glibc/nptl/pthread_setcancelstate.c

61 lines
1.7 KiB
C

/* Copyright (C) 2002-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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 <errno.h>
#include "pthreadP.h"
#include <atomic.h>
#include <libc-lockP.h>
int
__pthread_setcancelstate (int state, int *oldstate)
{
volatile struct pthread *self;
if (state < PTHREAD_CANCEL_ENABLE || state > PTHREAD_CANCEL_DISABLE)
return EINVAL;
self = THREAD_SELF;
int oldval = atomic_load_relaxed (&self->cancelhandling);
while (1)
{
int newval = (state == PTHREAD_CANCEL_DISABLE
? oldval | CANCELSTATE_BITMASK
: oldval & ~CANCELSTATE_BITMASK);
if (oldstate != NULL)
*oldstate = ((oldval & CANCELSTATE_BITMASK)
? PTHREAD_CANCEL_DISABLE : PTHREAD_CANCEL_ENABLE);
if (oldval == newval)
break;
if (atomic_compare_exchange_weak_acquire (&self->cancelhandling,
&oldval, newval))
{
if (cancel_enabled_and_canceled_and_async (newval))
__do_cancel ();
break;
}
}
return 0;
}
libc_hidden_def (__pthread_setcancelstate)
weak_alias (__pthread_setcancelstate, pthread_setcancelstate)