freebsd-dev/lib/libkse/thread/thr_detach.c
Daniel Eischen 1cb570c531 Change low-level locking a bit so that we can tell if
a lock is being waitied on.

Fix a races in join and cancellation.

When trying to wait on a CV and the library is not yet
threaded, make it threaded so that waiting actually works.

When trying to nanosleep() and we're not threaded, just
call the system call nanosleep instead of adding the thread
to the wait queue.

Clean up adding/removing new threads to the "all threads queue",
assigning them unique ids, and tracking how many active threads
there are.  Do it all when the thread is added to the scheduling
queue instead of making pthread_create() know how to do it.

Fix a race where a thread could be marked for signal delivery
but it could be exited before we actually add the signal to it.

Other minor cleanups and bug fixes.

Submitted by:	davidxu
Approved by:	re@ (blanket for libpthread)
2003-05-24 02:29:25 +00:00

116 lines
3.9 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 <sys/types.h>
#include <machine/atomic.h>
#include <errno.h>
#include <pthread.h>
#include "thr_private.h"
__weak_reference(_pthread_detach, pthread_detach);
int
_pthread_detach(pthread_t pthread)
{
struct pthread *curthread = _get_curthread();
struct pthread *joiner;
int rval = 0;
/* Check for invalid calling parameters: */
if (pthread == NULL || pthread->magic != THR_MAGIC)
/* Return an invalid argument error: */
rval = EINVAL;
else if ((rval = _thr_ref_add(curthread, pthread,
/*include dead*/1)) != 0) {
/* Return an error: */
}
/* Check if the thread is already detached: */
else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) {
/* Return an error: */
_thr_ref_delete(curthread, pthread);
rval = EINVAL;
} else {
/* Lock the detached thread: */
THR_SCHED_LOCK(curthread, pthread);
/* Flag the thread as detached: */
pthread->attr.flags |= PTHREAD_DETACHED;
/* Retrieve any joining thread and remove it: */
joiner = pthread->joiner;
if ((joiner != NULL) && (joiner->kseg == pthread->kseg)) {
/*
* We already own the scheduler lock for the joiner.
* Take advantage of that and make the joiner runnable.
*/
if (joiner->join_status.thread == pthread) {
/*
* Set the return value for the woken thread:
*/
joiner->join_status.error = ESRCH;
joiner->join_status.ret = NULL;
joiner->join_status.thread = NULL;
_thr_setrunnable_unlocked(joiner);
}
joiner = NULL;
}
THR_SCHED_UNLOCK(curthread, pthread);
/* See if there is a thread waiting in pthread_join(): */
if ((joiner != NULL) &&
(_thr_ref_add(curthread, joiner, 0) == 0)) {
/* Lock the joiner before fiddling with it. */
THR_SCHED_LOCK(curthread, joiner);
if (joiner->join_status.thread == pthread) {
/*
* Set the return value for the woken thread:
*/
joiner->join_status.error = ESRCH;
joiner->join_status.ret = NULL;
joiner->join_status.thread = NULL;
_thr_setrunnable_unlocked(joiner);
}
THR_SCHED_UNLOCK(curthread, joiner);
_thr_ref_delete(curthread, joiner);
}
_thr_ref_delete(curthread, pthread);
}
/* Return the completion status: */
return (rval);
}