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| -rw-r--r-- | nptl/libc-cancellation.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/nptl/libc-cancellation.c b/nptl/libc-cancellation.c new file mode 100644 index 0000000000..ae568cfa78 --- /dev/null +++ b/nptl/libc-cancellation.c @@ -0,0 +1,84 @@ +/* Copyright (C) 2002 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 <stdlib.h> +#include "pthreadP.h" +#include "atomic.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 +__libc_enable_asynccancel (void) +{ + struct pthread *self = THREAD_SELF; + int oldval; + + while (1) + { + oldval = THREAD_GETMEM (self, cancelhandling); + int newval = oldval | CANCELTYPE_BITMASK; + + if (newval == oldval) + break; + + if (atomic_compare_and_exchange_acq (&self->cancelhandling, newval, + oldval) == 0) + { + if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval)) + { + THREAD_SETMEM (self, result, PTHREAD_CANCELED); + __do_cancel (); + } + + break; + } + } + + return oldval; +} + + +void +internal_function attribute_hidden +__libc_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; + + while (1) + { + int oldval = THREAD_GETMEM (self, cancelhandling); + int newval = oldval & ~CANCELTYPE_BITMASK; + + if (newval == oldval) + break; + + if (atomic_compare_and_exchange_acq (&self->cancelhandling, newval, + oldval) == 0) + break; + } +} |