/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.   This file is part of the GNU C Library.   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.   The GNU C Library is free software; you can redistribute it and/or   modify it under the terms of the GNU Lesser General Public   License as published by the Free Software Foundation; either   version 2.1 of the License, or (at your option) any later version.   The GNU C Library is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU   Lesser General Public License for more details.   You should have received a copy of the GNU Lesser General Public   License along with the GNU C Library; if not, write to the Free   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA   02111-1307 USA.  */#include <setjmp.h>#include <signal.h>#include <stdlib.h>#include "pthreadP.h"#include "atomic.h"#ifdef IS_IN_librt/* The next two functions are similar to pthread_setcanceltype() but   more specialized for the use in the cancelable functions like write().   They do not need to check parameters etc.  */intattribute_hidden__librt_enable_asynccancel (void){  struct pthread *self = THREAD_SELF;  int oldval = THREAD_GETMEM (self, cancelhandling);  while (1)    {      int newval = oldval | CANCELTYPE_BITMASK;      if (__builtin_expect ((oldval & CANCELED_BITMASK) != 0, 0))	{	  /* If we are already exiting or if PTHREAD_CANCEL_DISABLED,	     stop right here.  */	  if ((oldval & (EXITING_BITMASK | CANCELSTATE_BITMASK)) != 0)	    break;	  int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,						  newval, oldval);	  if (__builtin_expect (curval != oldval, 0))	    {	      /* Somebody else modified the word, try again.  */	      oldval = curval;	      continue;	    }	  THREAD_SETMEM (self, result, PTHREAD_CANCELED);	  __do_cancel ();	  /* NOTREACHED */	}      int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,					      oldval);      if (__builtin_expect (curval == oldval, 1))	break;      /* Prepare the next round.  */      oldval = curval;    }  return oldval;}voidinternal_function attribute_hidden__librt_disable_asynccancel (int oldtype){  /* If asynchronous cancellation was enabled before we do not have     anything to do.  */  if (oldtype & CANCELTYPE_BITMASK)    return;  struct pthread *self = THREAD_SELF;  int oldval = THREAD_GETMEM (self, cancelhandling);  while (1)    {      int newval = oldval & ~CANCELTYPE_BITMASK;      if (newval == oldval)	break;      int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,					      oldval);      if (__builtin_expect (curval == oldval, 1))	break;      /* Prepare the next round.  */      oldval = curval;    }}#endif