glibc/nptl/cleanup_defer.c

92 lines
2.8 KiB
C

/* Copyright (C) 2002-2018 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
<http://www.gnu.org/licenses/>. */
#include <stdlib.h>
#include "pthreadP.h"
void
__cleanup_fct_attribute
__pthread_register_cancel_defer (__pthread_unwind_buf_t *buf)
{
struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf;
struct pthread *self = THREAD_SELF;
/* Store old info. */
ibuf->priv.data.prev = THREAD_GETMEM (self, cleanup_jmp_buf);
ibuf->priv.data.cleanup = THREAD_GETMEM (self, cleanup);
int cancelhandling = THREAD_GETMEM (self, cancelhandling);
/* Disable asynchronous cancellation for now. */
if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK))
while (1)
{
int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
cancelhandling
& ~CANCELTYPE_BITMASK,
cancelhandling);
if (__glibc_likely (curval == cancelhandling))
/* Successfully replaced the value. */
break;
/* Prepare for the next round. */
cancelhandling = curval;
}
ibuf->priv.data.canceltype = (cancelhandling & CANCELTYPE_BITMASK
? PTHREAD_CANCEL_ASYNCHRONOUS
: PTHREAD_CANCEL_DEFERRED);
/* Store the new cleanup handler info. */
THREAD_SETMEM (self, cleanup_jmp_buf, (struct pthread_unwind_buf *) buf);
}
void
__cleanup_fct_attribute
__pthread_unregister_cancel_restore (__pthread_unwind_buf_t *buf)
{
struct pthread *self = THREAD_SELF;
struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf;
THREAD_SETMEM (self, cleanup_jmp_buf, ibuf->priv.data.prev);
int cancelhandling;
if (ibuf->priv.data.canceltype != PTHREAD_CANCEL_DEFERRED
&& ((cancelhandling = THREAD_GETMEM (self, cancelhandling))
& CANCELTYPE_BITMASK) == 0)
{
while (1)
{
int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
cancelhandling
| CANCELTYPE_BITMASK,
cancelhandling);
if (__glibc_likely (curval == cancelhandling))
/* Successfully replaced the value. */
break;
/* Prepare for the next round. */
cancelhandling = curval;
}
CANCELLATION_P (self);
}
}