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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.
*/
/*
* Exit code.
*/
#include <threads/pthread_internal.h>
#include "pthread_mutex.h"
static pthread_thread_t *last_dead_thread;
static pthread_lock_t reaper_lock;
/*
* Just a dummy lock to satisfy the switch code.
*/
pthread_lock_t threads_exit_lock = PTHREAD_LOCK_INITIALIZER;
extern int threads_alive;
void
pthread_exit(void *status)
{
pthread_thread_t *pthread = CURPTHREAD();
assert_interrupts_enabled();
assert_preemption_enabled();
disable_preemption();
pthread_lock(&pthread->lock);
pthread_exit_locked(status);
/*
* Never returns.
*/
}
/*
* Internal version. Thread lock is locked.
*/
void
pthread_exit_locked(void *status)
{
pthread_thread_t *pthread = CURPTHREAD();
int detached;
DPRINTF("(%d): %p(%p) %p\n", THISCPU, pthread, pthread->tid, status);
if (pthread->flags & THREAD_EXITING) {
panic("pthread_exit: Recursive call: 0x%x(%p)\n",
(int) pthread, pthread->tid);
}
detached = pthread->flags & THREAD_DETACHED;
pthread->flags |= THREAD_EXITING;
pthread->exitval = (oskit_u32_t) status;
pthread_unlock(&pthread->lock);
/*
* Enable preemption and interrupts while the cleanups and
* destructors are run, in case they misbehave.
*/
enable_interrupts();
enable_preemption();
/*
* Call the cancelation handlers.
*/
pthread_call_cleanup_handlers();
/*
* Call the key destructors.
*/
pthread_call_key_destructors();
#ifdef PRI_INHERIT
/*
* If this thread is inheriting from a thread (which means a thread
* or threads is waiting on it), its probably a bad thing cause
* some resource is locked up.
*/
if (! queue_empty(&pthread->waiters))
printf("PTHREAD_EXIT: TID(%p) is exiting, but other "
"threads are waiting for it. DEADLOCK?\n",
pthread->tid);
#endif
if (--threads_alive == 0)
exit(0);
/*
* Let the idle thread clean up the thread if its detached since
* we cannot reap ourselves. Note that the detached flag was
* checked above, and then the lock released. This is okay since
* the program needs to arrange its own synchronization between
* thread creation and detach/join.
*/
disable_preemption();
if (detached) {
pthread_lock(&reaper_lock);
while (last_dead_thread) {
pthread_thread_t *dead_thread;
/*
* Clear last_dead_thread and release the reaper
* lock so that it will not be held during the
* thread destruction (memory deallocation might
* block). The idle thread checks last_dead_thread
* too, so it must be cleared before the lock is
* released.
*/
dead_thread = last_dead_thread;
last_dead_thread = NULL_THREADPTR;
pthread_unlock(&reaper_lock);
pthread_lock(&dead_thread->lock);
pthread_destroy_internal(dead_thread);
/*
* Reacquire the lock before continuing.
*/
pthread_lock(&reaper_lock);
}
last_dead_thread = pthread;
pthread_sched_reschedule(RESCHED_BLOCK, &reaper_lock);
}
else {
/*
* Not detached, but perhaps someone is waiting for it.
* Wake up the joiner thread and let it reap us.
*/
pthread_mutex_lock(&pthread->mutex);
pthread->dead = 1;
pthread_cond_signal(&pthread->cond);
pthread_mutex_unlock(&pthread->mutex);
pthread_sched_reschedule(RESCHED_BLOCK, NULL);
}
/*
* Never returns.
*/
}
/*
* Called from the idle loop each time through to look for dead threads.
*/
void
pthread_reap_threads(void)
{
pthread_thread_t *pthread;
pthread_lock(&reaper_lock);
while (last_dead_thread) {
/*
* Clear last_dead_thread and release the reaper
* lock so that it will not be held during the
* thread destruction (memory deallocation might
* block).
*/
pthread = last_dead_thread;
last_dead_thread = NULL_THREADPTR;
pthread_unlock(&reaper_lock);
pthread_lock(&pthread->lock);
assert(pthread->flags & THREAD_DETACHED);
pthread_destroy_internal(pthread);
pthread_lock(&reaper_lock);
}
pthread_unlock(&reaper_lock);
}
void
pthread_init_exit()
{
pthread_lock_init(&reaper_lock);
}
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