C++11 线程安全的BlockingQueue实现

#ifndef _BLOCKINGQUEUE_H_
#define _BLOCKINGQUEUE_H_

#include <mutex>
#include <condition_variable>
#include <deque>
#include <assert.h>

template <typename T>
class BlockingQueue {
public:
using MutexLockGuard = std::lock_guard<std::mutex>;

BlockingQueue()
: _mutex(),
_notEmpty(),
_queue()
{
}

BlockingQueue(const BlockingQueue &) = delete;
BlockingQueue& operator=(const BlockingQueue &) = delete;

void put(const T &x)
{
{
MutexLockGuard lock(_mutex);
_queue.push_back(x);
}
_notEmpty.notify_one();
}

void put(T &&x)
{
{
MutexLockGuard lock(_mutex);
_queue.push_back(std::move(x));
}
_notEmpty.notify_one();
}

T take()
{
std::unique_lock<std::mutex> lock(_mutex);
_notEmpty.wait(lock, [this]{  return !this->_queue.empty(); });
assert(!_queue.empty());

T front(std::move(_queue.front()));
_queue.pop_front();

return  front;
}

size_t size() const
{
MutexLockGuard lock(_mutex);
return _queue.size();
}

private:
mutable std::mutex _mutex;
std::condition_variable _notEmpty;
std::deque<T> _queue;
};

#endif  // _BLOCKINGQUEUE_H_