Previous Topic: PUSH()Next Topic: QUEUES()


QUEUE()

This function adds records to the bottom of any stack belonging to any IMOD.

Restriction

QUEUE() can specify a stack external to an IMOD only when the target stack has been declared public for writing or for queuing.

Syntax

QUEUE([record],[stack],[owner],,[postoption])

Parameters

record

Record to be added to the stack. A zero-length record is added by default.

stack

Number of the stack to be referenced.

Default: If a local stack is referenced, the current stack (as set by the SWAPSTAK() function). Otherwise, the owning IMOD task sets the value using the PUBSTACK(DEFAULT) function.

owner

IMOD ID of the owner of the stack (for external reference). This value can be obtained from the variable imod_id in the owning IMOD task. It is also the value that the SPAWN() function returns.

Default: Current IMOD task.

postoption

Wait option, which determines whether the owning IMOD waits for a record to appear on an external stack. Specify one of these values:

POST

Any outstanding wait is satisfied; the default.

NOPOST

An outstanding wait is not satisfied.

ONLYPOST

Any outstanding wait is satisfied, but a record is not placed on the stack.

Note: If you are placing several records onto an external stack, we recommend that you specify we recommendOPOST for all but the final record. IMODs are time-sliced, and if the POST operation is performed before the final record is queued to the stack, the IMOD task owning the stack could be dispatched to process before the last QUEUE is completed.

Return Codes

101 - 105

ARG n MISSING OR INVALID

122

STACK NOT SPECIFIED AND NO DEFAULT

123

SPECIFIED STACK DOES NOT EXIST

125

SPECIFIED IMOD NOT FOUND

126

STACK WRITE FAILED

127

REQUESTED STACK DOES NOT EXIST

128

SPECIFIED IMOD/STACK NOT AUTHORIZED

Example

x = queue(rec)                /* A record is queued to the
                                 current stack */
x = queue(rec,2)              /* A record is queued to local
                                 stack 2 */
x = queue(rec,,453,,'post')   /* A record is queued to IMOD 453's
                                 default stack. Any outstanding
                                 wait will be marked complete. */