多线程编程实例

来源：互联网发布：光纤网络监控方案编辑：程序博客网时间：2024/06/05 17:42

有四个线程1、2、3、4。线程1的功能就是输出1，线程2的功能就是输出2，以此类推.........现在有四个文件ABCD。初始都为空。现要让四个文件呈如下格式：

A：1 2 3 4 1 2....

B：2 3 4 1 2 3....

C：3 4 1 2 3 4....

D：4 1 2 3 4 1....

程序：

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include<unistd.h>
#include<fcntl.h>

int fd1,fd2,fd3,fd4; //之后要写的四个文件的文件描述符，定义为全局变量可所有函数都用

void *func1(void*)          //线程1执行，在四个文件中写入符号
{
    int real_w;
  int i;
  for(i = 1; i < 5; i++)
  {
      real_w = write(fd1,"1",1);
      real_w = write(fd2,"2",1);
      real_w = write(fd3,"3",1);
      real_w = write(fd4,"4",1);
      if(real_w == 1)
    {
        printf("write fd1 sucessfuly\n");   //每次循环休眠一秒，此一秒内其他进程会执行
      sleep(1);
    }
  }
}
void *func2(void*)           //线程2执行，同上
{
    int real_w;
  int i;
  for(i = 1; i < 5; i++)
  {
      real_w = write(fd1,"2",1);
      real_w = write(fd2,"3",1);
      real_w = write(fd3,"4",1);
      real_w = write(fd4,"1",1);
      if(real_w == 1)
    {
        printf("write fd2 sucessfuly\n");
      sleep(1);
    }
  }
}
void *func3(void*)           //线程3执行，同上
{
    int real_w;
  int i;
  for(i = 1; i < 5; i++)
  {
      real_w = write(fd1,"3",1);
      real_w = write(fd2,"4",1);
      real_w = write(fd3,"1",1);
      real_w = write(fd4,"2",1);
      if(real_w == 1)
    {
        printf("write fd3 sucessfuly\n");
      sleep(1);
    }
  }
}
void *func4(void*)        //线程4执行，同上
{
    int real_w;
  int i;
  for(i = 1; i < 5; i++)
  {
      real_w = write(fd1,"4",1);
      real_w = write(fd2,"1",1);
      real_w = write(fd3,"2",1);
      real_w = write(fd4,"3",1);
      if(real_w == 1)
    {
        printf("write fd4 sucessfuly\n");
      sleep(1);
    }
  }
}
int main()
{
   int ret;
pthread_t id1,id2,id3,id4;
fd1 = open("A.text",O_CREAT|O_RDWR,0644);    //打开A,B,C,D四个文件，并进行错误处理
if (-1 == fd1)
{
    printf("open A fail");
  exit(-1);
}
fd2 = open("B.text",O_CREAT|O_RDWR,0644);
if (-1 == fd1)
{
    printf("open B fail");
  exit(-1);
}
fd3 = open("C.text",O_CREAT|O_RDWR,0644);
if (-1 == fd1)
{
    printf("open c fail");
  exit(-1);
}
fd4 = open("D.text",O_CREAT|O_RDWR,0644);
if (-1 == fd1)
{
    printf("open D fail");
  exit(-1);
}
ret = pthread_create(&id1,NULL,func1,NULL);
if (-1 == ret)
{
      printf("create thread fail");
      exit(-1);
}
ret = pthread_create(&id2,NULL,func2,NULL);
if (-1 == ret)
{
      printf("create thread fail");
      exit(-1);
}
ret = pthread_create(&id3,NULL,func3,NULL);
if (-1 == ret)
{
      printf("create thread fail");
      exit(-1);
}
ret = pthread_create(&id4,NULL,func4,NULL);
if (-1 == ret)
{
      printf("create thread fail");
      exit(-1);
}

   pthread_join(id1,NULL);         //等待线程结束，必须有，否则进程结束，所以线程未结束也将结束
   pthread_join(id2,NULL);
   pthread_join(id3,NULL);
   pthread_join(id4,NULL);

return 0;
}

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