queue_header

    OpenVMS usage address
    type          quadword (unsigned)
    access        read only
    mechanism     by value
    Address from which to start search.

 options

    OpenVMS usage mask_longword
    type          longword (unsigned)
    access        read only
    mechanism     by value
    The following table shows the flags that indicate the type of
    queue:

    Flag                        Meaning

    None                        Defaults to doubly-linked longword
                                queue
    SDA_OPT$M_QUEUE_BACKLINK    Validates the integrity of a doubly-
                                linked queue using the back links
                                instead of the forward links
    SDA_OPT$M_QUEUE_LISTQUEUE   Displays queue elements for debugging
    SDA_OPT$M_QUEUE_QUADLINK    Indicates a quadword queue
    SDA_OPT$M_QUEUE_SELF        Indicates a self-relative queue
    SDA_OPT$M_QUEUE_SINGLINK    Indicates a singly-linked queue