mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-21 04:31:04 +08:00
72 lines
2.6 KiB
C
72 lines
2.6 KiB
C
/* Deallocate a thread structure.
|
|
Copyright (C) 2000-2024 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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 GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <assert.h>
|
|
#include <pthread.h>
|
|
#include <stdlib.h>
|
|
|
|
#include <pt-internal.h>
|
|
|
|
#include <atomic.h>
|
|
|
|
/* List of thread structures corresponding to free thread IDs. */
|
|
extern struct __pthread *__pthread_free_threads;
|
|
extern pthread_mutex_t __pthread_free_threads_lock;
|
|
|
|
|
|
/* Deallocate the content of the thread structure for PTHREAD. */
|
|
void
|
|
__pthread_dealloc (struct __pthread *pthread)
|
|
{
|
|
if (atomic_fetch_add_relaxed (&pthread->nr_refs, -1) != 1)
|
|
return;
|
|
|
|
/* Withdraw this thread from the thread ID lookup table. */
|
|
__pthread_setid (pthread->thread, NULL);
|
|
|
|
/* Mark the thread as terminated. We broadcast the condition
|
|
here to prevent pthread_join from waiting for this thread to
|
|
exit where it was never really started. Such a call to
|
|
pthread_join is completely bogus, but unfortunately allowed
|
|
by the standards. */
|
|
__pthread_mutex_lock (&pthread->state_lock);
|
|
if (pthread->state != PTHREAD_EXITED)
|
|
__pthread_cond_broadcast (&pthread->state_cond);
|
|
__pthread_mutex_unlock (&pthread->state_lock);
|
|
|
|
/* We do not actually deallocate the thread structure, but add it to
|
|
a list of re-usable thread structures. */
|
|
__pthread_mutex_lock (&__pthread_free_threads_lock);
|
|
__pthread_enqueue (&__pthread_free_threads, pthread);
|
|
__pthread_mutex_unlock (&__pthread_free_threads_lock);
|
|
}
|
|
|
|
/* Confirm deallocation of the thread structure for PTHREAD. */
|
|
void
|
|
__pthread_dealloc_finish (struct __pthread *pthread)
|
|
{
|
|
/* Setting PTHREAD->TERMINATED makes this TCB
|
|
available for reuse. After that point, we can no longer assume
|
|
that PTHREAD is valid.
|
|
|
|
Note that it is safe to not lock this update to PTHREAD->STATE:
|
|
the only way that it can now be accessed is in __pthread_alloc,
|
|
which reads this variable. */
|
|
pthread->terminated = TRUE;
|
|
}
|