mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-26 15:00:06 +00:00
09efc3ba12
2002-12-07 Ulrich Drepper <drepper@redhat.com> * sysdeps/generic/bits/stdio-lock.h (_IO_lock_trylock): New define.
63 lines
1.9 KiB
C
63 lines
1.9 KiB
C
/* Copyright (C) 2002 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 <signal.h>
|
|
#include "pthreadP.h"
|
|
#include "atomic.h"
|
|
|
|
|
|
int
|
|
pthread_cancel (th)
|
|
pthread_t th;
|
|
{
|
|
volatile struct pthread *pd = (volatile struct pthread *) th;
|
|
|
|
while (1)
|
|
{
|
|
int oldval = pd->cancelhandling;
|
|
int newval = oldval | CANCELED_BITMASK;
|
|
|
|
/* Avoid doing unnecessary work. The atomic operation can
|
|
potentially be expensive if the bug has to be locked and
|
|
remote cache lines have to be invalidated. */
|
|
if (oldval == newval)
|
|
break;
|
|
|
|
/* If the cancellation is handled asynchronously just send a
|
|
signal. We avoid this if possible since it's more
|
|
expensive. */
|
|
if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
|
|
{
|
|
/* The cancellation handler will take care of marking the
|
|
thread as canceled. */
|
|
__pthread_kill (th, SIGCANCEL);
|
|
|
|
break;
|
|
}
|
|
|
|
/* Mark the thread as canceled. This has to be done
|
|
atomically since other bits could be modified as well. */
|
|
if (atomic_compare_and_exchange_acq (&pd->cancelhandling, newval,
|
|
oldval) == 0)
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|