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- /* Copyright (C) 2002, 2003, 2009 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 <setjmp.h>
- #include <stdlib.h>
- #include "pthreadP.h"
- /* 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. */
- int
- attribute_hidden
- __pthread_enable_asynccancel (void)
- {
- 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))
- {
- if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
- {
- THREAD_SETMEM (self, result, PTHREAD_CANCELED);
- __do_cancel ();
- }
- break;
- }
- /* Prepare the next round. */
- oldval = curval;
- }
- return oldval;
- }
- void
- internal_function attribute_hidden
- __pthread_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 newval;
- int oldval = THREAD_GETMEM (self, cancelhandling);
- while (1)
- {
- newval = oldval & ~CANCELTYPE_BITMASK;
- int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
- oldval);
- if (__builtin_expect (curval == oldval, 1))
- break;
- /* Prepare the next round. */
- oldval = curval;
- }
- /* We cannot return when we are being canceled. Upon return the
- thread might be things which would have to be undone. The
- following loop should loop until the cancellation signal is
- delivered. */
- while (__builtin_expect ((newval & (CANCELING_BITMASK | CANCELED_BITMASK))
- == CANCELING_BITMASK, 0))
- {
- lll_futex_wait (&self->cancelhandling, newval, LLL_PRIVATE);
- newval = THREAD_GETMEM (self, cancelhandling);
- }
- }
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