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			100 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			100 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (C) 2002, 2003, 2009 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 <setjmp.h>
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| #include <stdlib.h>
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| #include "pthreadP.h"
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| 
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| 
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| /* The next two functions are similar to pthread_setcanceltype() but
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|    more specialized for the use in the cancelable functions like write().
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|    They do not need to check parameters etc.  */
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| int
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| attribute_hidden
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| __pthread_enable_asynccancel (void)
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| {
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|   struct pthread *self = THREAD_SELF;
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|   int oldval = THREAD_GETMEM (self, cancelhandling);
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| 
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|   while (1)
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|     {
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|       int newval = oldval | CANCELTYPE_BITMASK;
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| 
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|       if (newval == oldval)
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| 	break;
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| 
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|       int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
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| 					      oldval);
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|       if (__builtin_expect (curval == oldval, 1))
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| 	{
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| 	  if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
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| 	    {
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| 	      THREAD_SETMEM (self, result, PTHREAD_CANCELED);
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| 	      __do_cancel ();
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| 	    }
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| 
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| 	  break;
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| 	}
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| 
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|       /* Prepare the next round.  */
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|       oldval = curval;
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|     }
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| 
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|   return oldval;
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| }
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| 
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| 
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| void
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| internal_function attribute_hidden
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| __pthread_disable_asynccancel (int oldtype)
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| {
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|   /* If asynchronous cancellation was enabled before we do not have
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|      anything to do.  */
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|   if (oldtype & CANCELTYPE_BITMASK)
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|     return;
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| 
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|   struct pthread *self = THREAD_SELF;
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|   int newval;
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| 
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|   int oldval = THREAD_GETMEM (self, cancelhandling);
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| 
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|   while (1)
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|     {
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|       newval = oldval & ~CANCELTYPE_BITMASK;
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| 
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|       int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
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| 					      oldval);
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|       if (__builtin_expect (curval == oldval, 1))
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| 	break;
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| 
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|       /* Prepare the next round.  */
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|       oldval = curval;
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|     }
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| 
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|   /* We cannot return when we are being canceled.  Upon return the
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|      thread might be things which would have to be undone.  The
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|      following loop should loop until the cancellation signal is
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|      delivered.  */
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|   while (__builtin_expect ((newval & (CANCELING_BITMASK | CANCELED_BITMASK))
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| 			   == CANCELING_BITMASK, 0))
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|     {
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|       lll_futex_wait (&self->cancelhandling, newval, LLL_PRIVATE);
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|       newval = THREAD_GETMEM (self, cancelhandling);
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|     }
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| }
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