mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 00:31:08 +00:00
92 lines
2.8 KiB
C
92 lines
2.8 KiB
C
/* Copyright (C) 2002-2023 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 <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 = atomic_load_relaxed (&self->cancelhandling);
|
|
|
|
while (1)
|
|
{
|
|
int newval = oldval | CANCELTYPE_BITMASK;
|
|
|
|
if (newval == oldval)
|
|
break;
|
|
|
|
if (atomic_compare_exchange_weak_acquire (&self->cancelhandling,
|
|
&oldval, newval))
|
|
{
|
|
if (cancel_enabled_and_canceled_and_async (newval))
|
|
{
|
|
self->result = PTHREAD_CANCELED;
|
|
__do_cancel ();
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
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 = atomic_load_relaxed (&self->cancelhandling);
|
|
do
|
|
{
|
|
newval = oldval & ~CANCELTYPE_BITMASK;
|
|
}
|
|
while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
|
|
&oldval, newval));
|
|
|
|
/* 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 (__glibc_unlikely ((newval & (CANCELING_BITMASK | CANCELED_BITMASK))
|
|
== CANCELING_BITMASK))
|
|
{
|
|
futex_wait_simple ((unsigned int *) &self->cancelhandling, newval,
|
|
FUTEX_PRIVATE);
|
|
newval = atomic_load_relaxed (&self->cancelhandling);
|
|
}
|
|
}
|
|
libc_hidden_def (__pthread_disable_asynccancel)
|