| // Copyright 2020 The Pigweed Authors |
| // |
| // 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 |
| // |
| // https://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. |
| #pragma once |
| |
| #include "pw_chrono/system_clock.h" |
| #include "pw_sync/binary_semaphore.h" |
| |
| namespace pw::sync { |
| |
| inline BinarySemaphore::BinarySemaphore() |
| : native_type_{.mutex = {}, .condition = {}, .count = 0} {} |
| |
| inline BinarySemaphore::~BinarySemaphore() {} |
| |
| inline bool BinarySemaphore::try_acquire_for( |
| chrono::SystemClock::duration timeout) { |
| // Due to spurious condition variable wakeups we prefer not to use wait_for() |
| // as we may grossly extend the effective deadline after a spruious wakeup. |
| // Ergo we instead use the derived deadline which can be re-used many times |
| // without shifting the effective deadline. For more details on spurious |
| // wakeups and CVs on Windows and POSIX see: |
| // https://en.wikipedia.org/wiki/Spurious_wakeup |
| return try_acquire_until(chrono::SystemClock::TimePointAfterAtLeast(timeout)); |
| } |
| |
| inline BinarySemaphore::native_handle_type BinarySemaphore::native_handle() { |
| return native_type_; |
| } |
| |
| } // namespace pw::sync |
