114 lines
2.9 KiB
C
114 lines
2.9 KiB
C
|
/* atomic.c -- Support for atomic functions if not present.
|
||
|
|
Copyright (C) 2013-2021 Free Software Foundation, Inc.
|
||
|
|
Written by Ian Lance Taylor, Google.
|
||
|
|
|
||
|
|
Redistribution and use in source and binary forms, with or without
|
||
|
|
modification, are permitted provided that the following conditions are
|
||
|
|
met:
|
||
|
|
|
||
|
|
(1) Redistributions of source code must retain the above copyright
|
||
|
|
notice, this list of conditions and the following disclaimer.
|
||
|
|
|
||
|
|
(2) Redistributions in binary form must reproduce the above copyright
|
||
|
|
notice, this list of conditions and the following disclaimer in
|
||
|
|
the documentation and/or other materials provided with the
|
||
|
|
distribution.
|
||
|
|
|
||
|
|
(3) The name of the author may not be used to
|
||
|
|
endorse or promote products derived from this software without
|
||
|
|
specific prior written permission.
|
||
|
|
|
||
|
|
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
||
|
|
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
||
|
|
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||
|
|
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
|
||
|
|
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||
|
|
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
||
|
|
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||
|
|
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
||
|
|
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
|
||
|
|
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||
|
|
POSSIBILITY OF SUCH DAMAGE. */
|
||
|
|
|
||
|
|
#include "config.h"
|
||
|
|
|
||
|
|
#include <sys/types.h>
|
||
|
|
|
||
|
|
#include "backtrace.h"
|
||
|
|
#include "backtrace-supported.h"
|
||
|
|
#include "internal.h"
|
||
|
|
|
||
|
|
/* This file holds implementations of the atomic functions that are
|
||
|
|
used if the host compiler has the sync functions but not the atomic
|
||
|
|
functions, as is true of versions of GCC before 4.7. */
|
||
|
|
|
||
|
|
#if !defined (HAVE_ATOMIC_FUNCTIONS) && defined (HAVE_SYNC_FUNCTIONS)
|
||
|
|
|
||
|
|
/* Do an atomic load of a pointer. */
|
||
|
|
|
||
|
|
void *
|
||
|
|
backtrace_atomic_load_pointer (void *arg)
|
||
|
|
{
|
||
|
|
void **pp;
|
||
|
|
void *p;
|
||
|
|
|
||
|
|
pp = (void **) arg;
|
||
|
|
p = *pp;
|
||
|
|
while (!__sync_bool_compare_and_swap (pp, p, p))
|
||
|
|
p = *pp;
|
||
|
|
return p;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Do an atomic load of an int. */
|
||
|
|
|
||
|
|
int
|
||
|
|
backtrace_atomic_load_int (int *p)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
i = *p;
|
||
|
|
while (!__sync_bool_compare_and_swap (p, i, i))
|
||
|
|
i = *p;
|
||
|
|
return i;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Do an atomic store of a pointer. */
|
||
|
|
|
||
|
|
void
|
||
|
|
backtrace_atomic_store_pointer (void *arg, void *p)
|
||
|
|
{
|
||
|
|
void **pp;
|
||
|
|
void *old;
|
||
|
|
|
||
|
|
pp = (void **) arg;
|
||
|
|
old = *pp;
|
||
|
|
while (!__sync_bool_compare_and_swap (pp, old, p))
|
||
|
|
old = *pp;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Do an atomic store of a size_t value. */
|
||
|
|
|
||
|
|
void
|
||
|
|
backtrace_atomic_store_size_t (size_t *p, size_t v)
|
||
|
|
{
|
||
|
|
size_t old;
|
||
|
|
|
||
|
|
old = *p;
|
||
|
|
while (!__sync_bool_compare_and_swap (p, old, v))
|
||
|
|
old = *p;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Do an atomic store of a int value. */
|
||
|
|
|
||
|
|
void
|
||
|
|
backtrace_atomic_store_int (int *p, int v)
|
||
|
|
{
|
||
|
|
size_t old;
|
||
|
|
|
||
|
|
old = *p;
|
||
|
|
while (!__sync_bool_compare_and_swap (p, old, v))
|
||
|
|
old = *p;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif
|