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 | |
23 | namespace folly { |
24 | |
25 | enum class AMBFlags { |
26 | NORMAL, |
27 | EXPEDITED, |
28 | }; |
29 | |
30 | FOLLY_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 | |
38 | void asymmetricHeavyBarrier(AMBFlags flags = AMBFlags::EXPEDITED); |
39 | } // namespace folly |
40 | |