Asio_1

参考来源https://www.gamedev.net/blogs/entry/2249317-a-guide-to-getting-started-with-boostasio/

Example 1a

#include <iostream>
#include <asio.hpp>

int main(int argc,char * argv[]){
    asio::io_service io_service;
    io_service.run();
    std::cout<<"display"<<std::endl;

    return 0;

}

结果输出：

test.png

Example 1b

#include <iostream>
#include <asio.hpp>

int main(int argc,char * argv[]){
    asio::io_service io_service;
    asio::io_service::work work(io_service);
    io_service.run();
    std::cout<<"display"<<std::endl;

    return 0;

}

程序会阻塞在run函数中。结果输出：

work.png

Example 1c

#include <iostream>
#include <asio.hpp>

int main(int argc,char * argv[]){
    asio::io_service io_service;
    io_service.poll();
    std::cout<<"display"<<std::endl;

    return 0;

}

结果输出：

image.png

Example 1d

#include <iostream>
#include <asio.hpp>

int main(int argc,char * argv[]){
    asio::io_service io_service;
    asio::io_service::work work(io_service);
    io_service.poll();
    std::cout<<"display"<<std::endl;

    return 0;

}

相比调用run()，程序并不会会阻塞。结果输出：

image.png

Example 1e

#include <iostream>
#include <asio.hpp>

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

    work.reset();
    io_service.run();
    std::cout<<"display"<<std::endl;

    return 0;

}

清空对象后，程序并不阻塞。

image.png

Example 1f

#include <iostream>
#include <asio.hpp>
#include <pthread.h>


 asio::io_service io_service;
void *workerThread(void * arg){
    std::cout<<pthread_self()<<" start"<<std::endl;
    io_service.run();
    std::cout<<pthread_self()<<" end"<<std::endl;
    return (void *)0;
}

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

    std::cout<<"Press Enter to exit"<<std::endl;
    pthread_t ntid[4];
    for(int i=0;i<4;i++)
    {
        pthread_create(&ntid[i],NULL,workerThread,NULL);
    }

    std::cin.get();
    io_service.stop();

    for(inti=0;i<4;i++){
        pthread_join(ntid[i],NULL);
    }

    return 0;

}

结果如下

image.png