freebsd-nq/lib/libpthread/thread/thr_join.c
Daniel Eischen a0240e2cb0 Revamp libpthread so that it has a chance of working in an SMP
environment.  This includes support for multiple KSEs and KSEGs.

The ability to create more than 1 KSE via pthread_setconcurrency()
is in the works as well as support for PTHREAD_SCOPE_SYSTEM threads.
Those should come shortly.

There are still some known issues which davidxu and I are working
on, but it'll make it easier for us by committing what we have.

This library now passes all of the ACE tests that libc_r passes
with the exception of one.  It also seems to work OK with KDE
including konqueror, kwrite, etc.  I haven't been able to get
mozilla to run due to lack of java plugin, so I'd be interested
to see how it works with that.

Reviewed by:	davidxu
2003-04-18 05:04:16 +00:00

133 lines
4.5 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 "thr_private.h"
__weak_reference(_pthread_join, pthread_join);
int
_pthread_join(pthread_t pthread, void **thread_return)
{
struct pthread *curthread = _get_curthread();
int ret = 0;
_thr_enter_cancellation_point(curthread);
/* Check if the caller has specified an invalid thread: */
if (pthread == NULL || pthread->magic != THR_MAGIC) {
/* Invalid thread: */
_thr_leave_cancellation_point(curthread);
return (EINVAL);
}
/* Check if the caller has specified itself: */
if (pthread == curthread) {
/* Avoid a deadlock condition: */
_thr_leave_cancellation_point(curthread);
return (EDEADLK);
}
/*
* Find the thread in the list of active threads or in the
* list of dead threads:
*/
if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/1)) != 0) {
/* Return an error: */
_thr_leave_cancellation_point(curthread);
return (ESRCH);
}
/* Check if this thread has been detached: */
if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) {
/* Remove the reference and return an error: */
_thr_ref_delete(curthread, pthread);
ret = ESRCH;
} else {
/* Lock the target thread while checking its state. */
THR_SCHED_LOCK(curthread, pthread);
if ((pthread->state == PS_DEAD) ||
((pthread->flags & THR_FLAGS_EXITING) != 0)) {
if (thread_return != NULL)
/* Return the thread's return value: */
*thread_return = pthread->ret;
/* Unlock the thread and remove the reference. */
THR_SCHED_UNLOCK(curthread, pthread);
_thr_ref_delete(curthread, pthread);
}
else if (pthread->joiner != NULL) {
/* Unlock the thread and remove the reference. */
THR_SCHED_UNLOCK(curthread, pthread);
_thr_ref_delete(curthread, pthread);
/* Multiple joiners are not supported. */
ret = ENOTSUP;
}
else {
/* Set the running thread to be the joiner: */
pthread->joiner = curthread;
/* Keep track of which thread we're joining to: */
curthread->join_status.thread = pthread;
/* Unlock the thread and remove the reference. */
THR_SCHED_UNLOCK(curthread, pthread);
_thr_ref_delete(curthread, pthread);
THR_SCHED_LOCK(curthread, curthread);
if (curthread->join_status.thread == pthread)
THR_SET_STATE(curthread, PS_JOIN);
THR_SCHED_UNLOCK(curthread, curthread);
while (curthread->join_status.thread == pthread) {
/* Schedule the next thread: */
_thr_sched_switch(curthread);
}
/*
* The thread return value and error are set by the
* thread we're joining to when it exits or detaches:
*/
ret = curthread->join_status.error;
if ((ret == 0) && (thread_return != NULL))
*thread_return = curthread->join_status.ret;
}
}
_thr_leave_cancellation_point(curthread);
/* Return the completion status: */
return (ret);
}