| /** |
| * 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. |
| */ |
| |
| #include "Semaphore.h" |
| |
| namespace pulsar { |
| |
| Semaphore::Semaphore(uint32_t limit) : limit_(limit), currentUsage_(0), mutex_(), condition_() {} |
| |
| bool Semaphore::tryAcquire(int n) { |
| std::lock_guard<std::mutex> lock(mutex_); |
| |
| if (currentUsage_ + n > limit_) { |
| return false; |
| } else { |
| currentUsage_ += n; |
| return true; |
| } |
| } |
| |
| bool Semaphore::acquire(int n) { |
| std::unique_lock<std::mutex> lock(mutex_); |
| |
| while (currentUsage_ + n > limit_) { |
| if (isClosed_) { |
| return false; |
| } |
| condition_.wait(lock); |
| } |
| |
| currentUsage_ += n; |
| return true; |
| } |
| |
| void Semaphore::release(int n) { |
| std::unique_lock<std::mutex> lock(mutex_); |
| currentUsage_ -= n; |
| lock.unlock(); |
| |
| if (n == 1) { |
| condition_.notify_one(); |
| } else { |
| condition_.notify_all(); |
| } |
| } |
| |
| uint32_t Semaphore::currentUsage() const { |
| std::lock_guard<std::mutex> lock(mutex_); |
| return currentUsage_; |
| } |
| |
| void Semaphore::close() { |
| std::unique_lock<std::mutex> lock(mutex_); |
| isClosed_ = true; |
| condition_.notify_all(); |
| } |
| |
| } // namespace pulsar |