atomic-ops.h
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1 /* Copyright (c) 2013, Ben Noordhuis <info@bnoordhuis.nl>
2  *
3  * Permission to use, copy, modify, and/or distribute this software for any
4  * purpose with or without fee is hereby granted, provided that the above
5  * copyright notice and this permission notice appear in all copies.
6  *
7  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
10  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
12  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
13  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
14  */
15 
16 #ifndef UV_ATOMIC_OPS_H_
17 #define UV_ATOMIC_OPS_H_
18 
19 #include "internal.h" /* UV_UNUSED */
20 
21 #if defined(__SUNPRO_C) || defined(__SUNPRO_CC)
22 #include <atomic.h>
23 #endif
24 
25 UV_UNUSED(static int cmpxchgi(int* ptr, int oldval, int newval));
26 UV_UNUSED(static void cpu_relax(void));
27 
28 /* Prefer hand-rolled assembly over the gcc builtins because the latter also
29  * issue full memory barriers.
30  */
31 UV_UNUSED(static int cmpxchgi(int* ptr, int oldval, int newval)) {
32 #if defined(__i386__) || defined(__x86_64__)
33  int out;
34  __asm__ __volatile__ ("lock; cmpxchg %2, %1;"
35  : "=a" (out), "+m" (*(volatile int*) ptr)
36  : "r" (newval), "0" (oldval)
37  : "memory");
38  return out;
39 #elif defined(__MVS__)
40  unsigned int op4;
41  if (__plo_CSST(ptr, (unsigned int*) &oldval, newval,
42  (unsigned int*) ptr, *ptr, &op4))
43  return oldval;
44  else
45  return op4;
46 #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
47  return atomic_cas_uint((uint_t *)ptr, (uint_t)oldval, (uint_t)newval);
48 #else
49  return __sync_val_compare_and_swap(ptr, oldval, newval);
50 #endif
51 }
52 
53 UV_UNUSED(static void cpu_relax(void)) {
54 #if defined(__i386__) || defined(__x86_64__)
55  __asm__ __volatile__ ("rep; nop"); /* a.k.a. PAUSE */
56 #elif (defined(__arm__) && __ARM_ARCH >= 7) || defined(__aarch64__)
57  __asm__ volatile("yield");
58 #endif
59 }
60 
61 #endif /* UV_ATOMIC_OPS_H_ */
ptr
char * ptr
Definition: abseil-cpp/absl/base/internal/low_level_alloc_test.cc:45
gen_build_yaml.out
dictionary out
Definition: src/benchmark/gen_build_yaml.py:24
internal.h
UV_UNUSED
UV_UNUSED(static int cmpxchgi(int *ptr, int oldval, int newval))
Definition: atomic-ops.h:31

grpc
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autogenerated on Thu Mar 13 2025 02:58:35