1 | /* Copyright 2019 Google LLC. All Rights Reserved. |
2 | |
3 | Licensed under the Apache License, Version 2.0 (the "License"); |
4 | you may not use this file except in compliance with the License. |
5 | You may obtain a copy of the License at |
6 | |
7 | http://www.apache.org/licenses/LICENSE-2.0 |
8 | |
9 | Unless required by applicable law or agreed to in writing, software |
10 | distributed under the License is distributed on an "AS IS" BASIS, |
11 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | See the License for the specific language governing permissions and |
13 | limitations under the License. |
14 | ==============================================================================*/ |
15 | |
16 | #include "ruy/blocking_counter.h" |
17 | |
18 | #include "ruy/check_macros.h" |
19 | #include "ruy/wait.h" |
20 | |
21 | namespace ruy { |
22 | |
23 | void BlockingCounter::Reset(int initial_count) { |
24 | int old_count_value = count_.load(std::memory_order_relaxed); |
25 | RUY_DCHECK_EQ(old_count_value, 0); |
26 | (void)old_count_value; |
27 | count_.store(initial_count, std::memory_order_release); |
28 | } |
29 | |
30 | bool BlockingCounter::DecrementCount() { |
31 | int old_count_value = count_.fetch_sub(1, std::memory_order_acq_rel); |
32 | RUY_DCHECK_GT(old_count_value, 0); |
33 | int count_value = old_count_value - 1; |
34 | bool hit_zero = (count_value == 0); |
35 | if (hit_zero) { |
36 | std::lock_guard<std::mutex> lock(count_mutex_); |
37 | count_cond_.notify_all(); |
38 | } |
39 | return hit_zero; |
40 | } |
41 | |
42 | void BlockingCounter::Wait(const Duration spin_duration) { |
43 | const auto& condition = [this]() { |
44 | return count_.load(std::memory_order_acquire) == 0; |
45 | }; |
46 | ruy::Wait(condition, spin_duration, &count_cond_, &count_mutex_); |
47 | } |
48 | |
49 | } // namespace ruy |
50 | |