Miscellaneous Routines


pthread_equal(thread1, thread2)

pthread_self returns the unique, system assigned thread ID of the calling thread.

pthread_equal compares two thread IDs. If the two IDs are different 0 is returned, otherwise a non-zero value is returned.

Note that for both of these routines, the thread identifier objects are opaque and can not be easily inspected. Because thread IDs are opaque objects, the C language equivalence operator (==) should not be used to compare two thread IDs against each other, or to compare a single thread ID against another value.

pthread_once(once_control, init_routine)

pthread_once executes the init_routine exactly once in a process. The first call to this routine by any thread in the process executes the given init_routine, without parameters. Any subsequent calls will have no effect.

The init_routine routine is typically an initialization routine.

The once_control parameter is a synchronization control structure that requires initialization prior to calling pthread_once. For example:

pthread_once_t once_control = PTHREAD_ONCE_INIT;`