#define _REENTRANT
#include <stdio.h>
#include <thread.h>

/* Function prototypes for thread routines */
void *my_sub(void *);

thread_t thr_a, thr_b, thr_c;
mutex_t my_mutex;

void main()
{
	thread_t main_thr;
	int flag;


	main_thr = thr_self();
	fprintf(stderr,"Main thread = %d\n", main_thr); 

	if (thr_create(NULL, 0, my_sub, NULL, THR_SUSPENDED, &thr_b))
	{
		fprintf(stderr,"Can't create thr_b\n");
		exit(1);
	}

	if (thr_create(NULL, 0, my_sub, NULL, THR_SUSPENDED, &thr_a))
	{
		fprintf(stderr,"Can't create thr_a\n");
		exit(1);
	}

	if (thr_create(NULL, 0, my_sub, NULL, THR_SUSPENDED, &thr_c))
	{
		fprintf(stderr,"Can't create thr_c\n");
		exit(1);
	}

	fprintf(stderr,"Main Created threads A:%d B:%d C:%d\n",
		 thr_a, thr_b, thr_c); 

	mutex_init(&my_mutex,USYNC_THREAD,NULL);

	thr_continue(thr_a);
	thr_continue(thr_b);
	thr_continue(thr_c);

	fprintf(stderr,"Main Thread exiting...\n"); 
	thr_exit((void *)main_thr);
}


void *my_sub(void *arg)
{
	int which_thread;
	mutex_lock(&my_mutex);

	which_thread = thr_self();
	fprintf(stderr,"Thread %d has locked the mutex.\n",which_thread);

	mutex_unlock(&my_mutex);

	fprintf(stderr,"Thread %d is exiting.\n",which_thread);

	thr_exit((void*)0);


}