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			75 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			75 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Deallocate a thread structure.
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   Copyright (C) 2000-2025 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library;  if not, see
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   <https://www.gnu.org/licenses/>.  */
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#include <assert.h>
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#include <pthread.h>
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#include <stdlib.h>
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#include <pt-internal.h>
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#include <atomic.h>
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#include <ldsodefs.h>
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/* List of thread structures corresponding to free thread IDs.  */
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extern struct __pthread *__pthread_free_threads;
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extern pthread_mutex_t __pthread_free_threads_lock;
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/* Deallocate the content of the thread structure for PTHREAD.  */
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void
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__pthread_dealloc (struct __pthread *pthread)
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{
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  if (atomic_fetch_add_relaxed (&pthread->nr_refs, -1) != 1)
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    return;
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  /* Withdraw this thread from the thread ID lookup table.  */
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  __pthread_setid (pthread->thread, NULL);
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  /* Mark the thread as terminated.  We broadcast the condition
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     here to prevent pthread_join from waiting for this thread to
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     exit where it was never really started.  Such a call to
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     pthread_join is completely bogus, but unfortunately allowed
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     by the standards.  */
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  __pthread_mutex_lock (&pthread->state_lock);
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  if (pthread->state != PTHREAD_EXITED)
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    __pthread_cond_broadcast (&pthread->state_cond);
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  __pthread_mutex_unlock (&pthread->state_lock);
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  /* We do not actually deallocate the thread structure, but add it to
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     a list of re-usable thread structures.  */
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  __pthread_mutex_lock (&__pthread_free_threads_lock);
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  __pthread_enqueue (&__pthread_free_threads, pthread);
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  __pthread_mutex_unlock (&__pthread_free_threads_lock);
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}
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libc_hidden_def (__pthread_dealloc)
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/* Confirm deallocation of the thread structure for PTHREAD.  */
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void
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__pthread_dealloc_finish (struct __pthread *pthread)
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{
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  /* Setting PTHREAD->TERMINATED makes this TCB
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     available for reuse.  After that point, we can no longer assume
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     that PTHREAD is valid.
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     Note that it is safe to not lock this update to PTHREAD->STATE:
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     the only way that it can now be accessed is in __pthread_alloc,
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     which reads this variable.  */
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  pthread->terminated = TRUE;
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}
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libc_hidden_def (__pthread_dealloc_finish)
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