Implementing the CICS wait list

The CICS Wait List can be implemented by means of a customer modifiable data set, pointed to by the Installation Options Data Set (WAITLIST parameter). The default WAITLIST includes all services which can complete asynchronously (for example, those services which perform I/O to a key data set and those services which are routed to a cryptographic processor). If the option is not specified, the default CICS Wait List will be utilized by ICSF when a CICS application invokes an ICSF callable service. If WAITLIST is specified, the data set specified by this parameter will be used to determine the names of the services to be placed on the CICS Wait List. A sample data set is provided by ICSF via member CSFWTL01 of SYS1.SAMPLIB. The sample data set contains the same entries as the default ICSF CICS Wait List -- for example, the data set contains the names of all ICSF callable services which, by default, will be driven through the CICS TRUE.

The WAITLIST option should be added to the Installation Options data set under these conditions.

Non-CICS customers will not specify a WAITLIST keyword.
CICS customers who want to use the default CICS Wait List shipped with ICSF will not specify a WAITLIST keyword. If you have any existing CICS applications which invoke any of the ICSF services in the Wait List, then these applications must be re-linked with the current ICSF stubs.
CICS customers who do not want to make use of CICS TRUE must either not enable the TRUE or specify a WAITLIST keyword and point to an empty wait list data set or you can specify WAITLIST(DUMMY) in the Installation Options data set.
CICS customers who wish to modify the ICSF default CICS Wait List should modify the sample Wait List data set supplied in member CSFWTL01 of SYS1.SAMPLIB. The WAITLIST keyword in the Installation Options Data Set should be set to point to this data set. If you have any existing CICS applications which invoke any of the ICSF services in the Wait List, then these applications must be re-linked with the current ICSF stubs.

If you already have the CICS-ICSF Attachment facility installed, there are a number of callable services which may potentially be routed to a coprocessor or may perform other asynchronous processing. If you have a modified CICS Wait List, you should ensure that the wait list data set includes all such services, and any CICS applications which invoke any of these services are re-linked with the current ICSF stubs. As a model, you can use the default CICS Wait List that is shipped with ICSF which includes all services which have an asynchronous interface to ICSF or you can use a sample Wait List data set that is also shipped with ICSF. The sample CICS Wait List data set is contained in member CSFWTL01 of SYS1.SAMPLIB. The sample data set contains the same entries as the default ICSF CICS Wait List. If you have an application which invokes a UDX while running under CICS, then the name of the UDX generic service should be added to the CICS Wait List.

If you use a CICS Wait List data set, you need to identify the data set to ICSF through the WAITLIST(data_set_name) option in the ICSF Installation Options data set. The data set can be a member of a PARMLIB, a member of a partitioned data set, or a sequential data set. The data set should be allocated on a permanently resident volume and should adhere to:

The format of each record in the data set must be fixed length or fixed block length.
A physical line in the data set must be a LRECL of 80 characters long. The system ignores any characters in positions 73 to 80 of the line.
You can delimit comments by "/*" and "*/" and include them anywhere in the text. A comment cannot span physical records.
Only one service may be specified on a logical line.

Note: You can use the WAITLIST(DUMMY) parameter to specify a null CICS Wait List data set, or you can disable the CICS TRUE if you do not want to utilize the CICS TRUE. See Parameters in the installation options data set for additional information.