginfo;

	if (!_kse_isthreaded() ||
	    (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)) {
		if (info == NULL)
			info = &siginfo;
		return (__sys_sigtimedwait((sigset_t *)set, info,
			(struct timespec *)timeout));
	}

	/*
	 * 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);

	/*
	 * 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.
	 */

	crit = _kse_critical_enter();
	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);
			siginfo = curthread->siginfo[i - 1];
			KSE_SCHED_UNLOCK(curthread->kse,
				curthread->kseg);
			_kse_critical_leave(crit);
			ret = i;
			goto OUT;
		}
	}
	curthread->timeout = 0;
	curthread->interrupted = 0;
	_thr_set_timeout(timeout);
	/* Wait for a signal: */
	siginfo.si_signo = 0;
	waitdata.waitset = &waitset;
	waitdata.siginfo = &siginfo;
	curthread->data.sigwait = &waitdata;
	THR_SET_STATE(curthread, PS_SIGWAIT);
	_thr_sched_switch_unlocked(curthread);
	/*
	 * Return the signal number to the caller:
	 */
	if (siginfo.si_signo > 0) {
		ret = siginfo.si_signo;
	} else {
		if (curthread->interrupted)
			errno = EINTR;
		else if (curthread->timeout)
			errno = EAGAIN;
		ret = -1;
	}
	curthread->timeout = 0;
	curthread->interrupted = 0;
	/*
	 * Probably unnecessary, but since it's in a union struct
	 * we don't know how it could be used in the future.
	 */
	curthread->data.sigwait = NULL;

OUT:
	if (ret > 0 && info != NULL)
		*info = siginfo;

	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);
}