Thread: Scheduling Policy

Hi,

I am trying to learn pthreads and pthreads attributes... I wrote a simple program which creates 2 threads... 1 prints world and another prints hello... I have set priority of the thread which prints hello higher than the other so it should print hello world.. but some how it isn't doing so...

Here's the code...

Code:

#include <stdio.h>
#include <pthread.h>
#include <sched.h>

pthread_mutex_t mutex1;

char *message1 = "Hello";
char *message2 = "World";

void print_Hello( void );
void print_World( void );

int main()
{
	pthread_t thread1, thread2;
	pthread_attr_t atri1,atri2;
	
	int priority_high=500, priority_low=10;
	int status=0;
	int t = 25;
	struct sched_param para1;
	struct sched_param para2;
	para1.sched_priority = priority_high;
	para2.sched_priority = priority_low;
	status = pthread_mutex_init(&mutex1,NULL);
        if(status!=0)
        {
                printf("\nMUTEX init failed !\n");
                return 0;
        }

	status = pthread_attr_init(&atri1);
	if(status!=0)
	{
		printf("\nAttribute init failed !\n");
		return 0;
	}
	status = pthread_attr_init(&atri2);
	if(status!=0)
	{
                printf("\nAttribute init failed !\n");
                return 0;
        }
	status = pthread_attr_setschedpolicy(&atri1, SCHED_RR);
	if(status!=0)
        {
                printf("\nSched policy init failed 1!\n");
                return 0;
        }
	status = pthread_attr_setschedpolicy(&atri2, SCHED_RR);
        if(status!=0)
        {
                printf("\nSched policy init failed 2!\n");
                return 0;
        }

	status = pthread_attr_setschedparam(&atri1, &para1);
	if(status!=0)
        {
                printf("\nCould not set Priority : 1 !\n");
                return 0;
        }
	status = pthread_attr_setschedparam(&atri2, &para2);
        if(status!=0)
        {
                printf("\nCould not set priority : 2!\n");
                return 0;
        } 
	while(--t>0)
	{       status=pthread_create( &thread1, &atri2,(void*)&print_World, NULL);
		if(status!=0)
			printf("\nThread 1 Could not be created");
		status=	pthread_create(&thread2, &atri1,(void*)&print_Hello, NULL);
		if(status!=0)
			printf("\nThread 2 Could not be created");
	}
	return 0;
}
void print_Hello( void )
{

//	while(1)
//	{
		pthread_mutex_lock(&mutex1);
		printf("%s ", message1); 
		pthread_mutex_unlock(&mutex1);

//	}
}
void print_World( void )
{

//	while(1)
//	{ 
       		 pthread_mutex_lock(&mutex1);
		 printf("%s ", message2);
		 pthread_mutex_unlock(&mutex1);

//	}
}

I tried changing scheduling policies, adding / removing mutex but still it keep on printing World Hello World Hello...

So, can anybody suggest what am I doing wrong?

Thanks,
Edesign