• 和菜鸟一起深入学习国嵌实验之线程编程


    1、 线程创建

    代码:

    #include <stdio.h>
    #include <string.h>
    #include <stdlib.h>
    #include <fcntl.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <unistd.h>
    #include <errno.h>
    #include <math.h>
    #include <pthread.h>
     
    struct member
    {
       int a;
       char *s;
    };
     
    void *create(void *arg)
    {
       struct member *temp;
      
       temp = (struct member *)arg;
       printf("member->a : %d\n", temp->a);
       printf("member->s : %s\n", temp->s);
      
       return (void*)0;
    }
     
    int main(int argc, char *argv[])
    {
       int error;
       pthread_t tidp;
       struct member *b;
     
        b= (struct member *)malloc(sizeof(struct member));
       b->a = 4;
       b->s = "eastmoon";
     
       error = pthread_create(&tidp, NULL, create, (void*)b);
       if(error)
        {
           printf("pthread is not create...\n");
            return -1;
        }
       
       sleep(1);
       printf("pthread is created...\n");
     
       return 0;
    }
     
     

    Makefile:

    CC = gcc
     
    CURTDIR = $(shell pwd)
    TARGET = mythread
     
    %.o:%.c
           $(CC)-c $(EXTRAFLAGS) $< -o $@
    %.o:%.S
           $(CC)-c $(EXTRAFLAGS) $< -o $@
     
    .PHONY: all clean
     
    $(TARGET): $(TARGET).o
           $(CC)  -o $@ $^ -lpthread
     
    clean:
           rm-rf $(TARGET) $(TARGET).o


    运行结果:

    eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.1$ make
    gcc -c  mythread.c -o mythread.o
    gcc  -o mythread mythread.o -lpthread
    
    
    eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.1$ ls
    Makefile  mypipe.txt  mythread  mythread.c  mythread.o
    
    
    eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.1$ ./mythread 
    member->a : 4
    member->s : eastmoon
    pthread is created...
    
    
    


    2、 线程等待

    代码:

    #include <stdio.h>
    #include <string.h>
    #include <stdlib.h>
    #include <fcntl.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <unistd.h>
    #include <errno.h>
    #include <math.h>
    #include <pthread.h>
     
    void *create(void *arg)
    {  
       int i;
       
       for(i = 0; i < 3; i++)
        {
           sleep(2);
           printf("This in the thread :%d\n", i);
        }
       
       return NULL;
    }
     
    int main(int argc, char *argv[])
    {
       pthread_t pth;
       int i, ret;
     
       ret = pthread_create(&pth, NULL, create, NULL);
       if(ret)
        {
           printf("pthread is not create...\n");
           return -1;
        }
      
       pthread_join(pth, NULL);
     
       printf("thread was exit\n");
      
       for(i = 0; i < 3; i++)
        {
           sleep(1);
           printf("This in the main: %d\n", i);
        }
     
       return 0;
    }

     

    Makefile:

    CC = gcc

     

    CURTDIR = $(shell pwd)

    TARGET = mythread_join

     

    %.o:%.c

           $(CC)-c $(EXTRAFLAGS) $< -o $@

    %.o:%.S

           $(CC)-c $(EXTRAFLAGS) $< -o $@

     

    .PHONY: all clean

     

    $(TARGET): $(TARGET).o

           $(CC)  -o $@ $^ -lpthread

     

    clean:

           rm-rf $(TARGET) $(TARGET).o

     

    运行结果:

    eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.2$make
    gcc -c mythread_join.c -o mythread_join.o
    gcc -o mythread_join mythread_join.o -lpthread
     
    eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.2$ls
    Makefile mythread_join mythread_join.c  mythread_join.o
     
    eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.2$./mythread_join
    This in the thread :0
    This in the thread :1
    This in the thread :2
    thread was exit
    This in the main: 0
    This in the main: 1
    This in the main: 2

    总结:运行程序后,在没有调用thread_join之前线程和进程是同时运行的,调用了thread_join之后进程阻塞直到线程退出。

      

    3、 线程退出保护设计

    代码:

    #include <stdio.h>
    #include <string.h>
    #include <stdlib.h>
    #include <fcntl.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <unistd.h>
    #include <errno.h>
    #include <math.h>
    #include <pthread.h>
     
    void *clean(void *arg)
    {  
       printf("cleanup: %s\n", (char *)arg);
       
       return (void *)0;
       
    }
     
    void *thr_fn1(void *arg)
    {
       printf("thread 1 start \n");
       
       pthread_cleanup_push((void *)clean, "thread 1 first handler");
       pthread_cleanup_push((void *)clean, "thread 1 secondhandler");
       
       printf("thread 1 push complete\n");
     
       if(arg)
        {
           return (void*)1;
        }
     
       pthread_cleanup_pop(0);
       pthread_cleanup_pop(0);
     
       return (void *)1;
     
    }
     
    void *thr_fn2(void *arg)
    {
       printf("thread 2 start \n");
       
       pthread_cleanup_push((void *)clean, "thread 2 first handler");
       pthread_cleanup_push((void *)clean, "thread 2 secondhandler");
       
       printf("thread 2 push complete\n");
     
       if(arg)
        {
           pthread_exit((void *)2);
        }
     
       pthread_cleanup_pop(0);
       pthread_cleanup_pop(0);
     
       pthread_exit((void *)2);
     
    }
    int main(int argc, char *argv[])
    {
       pthread_t tid1, tid2;
       int i, ret;
       void *tret;
     
       ret = pthread_create(&tid1, NULL, thr_fn1, (void *)1);
       if(ret)
        {
           printf("pthread 1 is not create...\n");
           return -1;
        }
      
       ret = pthread_create(&tid2, NULL, thr_fn2, (void *)1);
       if(ret)
        {
           printf("pthread 2 is not create...\n");
           return -1;
        }
      
       ret = pthread_join(tid1, &tret);
       if(ret)
        {
           printf("pthread 1 join error......\n");
           return -1;
        }
     
       printf("thread 1 exit code %d\n", (int)tret);
      
       ret = pthread_join(tid2, &tret);
       if(ret)
        {
           printf("pthread 2 join error......\n");
           return -1;
        }
     
       printf("thread 2 exit code %d\n", (int)tret);
      
       return 0;
    }
     


    Makefile:

    CC = gcc
     
    CURTDIR = $(shell pwd)
    TARGET = mythread_clean
     
    %.o:%.c
           $(CC)-c $(EXTRAFLAGS) $< -o $@
    %.o:%.S
           $(CC)-c $(EXTRAFLAGS) $< -o $@
     
    .PHONY: all clean
     
    $(TARGET): $(TARGET).o
           $(CC)  -o $@ $^ -lpthread
     
    clean:
           rm-rf $(TARGET) $(TARGET).o
     
     


    运行结果:

    eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.3$make
    gcc -c mythread_clean.c -o mythread_clean.o
    gcc -o mythread_clean mythread_clean.o -lpthread
     
    eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.3$ls
    Makefile mythread_clean mythread_clean.c  mythread_clean.o
     
    eastmoon@eastmoon-virtual-machine:~/work/guoqian/3/3.3$./mythread_clean
    thread 2 start
    thread 2 push complete
    cleanup: thread 2 second handler
    cleanup: thread 2 first handler
    thread 1 start
    thread 1 push complete
    thread 1 exit code 1
    thread 2 exit code 2 

    总结:由运行结果可知,线程1是return退出的,所以不运行线程清理函数,而线程2是pthread_exit退出的,所以执行了线程清理函数。

  • 相关阅读:
    验证手机和电话号码
    oracle取字符串长度的函数length()和hengthb()
    AngularJs教程
    nop commerce文档
    根据子查询批量删除的sql语句
    AngularJs赋值问题
    PetaPoco模糊查询
    js转换 /Date(1464671903000)/ 格式的日期的方法
    jquery-cookie插件怎么读写json数据
    executssql 函数的每一句代码的意思
  • 原文地址:https://www.cnblogs.com/wuyida/p/6300019.html
Copyright © 2020-2023  润新知