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