#include <pthread.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#define NUM_THREADS	2
// gcc -lpthread  -o thread-example thread-example.c 
int global = 6;
char buf[] = "a write to standard output\n";
int var = 88;

void *thread( void *thread_id )
{
        int *id_ptr, taskid;
        id_ptr = ( int * ) thread_id;
        taskid = *id_ptr;
        if ( taskid == 0 ) { ++global; ++var; }
        else sleep( 2 );
        printf( "pid = %d, taskid = %d, global = %d, var = %d\n",
                getpid(), taskid, global, var );
	pthread_exit( NULL );
}

int main( void )
{
        pthread_t threads[ NUM_THREADS ];
        int t, rc;
        if ( write( STDOUT_FILENO, buf, sizeof (buf) - 1 )
             != sizeof( buf ) - 1 ) {
                fprintf( stderr, "write error" );
                exit( 1 );
        }
        printf( "before pthread_create()\n" );
	for ( t = 0; t < NUM_THREADS; ++t ) {
                rc = pthread_create( &threads[t], NULL, thread,
				     ( void * ) &t );
		if ( rc ) {
			printf
                        ( "ERROR; return code from pthread_create() is %d\n",
			      rc );
			exit( -1 );
		}
	}
        sleep( 3 );
        printf( "pid = %d, global = %d, var = %d\n",
                getpid(), global, var );
	pthread_exit( NULL );
}