Thread（简单使用）

/***
thread.c
***/
#include<stdio.h>
#include<stdlib.h>
#include<pthread.h>

void print_message_function(void* ptr);

int main()
{
    int tmp1,tmp2;
    void* retval;
    pthread_t thread1,thread2;
    char* message1 = "thread1";
    char* message2 = "thread2";
    
    int ret_thrd1,ret_thrd2;
    ret_thrd1 = pthread_create(&thread1,NULL,(void*)&print_message_function,(void*)message1);
    ret_thrd2 = pthread_create(&thread2,NULL,(void*)&print_message_function,(void*)message2);
    
    if(ret_thrd1 != 0)
    {
        printf("create thread 1 failed
");
    }
    else
    {
        printf("create thread 1 success
");
    }

    if(ret_thrd2 != 0)
    {
        printf("create thread 2 failed
");
    }
    else
    {
        printf("create thread 2 success
");
    }

    tmp1 = pthread_join(thread1,&retval);
    printf("thread1 return value(retval) is %d
",(int)retval);
    printf("thread1 return value(tmp) is %d
",tmp1);
    if(tmp1 != 0)
    {
        printf("cannot join with thread1
");
    }
    printf("thread1 end
");

    tmp2 = pthread_join(thread2,&retval);
    printf("thread2 return value(retval) is %d
",(int)retval);
    printf("thread2 return value(tmp) is %d
",tmp2);
    if(tmp2 != 0)
    {
        printf("cannot join with thread2
");
    }
    printf("thread2 end
");
    return 0;
}

void print_message_function(void* ptr)
{
    int i;
    for(i = 0; i < 5; i++)
    {
        printf("%s:%d
",(char*)ptr,i);
    }
}

运行结果:

exbot@ubuntu:~/wangqinghe/thread/thread_0530$ ./thread
create thread 1 success
create thread 2 success
thread2:0
thread2:1
thread2:2
thread2:3
thread2:4
thread1:0
thread1:1
thread1:2
thread1:3
thread1:4
thread1 return value(retval) is 10
thread1 return value(tmp) is 0
thread1 end
thread2 return value(retval) is 10
thread2 return value(tmp) is 0
thread2 end

/***
simple example
***/
#include<stdio.h>
#include<pthread.h>

void thread(void)
{
    int i;
    for(i = 0; i < 3; i++)
    {    
        printf("This is a pthread.
");
    }
}


int main()
{
    pthread_t id;
    int i,ret;
    ret = pthread_create(&id,NULL,(void*)thread,NULL);
    if(ret != 0)
    {
        printf("Create pthread error!
");
        exit(1);
    }
    for(i = 0; i < 3; i++)
    {
        printf("This is the main process.
");
    }
    pthread_join(id,NULL);
    return 0;
}

运行结果：

exbot@ubuntu:~/wangqinghe/thread/thread_0530$ ./thread1
This is the main process.
This is the main process.
This is the main process.
This is a pthread.
This is a pthread.
This is a pthread.

/***
pthread.c
***/
//gcc pthread.c -o pthread -lpthread
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
#include<pthread.h>

void * print_a(void*);
void * print_b(void*);

int main()
{
    pthread_t t0;
    pthread_t t1;
    
    if(pthread_create(&t0,NULL,print_a,NULL) == -1)
    {
        puts("fail to create pthread t0");
        exit(1);
    }
    if(pthread_create(&t1,NULL,print_b,NULL) == -1)
    {
        puts("fail to create pthread t1");
        exit(1);
    }
    void* result;
    if(pthread_join(t0,&result) == -1)
    {
        puts("fail to recollect t0");
        exit(1);
    }
    if(pthread_join(t1,&result) == -1)
    {
        puts("fail to create recollect t1");
        exit(1);
    }
    return 0;
}

void * print_a(void*)
{
    for(int i = 0; i < 10 ; i++)
    {
        sleep(1);
        puts("aa");
    }
    return NULL;
}
void * print_b(void*)
{
    for(int i = 0; i < 20; i++)
    {
        sleep(1);
        puts("bb");
    }
    return NULL;
}

运行结果：

exbot@ubuntu:~/wangqinghe/thread$ ./pthread
bb
aa
bb
aa
bb
aa
bb
aa
aa
bb
bb
aa
bb
aa
aa
bb
bb
aa
aa
bb
bb
bb
bb
bb
bb
^C

/***
no_mutex.c
***/
#include<stdio.h>
#include<stdlib.h>
#include<pthread.h>

int sharedi = 0;
void increase_num(void);

int main()
{
    int ret;
    pthread_t thrd1,thrd2,thrd3;
    ret = pthread_create(&thrd1,NULL,(void *)increase_num,NULL);
    ret = pthread_create(&thrd2,NULL,(void*)increase_num,NULL);
    ret = pthread_create(&thrd3,NULL,(void*)increase_num,NULL);
    pthread_join(thrd1,NULL);
    pthread_join(thrd2,NULL);
    pthread_join(thrd3,NULL);

    printf("sharedi = %d
",sharedi);    

    return 0;
}

void increase_num(void)
{
    long i,tmp;
    for(i = 0 ; i  < 1000; i++)
    {
        tmp = sharedi;
        tmp = tmp + 1;
        sharedi = tmp;
    }
}

运行结果：

exbot@ubuntu:~/wangqinghe/thread/thread_0611$ ./no_mutex
sharedi = 3000