threadpool.h

#ifndef THREADPOOL_H
#define THREADPOOL_H

#include <list>
#include <deque>
#include <cstdio>
#include <exception>
#include <pthread.h>

#include "locker.h"

template <typename T>
class threadpool
{
public:
    threadpool( int thread_number = 8, int max_requests = 10000);
    ~threadpool();

    bool append(T * request);

private:
    static void* worker(void* arg);
    void run();

private:
    int m_thread_number;
    int  m_max_requests;
    pthread_t * m_threads;
    std::deque<T*> m_workqueue;
    locker m_queuelocker;
    sem m_queuestat;
    bool  m_stop;
};




template<typename T>
threadpool<T>::threadpool(int thread_number, int max_request)
                :m_thread_number(thread_number),m_max_requests(max_request),
                m_stop(false),m_threads(NULL)
{
    if((thread_number <= 0) || (max_request <= 0) )
    {
        throw std::exception();
    }

    m_threads = new pthread_t [m_thread_number];
    if(!m_threads)
    {
        throw std::exception();
    }

    for(int i = 0; i<m_thread_number;  ++i)
    {
        printf("create the %dth thread\n",i);
        if(pthread_create(m_threads+i,NULL,worker,this))
        {   
            printf("create threads fail\n");
            delete [] m_threads;
            throw  std::exception();
        }
        if(pthread_detach(m_threads[i]))
        {
            printf("detach threads fail\n");
            delete [] m_threads;
            throw  std::exception();           
        }
    }
}


template<typename T>
threadpool<T>::~threadpool()
{
    delete [] m_threads;
    m_stop = true;
}

template<typename T>
bool threadpool<T>::append(T * request)
{
    m_queuelocker.lock();
    if( m_workqueue.size() > m_max_requests )
    {
        printf("append request fail, we got too much requests in queue\n");
        m_queuelocker.unlock();
        return false;
    }
    m_workqueue.push_back(request);
    m_queuelocker.unlock();
    m_queuestat.post();
    return true;
}

template<typename T>
void* threadpool<T>::worker(void *arg)
{
    threadpool * pool = (threadpool*) arg;
    pool->run();
    return pool;
}

template<typename T>
void threadpool<T>::run()
{
    while (! m_stop)
    {
        m_queuestat.wait();
        m_queuelocker.lock();
        if( m_workqueue.empty())
        {
            m_queuelocker.unlock();
            continue;
        }
        T* request = m_workqueue.front();
        m_workqueue.pop_front();
        m_queuelocker.unlock();
        if( ! request)
        {
            printf("got a empty request\n");
            continue;
        }
        request->process();
        printf("process finished, wait another request\n");
    }
}





#endif