/*******************************************************************
This is a sample threaded program in C. The main thread creates
4 threads. Each thread simply prints out a message before exiting.
Notice that I have set the thread attributes to joinable.
Compilation: gcc threads.c -o threads -Wall -lpthread
*******************************************************************/

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

#define NUM_THREADS 4

void * thread_function (void *arg)
{
	int id = *((int *)arg);
	printf( "Hello from thread %d!\n", id );
	return NULL;
}


int main()
{
	int i, tmp;
	int arg[NUM_THREADS] = {0,1,2,3};
	pthread_t thread[NUM_THREADS];
	pthread_attr_t attr;

	/* initialize and set the thread attributes */
	pthread_attr_init( &attr );
	pthread_attr_setdetachstate( &attr, PTHREAD_CREATE_JOINABLE );


	/* creating threads */
	for ( i=0; i<NUM_THREADS; i++ ) {
		tmp = pthread_create( &thread[i], &attr, thread_function, (void *)&arg[i] );
		if (tmp != 0) {
			fprintf(stderr,"Creating thread %d failed!",i);
			return 1;
		}
	}

	/* joining threads (== waiting for them to exit) */
	for ( i=0; i<NUM_THREADS; i++ ) {
		tmp = pthread_join( thread[i], NULL );
		if ( tmp != 0 ) {
			fprintf(stderr,"Joing thread %d failed!",i);
			return 1;
		}
	}

	return 0;
}