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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, 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. */
int
attribute_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 stop right here. */
if ((oldval & EXITING_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;
}
void
internal_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;
}
}
/* XXX Hack ahead. In librt we currently do not have access to a
function equivalent to __pthread_unwind. Therefore we just raise a
signal. */
void
attribute_hidden
__pthread_unwind (__pthread_unwind_buf_t *buf)
{
INTERNAL_SYSCALL_DECL (err);
while (1)
INTERNAL_SYSCALL (tkill, err, 2, THREAD_GETMEM (THREAD_SELF, tid),
SIGCANCEL);
}
#endif
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