| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 |
| * |
| * http://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 <atomic> |
| #include <condition_variable> |
| #include <cstdint> |
| #include <mutex> |
| |
| namespace pulsar { |
| |
| class Semaphore { |
| public: |
| explicit Semaphore(uint32_t limit); |
| |
| bool tryAcquire(int n = 1); |
| bool acquire(int n = 1); |
| void release(int n = 1); |
| uint32_t currentUsage() const; |
| |
| void close(); |
| |
| private: |
| const uint32_t limit_; |
| uint32_t currentUsage_; |
| mutable std::mutex mutex_; |
| std::condition_variable condition_; |
| bool isClosed_ = false; |
| }; |
| |
| } // namespace pulsar |