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/*
* Copyright (c) 1996, 1998, 1999 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* Join with another thread. Note that the POSIX spec says that it is
* undefined if multiple callers try to join with the same thread. If
* that happens, things will certainly break.
*/
#include <threads/pthread_internal.h>
int
pthread_join(pthread_t tid, void **status)
{
pthread_thread_t *joinee, *joiner;
if ((joinee = tidtothread(tid)) == NULL_THREADPTR)
return EINVAL;
joiner = CURPTHREAD();
assert_preemption_enabled();
disable_preemption();
pthread_lock(&(joinee->lock));
if (joinee->flags & THREAD_DETACHED) {
pthread_unlock(&(joinee->lock));
enable_preemption();
return EINVAL;
}
pthread_unlock(&(joinee->lock));
enable_preemption();
/*
* Use a mutex here. This avoids specialized handling in the cancel
* and signal code. It works becase the "dead" flag is independent,
* protected by a spinning mutex in the reaper code.
*/
pthread_mutex_lock(&joinee->mutex);
while (!joinee->dead) {
/*
* join must be called with cancelation DEFERRED!
*/
pthread_testcancel();
pthread_cond_wait_safe(&joinee->cond, &joinee->mutex);
}
/*
* Not allowed to detach the target thread if this thread is canceled.
*/
pthread_testcancel();
disable_preemption();
if (status)
*status = (void *) joinee->exitval;
pthread_mutex_unlock(&joinee->mutex);
pthread_destroy_internal(joinee);
enable_preemption();
return 0;
}
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