1/*
2 * Copyright 2016-present Facebook, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#pragma once
18
19#include <atomic>
20
21#include <folly/portability/Asm.h>
22
23namespace folly {
24
25enum class AMBFlags {
26 NORMAL,
27 EXPEDITED,
28};
29
30FOLLY_ALWAYS_INLINE void asymmetricLightBarrier() {
31 if (kIsLinux) {
32 asm_volatile_memory();
33 } else {
34 std::atomic_thread_fence(std::memory_order_seq_cst);
35 }
36}
37
38void asymmetricHeavyBarrier(AMBFlags flags = AMBFlags::EXPEDITED);
39} // namespace folly
40