glibc/nptl/cancellation.c
Adhemerval Zanella 8c1c0aae20 nptl: Move cancel type out of cancelhandling
Now that the thread cancellation type is not accessed concurrently
anymore, it is possible to move it out the cancelhandling.

By removing the cancel state out of the internal thread cancel handling
state there is no need to check if cancelled bit was set in CAS
operation.

It allows simplifing the cancellation wrappers and the
CANCEL_CANCELED_AND_ASYNCHRONOUS is removed.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
2021-06-09 15:16:45 -03:00

67 lines
2.2 KiB
C

/* 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, canceltype);
THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_ASYNCHRONOUS);
int ch = THREAD_GETMEM (self, cancelhandling);
if (self->cancelstate == PTHREAD_CANCEL_ENABLE
&& (ch & CANCELED_BITMASK)
&& !(ch & EXITING_BITMASK)
&& !(ch & TERMINATED_BITMASK))
{
THREAD_SETMEM (self, result, PTHREAD_CANCELED);
__do_cancel ();
}
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 == PTHREAD_CANCEL_ASYNCHRONOUS)
return;
struct pthread *self = THREAD_SELF;
self->canceltype = PTHREAD_CANCEL_DEFERRED;
}
libc_hidden_def (__pthread_disable_asynccancel)