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/* Copyright (C) 2002-2021 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
<https://www.gnu.org/licenses/>. */
#include <setjmp.h>
#include <stdlib.h>
#include "pthreadP.h"
#include <futex-internal.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. These functions must be
AS-safe, with the exception of the actual cancellation, because they
are called by wrappers around AS-safe functions like write().*/
int
__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 (__glibc_likely (curval == oldval))
{
if (self->cancelstate == PTHREAD_CANCEL_ENABLE
&& CANCEL_CANCELED_AND_ASYNCHRONOUS (newval))
{
THREAD_SETMEM (self, result, PTHREAD_CANCELED);
__do_cancel ();
}
break;
}
/* Prepare the next round. */
oldval = curval;
}
return oldval;
}
libc_hidden_def (__pthread_enable_asynccancel)
/* See the comment for __pthread_enable_asynccancel regarding
the AS-safety of this function. */
void
__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 (__glibc_likely (curval == oldval))
break;
/* Prepare the next round. */
oldval = curval;
}
}
libc_hidden_def (__pthread_disable_asynccancel)
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