使用C++实现线程池报错，std::thread

Question

1. 我想用C++实现一个线程池，有2个文件：一个是thread.cpp,还有一个是threadpool_test.cpp。thread.cpp有2个类，一个是threadpool,还有一个是Task。threadpool_test.cpp是调用文件。他们编译的时候报错，目前还是没有解决。下面是代码。

2. 声明和实现

//threadp.cpp
#include<stdio.h>
#include<iostream>
#include<sys/types.h>
#include<vector>
#include<thread>
#include<pthread.h>
#include<stdlib.h>
#include<mutex>
#include<string.h>
#include<condition_variable>
using namespace std;

class Task
{
    protected:
        char * TaskName;
        void * TaskData;
    public:
        Task();
        Task( char * TName );
        virtual int Run() = 0;
        void SetData( void * TData );
        void showdata();
        virtual ~Task() {};
};

template<class TASK>
class ThreadPool
{
    private:
        int thread_num;
        vector<TASK *> TaskList;
        vector<thread> threads;
        bool shutdown;

        mutex _x;
        condition_variable  _cond;

    public:
        ThreadPool( int ThN = 10 );
        int GetTaskNum();
        int PushTask( TASK * task );
        int StopAll();
        int Create();

        void * ThreadFun();
};

template<class TASK>
int ThreadPool<TASK>::Create()
{
    for( int i = 0; i < thread_num; i++ )
        threads.push_back( thread( &ThreadPool<TASK>::ThreadFun ) );//line54
        return 0;
}

template<class TASK>
ThreadPool<TASK>::ThreadPool( int ThN ):thread_num(ThN)
{
    shutdown = false;
    cout << thread_num  << " numbers threads will be create." << endl;
    Create();    //line 63
}

template<class TASK>
int ThreadPool<TASK>::GetTaskNum()
{
    return TaskList.size();
}

template<class TASK>
int ThreadPool<TASK>::PushTask( TASK * task )
{
    unique_lock<mutex> locker( _x );
    TaskList.push_back( task );
    _x.unlock();
    _cond.notify_one();
    return 0;
}

template<class TASK>
void * ThreadPool<TASK>::ThreadFun()
{
    thread::id tid = std::this_thread::get_id();
    while(1) {
        unique_lock<mutex> locker( _x );
        while( TaskList.size() == 0 && !shutdown )
            _cond.wait( locker );
        if( shutdown ) {
            locker.unlock( );
            printf("Thread %lu will exit.\n",tid);
            return (void *)0;
        }
        typename vector<TASK>::iterator iter = TaskList.begin();
        if( iter != TaskList .end() ) {
            TASK task = *iter;
            TaskList.erase( iter );
            locker.unlock( );
            task.Run();
            printf("%lu idle.\n",tid);
        }
     }
     return (void *)0;
}

template<class TASK>
int ThreadPool<TASK>::StopAll()
{
    if( shutdown ) return -1;
    cout << "All thread will stop." << endl;
    shutdown = true;
    _cond.notify_all();
    for( int i = 0; i < thread_num; i++ )
    threads[i].join();

    threads.clear();
    cout << "The Threadpool is stop." << endl;
    return 0;
}

Task::Task() { TaskName = NULL; TaskData = NULL; }

Task::Task( char * TName )
{
    TaskName = TName;
    TaskData = NULL;
}

void Task::SetData( void * TData )
{
    TaskData = TData;
}

void Task::showdata()
{
    cout << TaskData << endl;
}

main file

//threadpool_test.cpp
#include<iostream>
#include<vector>
#include<stdio.h>
#include<string>
#include<thread>
#include<unistd.h>
//#include "threadpool.h"
#include "threadp.cpp"
//#include "threadpool.cpp"
using namespace std;

class TaskWork : public Task
{
public:
    //Task() {}
    virtual int Run()
    {
        printf("%s\n",(char *)this->TaskData);
        sleep(5);
        return 0;
    }
};

int main()
{
    TaskWork task;
    char obj[] = "abc";
    task.SetData( obj );
    task.showdata();
    ThreadPool<TaskWork> thread_pool(10);

    for( int i = 0; i < 20; i++ )    //line 33
        thread_pool.PushTask( &task );

    while( 1 ) { 
        if( thread_pool.GetTaskNum() == 0 && thread_pool.StopAll() == -1 )     { 
            cout << "exit the main.\n";
            exit(0);
        }
    }   
    sleep(2);

    return 0;
}

编译错误信息（g++4.8 & centOS 7）:

[root@localhost 15.05]# g++ -g -lpthread -D_REENTRANT threadpool_test.cpp -o test -std=c++11 -fPIC
In file included from /usr/include/c++/4.8.2/thread:39:0,
                 from threadpool_test.cpp:6:
/usr/include/c++/4.8.2/functional: In instantiation of ‘struct         std::_Bind_simple<std::_Mem_fn<void* (ThreadPool<TaskWork>::*)()>()>’:
/usr/include/c++/4.8.2/thread:137:47: required from ‘std::thread::thread    (_Callable&&, _Args&& ...) [with _Callable = void* (ThreadPool<TaskWork>::*)(); _Args = {}]’
threadp.cpp:54:61:   required from ‘int ThreadPool<TASK>::Create() [with TASK = TaskWork]’
threadp.cpp:63:9:   required from ‘ThreadPool<TASK>::ThreadPool(int) [with     TASK = TaskWork]’
threadpool_test.cpp:33:37:   required from here
/usr/include/c++/4.8.2/functional:1697:61: error: no type named ‘type’     in ‘class std::result_of<std::_Mem_fn<void* (ThreadPool<TaskWork>::*)()>()>’
       typedef typename result_of<_Callable(_Args...)>::type result_type;
                                                         ^
/usr/include/c++/4.8.2/functional:1727:9: error: no type named ‘type’  in ‘class std::result_of<std::_Mem_fn<void* (ThreadPool<TaskWork>::*)()>()>’
         _M_invoke(_Index_tuple<_Indices...>)
         ^

Answer 1

template<class TASK>
int ThreadPool<TASK>::Create()
{
    for( int i = 0; i < thread_num; i++ )
        threads.push_back( thread( &ThreadPool<TASK>::ThreadFun, this ) );//line54 少了参数 this
        return 0;
}

Answer 2

ThreadFun需要改一下，才能够编译通过：

template<class TASK>
void * ThreadPool<TASK>::ThreadFun()
{
    thread::id tid = std::this_thread::get_id();
    while(1) {
        unique_lock<mutex> locker( _x );
        while( TaskList.size() == 0 && !shutdown )
            _cond.wait( locker );
        if( shutdown ) {
            locker.unlock( );
            printf("Thread %lu will exit.\n",tid);
            return (void *)0;
        }
        typename vector<TASK>::iterator iter = TaskList.begin();
        if( iter != TaskList.end() ) {    // 去掉.end()前的空格
            TASK task = **iter;           // 两个**
            TaskList.erase( iter );
            locker.unlock( );
            task.Run();
            printf("%lu idle.\n",tid);
        }
     }
     return (void *)0;
}