freebsd-dev/lib/libkse/thread/thr_wait4.c
Daniel Eischen 3dc268f4e7 Fixes for signal handling:
o Don't call signal handlers with the signal handler access lock
    held.
  o Remove pending signals before calling signal handlers.  If
    pending signals were not removed prior to handling them,
    invocation of the handler could cause the handler to be
    called more than once for the same signal.  Found by: JB
  o When SIGCHLD arrives, wake up all threads in PS_WAIT_WAIT
    (wait4).

PR:		bin/15328
Reviewed by:	jasone
1999-12-17 00:56:36 +00:00

70 lines
2.6 KiB
C

/*
* Copyright (c) 1995-1998 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 <errno.h>
#include <sys/wait.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
pid_t
wait4(pid_t pid, int *istat, int options, struct rusage * rusage)
{
pid_t ret;
_thread_enter_cancellation_point();
_thread_kern_sig_defer();
/* Perform a non-blocking wait4 syscall: */
while ((ret = _thread_sys_wait4(pid, istat, options | WNOHANG, rusage)) == 0 && (options & WNOHANG) == 0) {
/* Reset the interrupted operation flag: */
_thread_run->interrupted = 0;
/* Schedule the next thread while this one waits: */
_thread_kern_sched_state(PS_WAIT_WAIT, __FILE__, __LINE__);
/* Check if this call was interrupted by a signal: */
if (_thread_run->interrupted) {
errno = EINTR;
ret = -1;
break;
}
}
_thread_kern_sig_undefer();
_thread_leave_cancellation_point();
return (ret);
}
#endif