/* atomic.c -- Support for atomic functions if not present.   Copyright (C) 2013-2026 Free Software Foundation, Inc.   Written by Ian Lance Taylor, Google. Redistribution and use in source and binary forms, with or withoutmodification, are permitted provided that the following conditions aremet:     (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 ORIMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIEDWARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AREDISCLAIMED. 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 ORSERVICES; 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) ARISINGIN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THEPOSSIBILITY 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.  */ intbacktrace_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.  */ voidbacktrace_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.  */ voidbacktrace_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.  */ voidbacktrace_atomic_store_int (int *p, int v){  int old;   old = *p;  while (!__sync_bool_compare_and_swap (p, old, v))    old = *p;} #endif