I wam working on the operating systems and want guidance for its concepts

Synchronizing Threads with POSIX Semaphores and Mutex Posix semaphores are easy to use sem_init, sem_wait, sem_post, sem_getvalue, sem_destroy The program wrongcount.c creates two new threads, both of which increment a global variable called COUNT exactly ITERAT, with ITERAT = 1,000,000. But the program produces unexpected results.