CUThreadPool.h

//
//  CUThreadPool.h
//  Cornell Extensions to Cocos2D
//
//  Module for a pool of threads capable of executing asynchronous tasks.  Each task
//  is specified by a void function.  There are no guarantees about thread safety;
//  that is responsibility of the author of each task.
//
//  This code is largely taken from the Cocos2d file AudioEngine.cpp, from the code
//  for asynchronous asset loading.  There was no need to couple this tool with that
//  class, so we have pulled it out (with some notable safety changes) into a general
//  purpose tool.
// 
//  Author: Walker White
//  Version: 12/3/15
//
#ifndef __CU_THREAD_POOL_H__
#define __CU_THREAD_POOL_H__

#include <stdio.h>
#include <condition_variable>
#include <queue>
#include <vector>
#include <cocos2d.h>

NS_CC_BEGIN

#pragma mark -
#pragma mark Thread Pool

class CC_DLL ThreadPool : public Ref {
private:
    CC_DISALLOW_COPY_AND_ASSIGN(ThreadPool);

protected:
    std::vector<std::thread>  _workers;
    std::queue< std::function<void()> > _taskQueue;
    
    std::mutex _queueMutex;
    std::condition_variable _taskCondition;
    
    bool _detach;
    bool _stop;
    int _complete;
    
    void threadFunc();
    
    
public:
#pragma mark Static Constructors

    static ThreadPool* create(int threads = 4);
    
    
#pragma mark Task Management

    void addTask(const std::function<void()> &task);
    
    void stop();
    
    bool isStopped() const { return _stop; }
    
    bool isShutdown() const { return _workers.size() == _complete; }

    
#pragma mark -
#pragma mark Initializers
CC_CONSTRUCTOR_ACCESS:
    ThreadPool();
    
    ~ThreadPool();
    
    virtual bool init(int threads = 4);
    
};

NS_CC_END
#endif /* defined(__CU_THREAD_POOL_H__) */