62 lines
1.6 KiB
C
62 lines
1.6 KiB
C
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/**
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* Copyright (c) 2012 by Matthias Noack, Zuse Institute Berlin
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*
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* Licensed under the BSD License, see LICENSE file for details.
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*
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* This specific file is based on an example found in this article:
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* http://www.quantnet.com/cplusplus-multithreading-boost/
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*/
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#ifndef CPP_INCLUDE_UTIL_SYNCHRONIZED_QUEUE_H_
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#define CPP_INCLUDE_UTIL_SYNCHRONIZED_QUEUE_H_
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#include <boost/thread/thread.hpp>
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#include <queue>
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namespace xtreemfs {
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namespace util {
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/** Queue class that has thread synchronization. Intended to synchronize
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* threads in a producer consumer scenario.*/
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template <typename T>
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class SynchronizedQueue {
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public:
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/** Add data to the queue and notify others. Never blocks. */
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void Enqueue(const T& data) {
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boost::mutex::scoped_lock lock(mutex_);
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queue_.push(data);
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// Notify others that data is ready
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queue_not_empty_cond_.notify_one();
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}
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/** Get data from the queue. Blocks if no data is available. */
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T Dequeue() {
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boost::mutex::scoped_lock lock(mutex_);
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// When there is no data, wait till someone fills it.
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// Lock is automatically released in the wait and obtained
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// again after the wait
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while (queue_.size() == 0) {
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queue_not_empty_cond_.wait(lock);
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}
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T result = queue_.front();
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queue_.pop();
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return result;
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}
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private:
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/** STL queue for data storage. */
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std::queue<T> queue_;
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/** The mutex to synchronize queue access. */
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boost::mutex mutex_;
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/** The condition to wait for if the queue is empty. */
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boost::condition_variable queue_not_empty_cond_;
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};
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} // namespace util
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} // namespace xtreemfs
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#endif
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