Building a Mailbox (IXZXIXMB Macro)

Any JES dispatchable unit (JDU) that intends to receive messages must build a mailbox. A mailbox holds messages that have been sent to a JDU but have not yet been processed by the JDU. A mailbox is simply a logical queue of ordered messages that is maintained by JES XCF. When a JDU retrieves and acknowledges a message, JES XCF removes that message from the mailbox.

When building a mailbox, you must identify a POST exit routine, which you previously coded, to receive control each time JES XCF places a message in the mailbox.

To build a mailbox, issue the IXZXIXMB macro. When you issue this macro, you must:

Provide the group token. This can either be the JES-defined group token that was obtained from the specific JES data area as noted in Retrieving the JES XCF Group Token, or your installation attach-defined group token that you obtained from JES XCF on return from the IXZXIXAT call.
Provide the address of an installation exit routine that receives control when JES XCF places a message in the mailbox. (This routine is hereafter referred to as the POST exit routine.)
Provide a pointer to data that the POST exit routine needs to access when it receives control.
Provide the name that you want assigned to the mailbox.

You must ensure that programs that issue macros that reference a mailbox have access to the mailbox name. The following macros reference mailboxes:

IXZXIXMC (mailbox clear)
IXZXIXMD (mailbox delete)
IXZXIXRM (receive message)
IXZXIXSM (send message).