C++類的構造函數中的線程池正在死亡

Question

我有以下代碼在類的構造函數中創建線程池。線程立即創建並退出。 請幫忙。

class ThreadPool { 
public: 
    boost::asio::io_service io_service; 
    boost::thread_group threads; 
    ThreadPool(); 
    void call(); 
    void calling(); 
}; 

ThreadPool::ThreadPool() { 
    /* Create thread-pool now */ 
    size_t numThreads = boost::thread::hardware_concurrency(); 
    boost::asio::io_service::work work(io_service); 
    for(size_t t = 0; t < numThreads; t++) { 
     threads.create_thread(boost::bind(&boost::asio::io_service::run, &io_service)); 
    } 
} 

void ThreadPool::call() { 
    std::cout << "Hi i'm thread no " << boost::this_thread::get_id() << std::endl; 
}; 

void ThreadPool::calling() { 
    sleep(1); 
    io_service.post(boost::bind(&ThreadPool::call, this)); 
} 

int main(int argc, char **argv) 
{ 
    ThreadPool pool; 
    for (int i = 0; i < 5; i++) { 
    pool.calling(); 
    } 
    pool.threads.join_all(); 
    return 0; 
} 

Answer 1

的boost ::支持ASIO :: io_service對象::工作工作必須是類的成員，因此它不會被破壞。

class ThreadPool { 
public: 
    boost::asio::io_service io_service; 
    boost::thread_group threads; 
    boost::asio::io_service::work *work; 
    ThreadPool(); 
    void call(); 
    void calling(); 
    void stop() { delete work; } 
}; 

ThreadPool::ThreadPool() : work(new boost::asio::io_service::work(io_service)) { 
    /* Create thread-pool now */ 
    size_t numThreads = boost::thread::hardware_concurrency(); 
    for(size_t t = 0; t < numThreads; t++) { 
     threads.create_thread(boost::bind(&boost::asio::io_service::run, &io_service)); 
    } 
} 

void ThreadPool::call() { 
    std::cout << "Hi i'm thread no " << boost::this_thread::get_id() << std::endl; 
}; 

void ThreadPool::calling() { 
    Sleep(1000); 
    io_service.post(boost::bind(&ThreadPool::call, this)); 
} 

int main() 
{ 
    ThreadPool pool; 
    for (int i = 0; i < 5; i++) { 
    pool.calling(); 
    } 
    pool.stop(); 
    pool.threads.join_all(); 
    return 0; 
}