Answer Happy

#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
pthread_t tid[2];
int counter;
pthread_mutex_t lock;
void* trythis(void* arg)
{
pthread_mutex_lock(&lock);
unsigned long i = 0;
counter += 1;
printf("\n Job %d has started\n", counter);
for (i = 0; i < (0xFFFFFFFF); i++)
; printf("\n
Job %d has finished\n", counter);
pthread_mutex_unlock(&lock);
return NULL;
}
int main(void)
{
int i = 0;
int error;
if (pthread_mutex_init(&lock, NULL) != 0) {
printf("\n mutex init has failed\n");
return 1;
}
while (i < 2) {
error = pthread_create(&(tid), NULL,
&trythis, NULL);
if (error != 0)
printf("\nThread can't be created :[%s]",
strerror(error));
i++;
}
pthread_join(tid[0], NULL);
pthread_join(tid[1], NULL);
pthread_mutex_destroy(&lock);
return 0;
}