Introduction to the Batch adapters

The Batch/TSO adapters are the interface between z/OS application programs running under JES, TSO, or UNIX System Services and WebSphere MQ. They enable z/OS application programs to use the MQI.

The adapters provide access to WebSphere MQ resources for programs running in the following modes or states:

• Task (TCB) mode

• Problem or supervisor state

• Non-cross-memory mode

• Non-access register mode

Connections between application programs and WebSphere MQ are at the task level. The adapters provide a connection thread from an application task control block (TCB) to WebSphere MQ.

The Batch/TSO adapter supports a single-phase commit protocol for changes made to resources owned by WebSphere MQ. It does not support multi-phase commit protocols. The RRS adapter enables WebSphere MQ applications to participate in two-phase commit protocols with other RRS-enabled products, coordinated by z/OS Resource Recovery Services (RRS).

The adapters use the z/OS STIMERM service to schedule an asynchronous event every second. This event runs an interrupt request block (IRB) that does not involve any waiting by the batch application's task. This IRB checks to see if the WebSphere MQ termination ECB has been posted. If the termination ECB has been posted, the IRB posts any application ECBs that are waiting on an event in WebSphere MQ (for example, a signal or a wait).