| /* Copyright (C) 2002-2014 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); |
| } |
| } |