void *send_thread(void )
{
pthread_mutex_lock(&mutex);
write_port();
pthread_mutex_unlock(&mutex);
pthread_exit(NULL);
}

void create_thread(void )
{
int temp;
memset(thread, 0, sizeof(thread));
if((temp = pthread_create(&thread[0], NULL,(void *)send_thread, NULL)) != 0)
printf("create send_thread failed!\n");
if((temp = pthread_create(&thread[1], NULL,(void *)recv_thread, NULL)) != 0)
printf("create recev_thread failed!\n");

}

void wait_thread(void )
{
if(thread[0] !=0)
{
pthread_join(thread[0],NULL);
printf("send_thread end\n");
}
if(thread[1] !=0)
{
pthread_join(thread[1],NULL);
printf("recev_thread end\n");
}
}

int main(void )
{
int i;
if((fd=open_port(fd,1))<0){
perror("open_port error");
}
if((i=set_port(fd,9600,8,'N',1))<0){
perror("set_opt error");
}
/*用默认属性初始化互斥锁*/
pthread_mutex_init(&mutex,NULL);
int num = 100;
while (num)
{
create_thread();
wait_thread();
num--;
}
pthread_mutex_destroy(&mutex);
close(fd);
return 0;
}