freebsd-src/lib/libc_r/uthread/uthread_suspend_np.c
2007-01-12 07:26:21 +00:00

102 lines
3.0 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. 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 <pthread.h>
#include "pthread_private.h"
static void suspend_common(struct pthread *thread);
__weak_reference(_pthread_suspend_np, pthread_suspend_np);
__weak_reference(_pthread_suspend_all_np, pthread_suspend_all_np);
/* Suspend a thread: */
int
_pthread_suspend_np(pthread_t thread)
{
int ret;
/* Suspending the current thread doesn't make sense. */
if (thread == _get_curthread())
ret = EDEADLK;
/* Find the thread in the list of active threads: */
else if ((ret = _find_thread(thread)) == 0) {
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
_thread_kern_sig_defer();
suspend_common(thread);
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
}
return (ret);
}
void
_pthread_suspend_all_np(void)
{
struct pthread *curthread = _get_curthread();
struct pthread *thread;
/*
* Defer signals to protect the scheduling queues from
* access by the signal handler:
*/
_thread_kern_sig_defer();
TAILQ_FOREACH(thread, &_thread_list, tle) {
if (thread != curthread)
suspend_common(thread);
}
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
}
void
suspend_common(struct pthread *thread)
{
thread->flags |= PTHREAD_FLAGS_SUSPENDED;
if (thread->flags & PTHREAD_FLAGS_IN_PRIOQ) {
PTHREAD_PRIOQ_REMOVE(thread);
PTHREAD_SET_STATE(thread, PS_SUSPENDED);
}
}