socketpair與管道pipe

在看Android 輸入系統的時候，第一次看到socketpair，發現和管道非常相似。唯他們的差別就是socketpair，預設支援全雙工，而pipe是半雙工的。他們一樣隻能用在父子程序或者線程之間通信。

下面分别以socketpair和管道實作全雙工通信。

管道實作線程間全雙工通信

#include<stdio.h>
#include<pthread.h>
#include<string.h>
#include<stdlib.h>
#include<unistd.h>

#define SIZE 1024

int fd1[],fd2[]; //fd1[]:read,  fd1[]:write

void *func_thread1(void *arg)
{
    char buf[SIZE] = {0};
    int cnt = ;
    while()
    {
        sprintf(buf,"hello main  %d\n",cnt++);
        write(fd1[],buf,strlen(buf));
        int len = read(fd2[],buf,SIZE);
        buf[len] = '\0';
        printf("%s",buf);
        bzero(buf,SIZE);
        sleep();
    }
    return NULL;
}

int main(int agrc,char**argv)
{
    pthread_t thread1_t;

    /*1. create pipe*/
    pipe(fd1);
    pipe(fd2);
    /*2. create thread1*/
    pthread_create(&thread1_t, NULL,
                          func_thread1, NULL);
    char buf[SIZE] = {0};
    int cnt = ;
    char * p = buf;
    printf("buf[SIZE] sizeof:%d,  strlen:%d\n",sizeof(buf),strlen(buf));
    printf(" char * p  sizeof:%d,  strlen:%d\n",sizeof(p),strlen(p));
    while(){
        int len = read(fd1[],buf,SIZE);
        buf[len] = '\0';
        printf("%s",buf);
        bzero(buf,SIZE);
        sprintf(buf,"hello thread  %d\n",cnt++);
        write(fd2[],buf,strlen(buf));  
        sleep();
    }
    return ;
}

           

Socketpair實作線程間全雙工通信

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

#define SIZE 1024

void *func_thread1(void *arg)
{
    char buf[SIZE] = {};
    int cnt = ;
    int fd = (int)arg;
    while()
    {
        sprintf(buf,"hello main  %d\n",cnt++);
        write(fd,buf,strlen(buf));
        int len = read(fd,buf,SIZE);
        buf[len] = '\0';
        printf("%s",buf);
        bzero(buf,SIZE);
        sleep();
    }
    return NULL;
}

int main(int agrc,char**argv)
{
    int fd[];
    pthread_t thread1_t;

    /*1. create socketpair*/
    int ret = socketpair(AF_UNIX,SOCK_STREAM,,fd);
    if(ret < ){
        perror("socketpair");
        exit(-);
    }
    /*2. create thread1*/
    pthread_create(&thread1_t, NULL,
                          func_thread1, fd[]);
    char buf[SIZE] = {};
    int cnt = ;
    char * p = buf;

    while(){
        int len = read(fd[],buf,SIZE);
        buf[len] = '\0';
        printf("%s",buf);
        bzero(buf,SIZE);
        sprintf(buf,"hello thread  %d\n",cnt++);
        write(fd[],buf,strlen(buf));   
        sleep();
    }
    return ;
}