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- /* 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, see
- <http://www.gnu.org/licenses/>. */
- #include <errno.h>
- #include "pthreadP.h"
- #include <atomic.h>
- int
- attribute_protected
- __pthread_setcanceltype (
- int type,
- int *oldtype)
- {
- volatile struct pthread *self;
- if (type < PTHREAD_CANCEL_DEFERRED || type > PTHREAD_CANCEL_ASYNCHRONOUS)
- return EINVAL;
- self = THREAD_SELF;
- int oldval = THREAD_GETMEM (self, cancelhandling);
- while (1)
- {
- int newval = (type == PTHREAD_CANCEL_ASYNCHRONOUS
- ? oldval | CANCELTYPE_BITMASK
- : oldval & ~CANCELTYPE_BITMASK);
- /* Store the old value. */
- if (oldtype != NULL)
- *oldtype = ((oldval & CANCELTYPE_BITMASK)
- ? PTHREAD_CANCEL_ASYNCHRONOUS : PTHREAD_CANCEL_DEFERRED);
- /* Avoid doing unnecessary work. The atomic operation can
- potentially be expensive if the memory has to be locked and
- remote cache lines have to be invalidated. */
- if (oldval == newval)
- break;
- /* Update the cancel handling word. This has to be done
- atomically since other bits could be modified as well. */
- int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
- oldval);
- if (__builtin_expect (curval == oldval, 1))
- {
- if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
- {
- THREAD_SETMEM (self, result, PTHREAD_CANCELED);
- __do_cancel ();
- }
- break;
- }
- /* Prepare for the next round. */
- oldval = curval;
- }
- return 0;
- }
- strong_alias (__pthread_setcanceltype, pthread_setcanceltype)
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