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			105 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			105 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Copyright (C) 2002-2017 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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   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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   <http://www.gnu.org/licenses/>.  */
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#include <errno.h>
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#include <stdlib.h>
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#include <atomic.h>
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#include "pthreadP.h"
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static void
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cleanup (void *arg)
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{
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  *(void **) arg = NULL;
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}
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int
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pthread_timedjoin_np (pthread_t threadid, void **thread_return,
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		      const struct timespec *abstime)
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{
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  struct pthread *self;
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  struct pthread *pd = (struct pthread *) threadid;
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  int result;
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  /* Make sure the descriptor is valid.  */
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  if (INVALID_NOT_TERMINATED_TD_P (pd))
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    /* Not a valid thread handle.  */
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    return ESRCH;
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  /* Is the thread joinable?.  */
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  if (IS_DETACHED (pd))
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    /* We cannot wait for the thread.  */
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    return EINVAL;
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  self = THREAD_SELF;
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  if (pd == self || self->joinid == pd)
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    /* This is a deadlock situation.  The threads are waiting for each
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       other to finish.  Note that this is a "may" error.  To be 100%
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       sure we catch this error we would have to lock the data
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       structures but it is not necessary.  In the unlikely case that
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       two threads are really caught in this situation they will
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       deadlock.  It is the programmer's problem to figure this
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       out.  */
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    return EDEADLK;
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  /* Wait for the thread to finish.  If it is already locked something
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     is wrong.  There can only be one waiter.  */
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  if (__builtin_expect (atomic_compare_and_exchange_bool_acq (&pd->joinid,
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							      self, NULL), 0))
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    /* There is already somebody waiting for the thread.  */
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    return EINVAL;
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  /* During the wait we change to asynchronous cancellation.  If we
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     are cancelled the thread we are waiting for must be marked as
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     un-wait-ed for again.  */
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  pthread_cleanup_push (cleanup, &pd->joinid);
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  /* Switch to asynchronous cancellation.  */
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  int oldtype = CANCEL_ASYNC ();
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  /* Wait for the child.  */
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  result = lll_timedwait_tid (pd->tid, abstime);
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  /* Restore cancellation mode.  */
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  CANCEL_RESET (oldtype);
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  /* Remove the handler.  */
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  pthread_cleanup_pop (0);
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  /* We might have timed out.  */
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  if (result == 0)
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    {
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      /* Store the return value if the caller is interested.  */
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      if (thread_return != NULL)
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	*thread_return = pd->result;
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      /* Free the TCB.  */
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      __free_tcb (pd);
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    }
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  else
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    pd->joinid = NULL;
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  return result;
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}
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