线程之间的通信socketpair【学习笔记】【原创】

平台信息:
内核：linux3.1.0
系统：android5.0
平台：tiny4412

作者：庄泽彬(欢迎转载，请注明作者)

说明: 韦老师的安卓视频学习笔记

一、在一个进程中多个线程如何进行通信，主要使用的是socketpair的机制，详细代码如下:

#include <pthread.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>          /* See NOTES */
#include <sys/socket.h>


#define SOCKET_BUFFER_SIZE      (32768U)
#define BUF_MAX_LEN              512

void *function_thread (void *arg)
{
    int fd = (int)arg;
    char buf[BUF_MAX_LEN];
    int cnt = 0;
    int len = -1;
    

    while(1)
    {
        len = sprintf(buf,"Hello,main thread1, cnt = %d
",cnt++);
        write(fd,buf,len);

        len = read(fd,buf,BUF_MAX_LEN);
        buf[len] = '';
        printf("thead1 read:%s
",buf);

        sleep(5);
    }
    

    return NULL;
}


int main(int argc,char **argv)
{
    int ret = -1;
    int sockets[2];
    int bufferSize = SOCKET_BUFFER_SIZE;
    pthread_t threadID;
    char buf[BUF_MAX_LEN];
    int len = 0;
    int cnt = 0;
    int fd = -1;

    ret = socketpair(AF_UNIX,SOCK_SEQPACKET,0,sockets);
    if(ret){
        printf("Error socketpair
");
        return -1;
    }

    setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
    setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));
    setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &bufferSize, sizeof(bufferSize));
    setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));

    ret = pthread_create(&threadID,NULL,function_thread,(void *)sockets[1]);

    fd = sockets[0];

    while(1){
        len = read(fd,buf,BUF_MAX_LEN);
        buf[len] = '';
        printf("Main thread read:%s
",buf);

        len = sprintf(buf,"Hello,thread1, cnt = %d
",cnt++);
        write(fd,buf,len);    
    }

    return 0;
}

编译方法:gcc -o socketpair socketpair.c -lpthread

二、实验现象:

三、如下图所示socketpair的进程号为5919,在这个进程下面有两个线程运行。