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// 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/assert.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 until_at_least) {
std::unique_lock lock(native_type_.mutex);
if (native_type_.condition.wait_until(
lock, until_at_least, [&] { return native_type_.count != 0; })) {
native_type_.count = 0;
return true;
}
return false;
}
} // namespace pw::sync