IWM4SSM – WLM Server Select Secondary Service

The IWM4SSM service selects the next secondary work request from the queue associated with the caller's server task.

If there are no queued secondary work requests waiting for selection the calling task will be suspended, pending arrival of work to do. The caller cannot rely upon asynchronous exits receiving control while the task is suspended.

Secondary work requests are considered to be extensions of an original work request selected using IWM4SSL. The caller must invoke WLM services in the following sequence:

1. The caller invokes the IWM4SSL macro to select an initial work request. IWM4SSL returns a token identifying the server task. The caller is responsible for passing the server token to the queueing manager so that it can insert secondary work requests.
2. The caller invokes the IWM4STBG macro to establish an environment for processing the work request selected using IWM4SSL. This environment also covers all secondary work requests.
3. The caller invokes the IWM4SSM macro to select each secondary work request. The queueing manager is responsible for indicating the last secondary work request so that the server task knows when not to try to select another one.
4. After the last secondary work request has been processed, the caller invokes the IWM4STEN macro to remove the environment created by IWM4STBG.
5. The caller invokes IWM4SSL to select a new primary work request, and repeats the above flow.

In the above flow, IWM4SSL, IWM4STBG, IWM4SSM, and IWM4STEN must be invoked from the same task.