chromium/third_party/abseil-cpp/absl/strings/internal/cordz_update_tracker.h

// Copyright 2021 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_STRINGS_INTERNAL_CORDZ_UPDATE_TRACKER_H_
#define ABSL_STRINGS_INTERNAL_CORDZ_UPDATE_TRACKER_H_

#include <atomic>
#include <cstdint>

#include "absl/base/config.h"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace cord_internal {

// CordzUpdateTracker tracks counters for Cord update methods.
//
// The purpose of CordzUpdateTracker is to track the number of calls to methods
// updating Cord data for sampled cords. The class internally uses 'lossy'
// atomic operations: Cord is thread-compatible, so there is no need to
// synchronize updates. However, Cordz collection threads may call 'Value()' at
// any point, so the class needs to provide thread safe access.
//
// This class is thread-safe. But as per above comments, all non-const methods
// should be used single-threaded only: updates are thread-safe but lossy.
class CordzUpdateTracker { … };

}  // namespace cord_internal
ABSL_NAMESPACE_END
}  // namespace absl

#endif  // ABSL_STRINGS_INTERNAL_CORDZ_UPDATE_TRACKER_H_