APPCCMD CONTROL=CHECK

Purpose

This macroinstruction waits for completion of an asynchronous macroinstruction request and marks the RPL and RPL extension used in the request as inactive upon completion.

Usage

When asynchronous handling is specified for an RPL-based request, the application program receives control when the request has been accepted by VTAM® and the requested operation has been scheduled. An APPCCMD CONTROL=CHECK macroinstruction must be issued for the RPL used for the request to determine when the macroinstruction completes and to get the return code information. APPCCMD CONTROL=CHECK cannot be issued for synchronous requests. In addition, APPCCMD CONTROL=CHECK cannot be issued for an RPL that specifies a non-APPCCMD request. This macroinstruction can be issued in cross-memory mode against an active asynchronous RPL request only when the RPL's ECB has been posted or the RPL exit has been scheduled.

When APPCCMD CONTROL=CHECK is executed for an RPL that specifies an ECB, the following actions occur:

If the operation being checked has not been completed, VTAM suspends the execution of the application program task under which the APPCCMD CONTROL=CHECK is issued until the operation is completed.
If the operation being checked has completed, VTAM returns control to the next sequential instruction after the APPCCMD CONTROL=CHECK macroinstruction.
The ECB (internal or external) is cleared before VTAM returns control to the application program. (The ECB must be cleared before an RPL-based macroinstruction is issued.)
Note: The ECB specified in an asynchronous APPCCMD macroinstruction must not be cleared between the time it is issued and the corresponding APPCCMD CONTROL=CHECK is issued. If the ECB is cleared during this interval, control cannot be returned to the application program after the APPCCMD CONTROL=CHECK is issued.
The RPL being checked is marked available for reuse by another APPCCMD macroinstruction. (APPCCMD CONTROL=CHECK is the only way this can be done for asynchronous APPCCMD requests.)

When APPCCMD CONTROL=CHECK is executed in an RPL exit routine for the associated RPL, the following actions occur:

VTAM marks the RPL being checked as available for reuse by another APPCCMD macroinstruction.
If the operation being checked has completed, VTAM returns control to the next sequential instruction after the APPCCMD CONTROL=CHECK.

Context

Input states are not applicable to this macroinstruction.

This macroinstruction is not allowed for conversations pending deallocation for persistent LU-LU sessions.

Syntax


                                                                              (1)          
>>-+---------+--APPCCMD-- --CONTROL--=--CHECK--,--RPL--=--+-rpl_address_field----------+-><
   '- --name-'                                            '-(--rpl_address_register--)-'

Notes:

See Coding default values for information on coding operands on the RPL or APPCCMD macroinstruction.

Input parameters

RPL=rpl_address_field
RPL=(rpl_address_register): Specifies the address of the request parameter list that contains information to be used during the processing of the APPCCMD macroinstruction.

RPL and RPL extension fields modified by macroinstruction

After the APPCCMD CONTROL=CHECK macroinstruction has completed, the completion information returned is for the macroinstruction being checked. Refer to the description of the particular APPCCMD being checked for a list of the parameters that are returned to the application program.