How Exception Messages Are Handled

When you or the system send an exception message, exception processing begins. This processing continues until the exception is handled, which is when the exception message is modified to indicate that it has been handled.

The system modifies the exception message to indicate that it has been handled when it calls an exception handler for an OPM call message queue. Your ILE HLL modifies the exception message before your exception handler is called for an ILE call message queue. As a result, HLL-specific error handling considers the exception message handled when your handler is called. If you do not use HLL-specific error handling, your ILE HLL can either handle the exception message or allow exception processing to continue. Refer to your ILE HLL reference manual to determine your HLL default actions for unhandled exception messages.

With additional capabilities defined for ILE, you can bypass language-specific error handling. These capabilities include direct monitor handlers and ILE condition handlers. When you use these capabilities, you are responsible for changing the exception message to indicate that the exception is handled. If you do not change the exception message, the system continues exception processing by attempting to locate another exception handler. The topic Types of Exception Handlers contains details about direct monitor handlers and ILE condition handlers. For information that explains how to change an exception message, see the Change Exception Message (QMHCHGEM) API in the API topic collection of the Programming category of the IBM® i Information Center.