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			88 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			88 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (C) 2002-2012 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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| 
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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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| 
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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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| 
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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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|    <http://www.gnu.org/licenses/>.  */
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| 
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| #include <errno.h>
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| #include <shlib-compat.h>
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| #include "pthreadP.h"
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| #include <stap-probe.h>
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| 
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| 
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| int
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| __pthread_cond_destroy (cond)
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|      pthread_cond_t *cond;
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| {
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|   int pshared = (cond->__data.__mutex == (void *) ~0l)
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| 		? LLL_SHARED : LLL_PRIVATE;
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| 
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|   LIBC_PROBE (cond_destroy, 1, cond);
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| 
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|   /* Make sure we are alone.  */
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|   lll_lock (cond->__data.__lock, pshared);
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| 
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|   if (cond->__data.__total_seq > cond->__data.__wakeup_seq)
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|     {
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|       /* If there are still some waiters which have not been
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| 	 woken up, this is an application bug.  */
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|       lll_unlock (cond->__data.__lock, pshared);
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|       return EBUSY;
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|     }
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| 
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|   /* Tell pthread_cond_*wait that this condvar is being destroyed.  */
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|   cond->__data.__total_seq = -1ULL;
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| 
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|   /* If there are waiters which have been already signalled or
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|      broadcasted, but still are using the pthread_cond_t structure,
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|      pthread_cond_destroy needs to wait for them.  */
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|   unsigned int nwaiters = cond->__data.__nwaiters;
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| 
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|   if (nwaiters >= (1 << COND_NWAITERS_SHIFT))
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|     {
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|       /* Wake everybody on the associated mutex in case there are
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| 	 threads that have been requeued to it.
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| 	 Without this, pthread_cond_destroy could block potentially
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| 	 for a long time or forever, as it would depend on other
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| 	 thread's using the mutex.
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| 	 When all threads waiting on the mutex are woken up, pthread_cond_wait
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| 	 only waits for threads to acquire and release the internal
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| 	 condvar lock.  */
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|       if (cond->__data.__mutex != NULL
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| 	  && cond->__data.__mutex != (void *) ~0l)
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| 	{
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| 	  pthread_mutex_t *mut = (pthread_mutex_t *) cond->__data.__mutex;
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| 	  lll_futex_wake (&mut->__data.__lock, INT_MAX,
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| 			  PTHREAD_MUTEX_PSHARED (mut));
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| 	}
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| 
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|       do
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| 	{
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| 	  lll_unlock (cond->__data.__lock, pshared);
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| 
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| 	  lll_futex_wait (&cond->__data.__nwaiters, nwaiters, pshared);
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| 
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| 	  lll_lock (cond->__data.__lock, pshared);
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| 
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| 	  nwaiters = cond->__data.__nwaiters;
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| 	}
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|       while (nwaiters >= (1 << COND_NWAITERS_SHIFT));
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|     }
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| 
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|   return 0;
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| }
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| versioned_symbol (libpthread, __pthread_cond_destroy,
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| 		  pthread_cond_destroy, GLIBC_2_3_2);
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