event-id

    OpenVMS usage identifier
    type          longword (unsigned)
    access        read only
    mechanism     by reference
    Identifier of the event. The event-id argument is the address of
    an unsigned longword containing the identifier.

    Event-id is returned by PPL$CREATE_EVENT.

 event-param

    OpenVMS usage user_arg
    type          longword (unsigned)
    access        read only
    mechanism     by value
    An arbitrary value to be passed to all requests processed for
    the event as a result of the trigger, or, if there are no queued
    event notification requests for this event, to the first caller
    to enable event notification. The event-param argument is the
    address of an unsigned longword containing this value. The value
    of event-param is received by the output argument of PPL$AWAIT_
    EVENT.

    If a participant enables delivery of an AST by calling
    PPL$ENABLE_EVENT_AST, this argument appears in the second
    longword of the vector specified by the astprm argument. If a
    participant enables delivery of a signal by calling PPL$ENABLE_
    EVENT_SIGNAL, this argument appears as the third longword in the
    signal vector when the condition is raised.

 flags

    OpenVMS usage mask_longword
    type          longword (unsigned)
    access        read only
    mechanism     by reference
    Specifies options for triggering an event. The flags argument is
    the address of a longword bit mask containing the flag. The valid
    value for flags is as follows:

    PPL$M_NOTIFY_ONE   Processes exactly one enabled event
                       notification. By default, all pending actions
                       are processed when the event state becomes
                       occurred.