OPERATOR-SLIP subcommand

Use the SLIP subcommand to control SLIP (serviceability level indication processing), a diagnostic aid designed to intercept or trap certain system events. You can indicate what kinds of events you want trapped and what the system should do when these events occur.

The kinds of events you can intercept are:

Program event recording (PER) events
- Instruction fetch PER interruption
- Successful branch PER interruption
- Storage alteration PER interruption
Error events
- Paging error
- Dynamic address translation error
- Machine check associated software error
- Address space termination error
- SVC 13 issued by a task
- SVC error
- Program check interruption
- Restart interruption

When one of these events occurs, you can take one of the following actions:

request and tailor an SVC dump specifically to your needs
cause SLIP to write a GTF trace record
suppress dumps (for error events only)
ignore the event
cause the recovery routines of the interrupted process to get control
cause SLIP to write a system trace table record
cause SLIP to write a SYS1.LOGREC record

The PER and error events you can trap are general, and you probably do not want to take one of those actions each time such an event occurs. To narrow the scope of SLIP processing, qualify the event by specifying exactly what state the system must be in when the error or PER event happens for the action to occur. SLIP checks each specified condition to see if it corresponds to the system condition at the time of the error or PER interruption. The conditions you specify serve as filters to screen out those events you are not interested in. When conditions you specify are the same as those in the system, a match occurs. When conditions you specify are not the same as those in the system, a no-match occurs. Only when a match occurs will SLIP take the specified action. Among the conditions you can specify are:

the type of error the system is processing
the system mode at the time of the error or PER interruption
a user or system completion code associated with the error
the name of a job or job step program that must be in control at the time of the error or PER interruption
the module name or address range where the error or PER interruption must occur
the address space that must be in control at the time of the error or PER interruption
the contents of specific storage locations and/or registers at the time of the error or interruption

If you do not specify a particular condition, then SLIP makes no checks for that condition.

When you define more than one SLIP trap, SLIP first examines the last defined trap. If it does not find a match condition, it proceeds to check the previously defined trap.

Note that the OPER SLIP command:

Is limited to 126 characters.
Cannot use any TSO/E I/O services including the stack.

There are three types of SLIP subcommands:

SLIP SET subcommand defines SLIP traps.
SLIP MOD subcommand enables or disables previously defined SLIP traps.
SLIP DEL subcommand deletes previously defined SLIP traps.

For more information about designing an effective SLIP trap, see z/OS Problem Management.