chromium/third_party/abseil-cpp/absl/synchronization/internal/waiter_base.h

// Copyright 2023 The Abseil 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.
//

#ifndef ABSL_SYNCHRONIZATION_INTERNAL_WAITER_BASE_H_
#define ABSL_SYNCHRONIZATION_INTERNAL_WAITER_BASE_H_

#include "absl/base/config.h"
#include "absl/base/internal/thread_identity.h"
#include "absl/synchronization/internal/kernel_timeout.h"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace synchronization_internal {

// `Waiter` is a platform specific semaphore implementation that `PerThreadSem`
// waits on to implement blocking in `absl::Mutex`.  Implementations should
// inherit from `WaiterCrtp` and must implement `Wait()`, `Post()`, and `Poke()`
// as described in `WaiterBase`.  `waiter.h` selects the implementation and uses
// static-dispatch for performance.
class WaiterBase {};

template <typename T>
class WaiterCrtp : public WaiterBase {};

}  // namespace synchronization_internal
ABSL_NAMESPACE_END
}  // namespace absl

#endif  // ABSL_SYNCHRONIZATION_INTERNAL_WAITER_BASE_H_