User Exits › Using Communication Words in Exit Routines › Passing the Parameter List to All Routines

Passing the Parameter List to All Routines

All routines for CA MIM are invoked through a standard parameter list, pointed to by register 1. The offset values are:

+0

Contains the address of the routine-specific parameter list.

+4

Contains the address of the routine-specific communication word. (The initial contents are 0.)

When CA MIM is stopped, VM automatically releases all storage within the CA MIM service machine. Therefore, if the routine-specific communication word points to storage within the CA MIM service machine, the address is invalid for the initialization call to the routine when you restart CA MIM.

+8

Contains the fullword of flags that are used to pass status information to the routine.

Whenever a routine is loaded, an initialization call is made to the module. For this call, +0 of the parameter list is set to 0 and the first byte of the status flag is set to X'80'.

+C

Contains the address of the global communication word, which is shared by all routines. The contents, which are set by the MIMINIXT exit routine, are passed unchanged for all subsequent calls to a routine.

On entry, +C into the common parameter list is either zero or the value from when CA MIM was last stopped. The value that is returned at +C into the common parameter list is stored and passed to all later invocations of any other routine.

Note: For information about a specific exit routine, see the appropriate CA MIM component Programming Guide.