PTHREAD_JOIN32(),  PTHREAD_JOIN64()

       The pthread_join32() and pthread_join64() forms are only
       valid in 64-bit pointer environments for OpenVMS Alpha.
       Ensure that your compiler provides 64-bit support before you
       use pthread_join64().

    Causes the calling thread to wait for the termination of a
    specified thread.

1  –  C Binding

    #include <pthread.h>

    int
    pthread_join (
             pthread_t   thread,
             void   **value_ptr);

2  –  Arguments

 thread

    Thread whose termination is awaited by the calling routine.

 value_ptr

    Return value of the terminating thread (when that thread either
    calls pthread_exit() or returns from its start routine).

3  –  Description

    This routine suspends execution of the calling thread until the
    specified target thread thread terminates.

    On return from a successful pthread_join() call with a non-
    NULL value_ptr argument, the value passed to pthread_exit()
    is returned in the location referenced by value_ptr, and the
    terminating thread is detached.

    If more than one thread attempts to join with the same thread,
    the results are unpredictable.

    A call to pthread_join() returns after the target thread
    terminates. The pthread_join() routine is a deferred cancelation
    point; the target thread will not be detached if the thread
    blocked in pthread_join() is canceled.

    If a thread calls this routine and specifies its own pthread_t, a
    deadlock can result.

    The pthread_join() (or pthread_detach())  routine should
    eventually be called for every thread that is created with the
    detachstate attribute of its thread object set to PTHREAD_CREATE_
    JOINABLE, so that storage associated with the thread can be
    reclaimed.

                                   NOTE

       For OpenVMS Alpha systems:
       The pthread_join() routine is defined to pthread_join64()
       if you compile using /pointer_size=long. If you do not
       specify /pointer_size, or if you specify /pointer_
       size=short, then pthread_join() is defined to be pthread_
       join32(). You can call pthread_join32() or pthread_join64()
       instead of pthread_join(). The pthread_join32() form
       returns a 32-bit void * value in the address to which
       value_ptr points. The pthread_join64() form returns a 64-
       bit void * value. You can call either, or you can call
       pthread_join(). Note that if you call pthread_join32() and
       the thread with which you join returns a 64-bit value, the
       high 32 bits of which are not 0 (zero), the Threads Library
       discards those high bits with no warning.

4  –  Return Values

    If an error condition occurs, this routine returns an integer
    indicating the type of error. Possible return values are as
    follows:

    Return      Description

    0           Successful completion.
    [EINVAL]    The value specified by thread does not refer to a
                joinable thread.
    [ESRCH]     The value specified by thread does not refer to an
                existing thread ID.
    [EDEADLK]   A deadlock was detected, or thread specifies the
                calling thread.

5  –  Associated Routines

       pthread_cancel()
       pthread_create()
       pthread_detach()
       pthread_exit()