VMS Help POSIX Threads, TIS routines, tis_mutex_trylock  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Attempts to lock the specified mutex.

1 - C Binding

    #include <tis.h>

    int
    tis_mutex_trylock (
                pthread_mutex_t   *mutex);

2 - Arguments

 mutex

    Address of the mutex (passed by reference) to be locked.

3 - Description

    This routine attempts to lock the specified mutex mutex. When
    this routine is called, an attempt is made immediately to lock
    the mutex. If the mutex is successfully locked, zero (0) is
    returned.

    If the specified mutex is already locked when this routine
    is called, the caller does not wait for the mutex to become
    available. [EBUSY] is returned, and the thread does not wait
    to acquire the lock.

4 - Return Values

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

    Return      Description

    0           Successful completion.
    [EBUSY]     The mutex is already locked; therefore, it was not
                acquired.
    [EINVAL]    The value specified by mutex is not a valid mutex.

5 - Associated Routines

       tis_mutex_destroy()
       tis_mutex_init()
       tis_mutex_lock()
       tis_mutex_unlock()