freebsd-dev/lib/libc_r/uthread/uthread_resume_np.c
deischen 01750324fa Add weak definitions for wrapped system calls. In general:
_foo - wrapped system call
	foo - weak definition to _foo

and for cancellation points:

	_foo - wrapped system call
	__foo - enter cancellation point, call _foo(), leave
	        cancellation point
	foo - weak definition to __foo

Change use of global _thread_run to call a function to get the
currently running thread.

Make all pthread_foo functions weak definitions to _pthread_foo,
where _pthread_foo is the implementation.  This allows an application
to provide its own pthread functions.

Provide slightly different versions of pthread_mutex_lock and
pthread_mutex_init so that we can tell the difference between
a libc mutex and an application mutex.  Threads holding mutexes
internal to libc should never be allowed to exit, call signal
handlers, or cancel.

Approved by:	-arch
2001-01-24 13:03:38 +00:00

93 lines
3.1 KiB
C

/*
* Copyright (c) 1995 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 <pthread.h>
#include "pthread_private.h"
#pragma weak pthread_resume_np=_pthread_resume_np
/* Resume a thread: */
int
_pthread_resume_np(pthread_t thread)
{
int ret;
enum pthread_susp old_suspended;
/* Find the thread in the list of active threads: */
if ((ret = _find_thread(thread)) == 0) {
/* Cancel any pending suspensions: */
old_suspended = thread->suspended;
thread->suspended = SUSP_NO;
/* Is it currently suspended? */
if (thread->state == PS_SUSPENDED) {
/*
* Defer signals to protect the scheduling queues
* from access by the signal handler:
*/
_thread_kern_sig_defer();
switch (old_suspended) {
case SUSP_MUTEX_WAIT:
/* Set the thread's state back. */
PTHREAD_SET_STATE(thread,PS_MUTEX_WAIT);
break;
case SUSP_COND_WAIT:
/* Set the thread's state back. */
PTHREAD_SET_STATE(thread,PS_COND_WAIT);
break;
case SUSP_NOWAIT:
/* Allow the thread to run. */
PTHREAD_SET_STATE(thread,PS_RUNNING);
PTHREAD_WAITQ_REMOVE(thread);
PTHREAD_PRIOQ_INSERT_TAIL(thread);
break;
case SUSP_NO:
case SUSP_YES:
/* Allow the thread to run. */
PTHREAD_SET_STATE(thread,PS_RUNNING);
PTHREAD_PRIOQ_INSERT_TAIL(thread);
break;
}
/*
* Undefer and handle pending signals, yielding if
* necessary:
*/
_thread_kern_sig_undefer();
}
}
return(ret);
}