Question

我目前正在学习如何使用和实现boost :: asio。我一直在＆＃34; https://www.gamedev.net/blogs/entry/2249317-a-guide-to-getting-started-with-boostasio/＆＃34;

上关注gamedev.net上的教程

在本教程中，将显示以下代码：

#include <iostream>
#include "/usr/include/boost/asio.hpp"
#include "/usr/include/boost/thread.hpp"
#include "/usr/include/boost/lexical_cast.hpp"

boost::mutex global_stream_lock;

void WorkerThread( boost::shared_ptr< boost::asio::io_service > io_service )
{
    global_stream_lock.lock();
    std::cout << "[" << boost::this_thread::get_id() << "] Thread Start" << std::endl;
    global_stream_lock.unlock();

    io_service->run();

    global_stream_lock.lock();
    std::cout << "[" << boost::this_thread::get_id() << "] Thread Finish" << std::endl;
    global_stream_lock.unlock();


}

void PrintNum( int x )
{
    std::cout << "[" << boost::this_thread::get_id() << "] x: " << x << std::endl;

}

int main( int argc, char * argv[] )
{
    boost::shared_ptr< boost::asio::io_service > io_service(
            new boost::asio::io_service
    );
    boost::shared_ptr< boost::asio::io_service::work > work(
            new boost::asio::io_service::work( *io_service )
    );
    boost::asio::io_service::strand strand (*io_service);


    global_stream_lock.lock();
    std::cout << "[" << boost::this_thread::get_id()
              << "] The program will exit when all work has finished." << std::endl;
    global_stream_lock.unlock();

    boost::thread_group worker_threads;
    for( int x = 0; x < 2; ++x )
    {
        worker_threads.create_thread( boost::bind( &WorkerThread, io_service ) );

    }


    boost::this_thread::sleep( boost::posix_time::milliseconds( 1000 ) );

    strand.post( boost::bind( &PrintNum, 1 ) );
    strand.post( boost::bind( &PrintNum, 2 ) );
    strand.post( boost::bind( &PrintNum, 3 ) );
    strand.post( boost::bind( &PrintNum, 4 ) );
    strand.post( boost::bind( &PrintNum, 5 ) );

    work.reset();

    worker_threads.join_all();

    return 0;
}

执行上述代码时的输出：

[7fef17715000] The program will exit when all work has finished.
[7fef15897700] Thread Start
[7fef16098700] Thread Start
[7fef15897700] x: 1
[7fef15897700] x: 2
[7fef15897700] x: 3
[7fef15897700] x: 4
[7fef15897700] x: 5
[7fef15897700] Thread Finish
[7fef16098700] Thread Finish

我的问题是上面的代码只使用thread_id 7fef15897700并且从未使用过7fef16098700。在示例教程中，输出显示如下：

[00154F88] The program will exit when all work has finished.
[001532B0] Thread Start
[00154FB0] Thread Start
[001532B0] x: 1
[00154FB0] x: 2
[001532B0] x: 3
[00154FB0] x: 4
[001532B0] x: 5
[00154FB0] Thread Finish
[001532B0] Thread Finish

我正在使用libboost 1.66，它的构建方式如下：

./bootstrap.sh --prefix=/usr
./b2 install threading=multi

我正在运行debian，如下所示：

PRETTY_NAME="Debian GNU/Linux 9 (stretch)"
NAME="Debian GNU/Linux"
VERSION_ID="9"
VERSION="9 (stretch)"
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

＆＃34; lscpu | grep -i cpu＆＃34;输出：

CPU op-mode(s):        32-bit, 64-bit
CPU(s):                4
On-line CPU(s) list:   0-3
CPU family:            6
Model name:            Intel(R) Core(TM) i5 CPU         650  @ 3.20GHz
CPU MHz:               1197.000
CPU max MHz:           3193.0000
CPU min MHz:           1197.0000
NUMA node0 CPU(s):     0-3

如何让代码使用thread_group中的所有可用线程？

感谢您提供任何帮助或意见。

使用带有thread_group的strand的boost :: asio只使用thread_group中的第一个线程

0 个答案: