简单的线程程序

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

void *thread_function(void *arg);

char message[] = "Hello World";

int main()
{
	int res;
	pthread_t a_thread;
	void *thread_result;

	res = pthread_create(&a_thread,NULL,thread_function,(void *)message);
	if(res != 0)
	{
		perror("Thread creation failed");
		exit(EXIT_FAILURE);
	}
	printf("Waiting for thread to finish...\n");
	res = pthread_join(a_thread,&thread_result);
	if(res != 0)
	{
		perror("Thread join failed");
		exit(EXIT_FAILURE);
	}
	printf("Thread joined,it returned %s\n",(char *)thread_result);
	printf("Message is now %s\n",message);
	exit(EXIT_SUCCESS);
}

void *thread_function(void *arg)
{
	printf("thread_function is running.Argument was %s\n",(char *)arg);
	Sleep(3);
	strcpy(message,"Bye!");
	pthread_exit("Thank you for the CPU time");
}

运行这个程序

./thread1

Waiting for thread to finish...

thread_function is running.Argument was Hello World

Thread joined,it returned Thank you for the CPU time

Message is now Bye!

 

我们向pthread_create函数传递了一个pthread_t类型对象的地址，今后用它来引用这个新线程。我们不想改变默认的线程属性，所以设置第二个参数为NULL。最后两个参数分别为将要调用的函数和一个传递给该函数的参数。

如果这个调用成功了，就会有2个线程在运行。原先的线程（main）继续执行pthread_create后面的代码，而新线程开始执行thread_function函数。

pthread_join将等待它指定的线程终止后才返回。