| // 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. |
| |
| #include "pw_sync/binary_semaphore.h" |
| |
| #include "pw_assert/check.h" |
| |
| using pw::chrono::SystemClock; |
| |
| namespace pw::sync { |
| |
| void BinarySemaphore::release() { |
| std::lock_guard lock(native_type_.mutex); |
| PW_DCHECK_UINT_LT(native_type_.count, BinarySemaphore::max()); |
| ++native_type_.count; |
| native_type_.condition.notify_one(); |
| } |
| |
| void BinarySemaphore::acquire() { |
| std::unique_lock lock(native_type_.mutex); |
| native_type_.condition.wait(lock, [&] { return native_type_.count != 0; }); |
| native_type_.count = 0; |
| } |
| |
| bool BinarySemaphore::try_acquire() noexcept { |
| std::lock_guard lock(native_type_.mutex); |
| if (native_type_.count != 0) { |
| native_type_.count = 0; |
| return true; |
| } |
| return false; |
| } |
| |
| bool BinarySemaphore::try_acquire_until(SystemClock::time_point deadline) { |
| std::unique_lock lock(native_type_.mutex); |
| if (native_type_.condition.wait_until( |
| lock, deadline, [&] { return native_type_.count != 0; })) { |
| native_type_.count = 0; |
| return true; |
| } |
| return false; |
| } |
| |
| } // namespace pw::sync |