The Remove Entry from Head of Queue routine removes an entry
    from the head of the specified self-relative longword interlocked
    queue. LIB$REMQHI makes the REMQHI instruction available as a
    callable routine.

    Format

      LIB$REMQHI  header ,remque-address [,retry-count]

1  –  Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

2  –  Arguments

 header

    OpenVMS usage:quadword_signed
    type:         quadword integer (signed)
    access:       modify
    mechanism:    by reference

    Queue header specifying the queue from which entry will be
    removed. The header argument contains the address of this signed
    aligned quadword integer. The header argument must be initialized
    to zero before first use of the queue; zero means an empty queue.

    On Alpha and I64 systems, the header argument must contain a
    32-bit address. A 64-bit address results in an illegal operand
    exception.

 remque-address

    OpenVMS usage:address
    type:         longword (unsigned)
    access:       write only
    mechanism:    by reference

    Address of the removed entry. The remque-address argument is the
    address of an unsigned longword that contains this address. If
    the queue was empty, remque-address is set to the address of the
    header.

    On Alpha and I64 systems, the remque-address argument must
    contain a 32-bit address. A 64-bit address results in an illegal
    operand exception.

 retry-count

    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    The number of times the operation is to be retried in case
    of secondary-interlock failure of the queue instruction in a
    processor-shared memory application. The retry-count argument is
    the address of a longword that contains the retry count value. A
    value of 1 causes no retries. The default value is 10.