Control flow

Follow the high-level control flow of a typical BTS business transaction.

The high-level control flow of a typical BTS business transaction is as follows:
  1. A CICS transaction makes an initial request to start a process.
  2. CICS initiates the appropriate root activity.
  3. The root activity program, using the BTS API, creates a child activity—or several child activities. It provides the child activity with some input data (by placing the data in a data-container associated with the child), and requests CICS to start the child activity.

    If, as is often the case, the child activity is to run asynchronously with the root activity, the root activity program returns and becomes dormant.

  4. The root activity is invoked again when one of its child activities completes. It determines which event caused it to be invoked again - that is, the completion of the activity that it started earlier. It retrieves, from the output data-containers of the completed activity, any return data that the completed activity has placed there.
  5. Steps 3 and 4 are repeated until all the child activities that make up the business transaction have completed.
  6. CICS terminates the root activity.

    If the business transaction has completed normally, the process is no longer known to CICS.