| /* Copyright 2019 Google LLC. All Rights Reserved. |
| |
| Licensed under the Apache License, Version 2.0 (the "License"); |
| you may not use this file except in compliance with the License. |
| You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| ==============================================================================*/ |
| |
| #include "ruy/wait.h" |
| |
| #include <chrono> // NOLINT(build/c++11) |
| |
| namespace ruy { |
| |
| void Wait(const std::function<bool()>& condition, const Duration& spin_duration, |
| std::condition_variable* condvar, std::mutex* mutex) { |
| // First, trivial case where the `condition` is already true; |
| if (condition()) { |
| return; |
| } |
| |
| // Then, if spin_duration is nonzero, try busy-waiting. |
| if (spin_duration.count() > 0) { |
| const TimePoint wait_start = Now(); |
| while (Now() - wait_start < spin_duration) { |
| if (condition()) { |
| return; |
| } |
| } |
| } |
| |
| // Finally, do real passive waiting. |
| std::unique_lock<std::mutex> lock(*mutex); |
| condvar->wait(lock, condition); |
| } |
| |
| } // namespace ruy |