/*
 * =====================================================================================
 *
 *       Filename:  shm_queue.h
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年03月25日 10时35分09秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), 
 *   Organization:  
 *
 * =====================================================================================
 */

#ifndef SHM_QUEUE_JE0OEUP3
#define SHM_QUEUE_JE0OEUP3

#include "shm.h"
#include <atomic>
#include <chrono>

namespace bhome_shm
{

template <class D>
using Circular = robust::CircularBuffer<D, Allocator<D>>;


template <class D>
class SharedQueue
{
public:
	SharedQueue(const uint32_t len, Allocator<D> const &alloc) :
	    queue_(len, alloc) {}

	template <class OnWrite>
	bool TryWrite(const D &d, const OnWrite &onWrite)
	{
		Guard lock(mutex());
		if (!queue_.full()) {
			onWrite(d);
			queue_.push_back(d);
			return true;
		} else {
			return false;
		}
	}

	bool TryWrite(const D &d)
	{
		Guard lock(mutex());
		return !queue_.full() ? (queue_.push_back(d), true) : false;
	}

	bool Read(D &d, const int timeout_ms)
	{
		using namespace std::chrono;
		auto end_time = steady_clock::now() + milliseconds(timeout_ms);
		do {
			if (TryRead(d)) {
				return true;
			} else {
				robust::QuickSleep();
			}
		} while (steady_clock::now() < end_time);
		return false;
	}
	bool TryRead(D &d)
	{
		Guard lock(mutex());
		if (!queue_.empty()) {
			queue_.pop_front(d);
			return true;
		} else {
			return false;
		}
	}

private:
	typedef Circular<D> Queue;
	Queue queue_;
	Mutex mutex_;
	Mutex &mutex() { return mutex_; }
};

} // namespace bhome_shm

#endif // end of include guard: SHM_QUEUE_JE0OEUP3