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			78 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			78 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (C) 2003-2013 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
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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 <sysdep.h>
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| #include <lowlevellock.h>
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| #include <pthreadP.h>
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| 
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| /* Wait on barrier.  */
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| int
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| pthread_barrier_wait (barrier)
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|      pthread_barrier_t *barrier;
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| {
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|   union sparc_pthread_barrier *ibarrier
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|     = (union sparc_pthread_barrier *) barrier;
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|   int result = 0;
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|   int private = ibarrier->s.pshared ? LLL_SHARED : LLL_PRIVATE;
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| 
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|   /* Make sure we are alone.  */
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|   lll_lock (ibarrier->b.lock, private);
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| 
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|   /* One more arrival.  */
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|   --ibarrier->b.left;
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| 
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|   /* Are these all?  */
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|   if (ibarrier->b.left == 0)
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|     {
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|       /* Yes. Increment the event counter to avoid invalid wake-ups and
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| 	 tell the current waiters that it is their turn.  */
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|       ++ibarrier->b.curr_event;
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| 
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|       /* Wake up everybody.  */
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|       lll_futex_wake (&ibarrier->b.curr_event, INT_MAX, private);
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| 
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|       /* This is the thread which finished the serialization.  */
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|       result = PTHREAD_BARRIER_SERIAL_THREAD;
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|     }
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|   else
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|     {
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|       /* The number of the event we are waiting for.  The barrier's event
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| 	 number must be bumped before we continue.  */
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|       unsigned int event = ibarrier->b.curr_event;
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| 
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|       /* Before suspending, make the barrier available to others.  */
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|       lll_unlock (ibarrier->b.lock, private);
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| 
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|       /* Wait for the event counter of the barrier to change.  */
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|       do
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| 	lll_futex_wait (&ibarrier->b.curr_event, event, private);
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|       while (event == ibarrier->b.curr_event);
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|     }
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| 
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|   /* Make sure the init_count is stored locally or in a register.  */
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|   unsigned int init_count = ibarrier->b.init_count;
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| 
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|   /* If this was the last woken thread, unlock.  */
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|   if (atomic_increment_val (&ibarrier->b.left) == init_count)
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|     /* We are done.  */
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|     lll_unlock (ibarrier->b.lock, private);
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| 
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|   return result;
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| }
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