gtpi1m4m | System Installation Support Reference |
The selective activate message router exit, UELH, determines if an ECB is from an ECB origin enabled to use a selectively activated loadset. If it is, UELH copies the list of activation numbers associated with the ECB origin to a core area obtained using MALLOC. It then calls the CEL9 assembler program to set up the ECB field to point to the MALLOC area and update the EAT (ECB Activation Table) slots.
UELH is called by the message router package.
Input
Programming Considerations
The CE2ANL field has been added to the ECB. This field will contain the address of the Selective Activation Number List. Opzero initializes CE2ACN with the system's current activation number. UELH initializes CE2ANL based on the origin of the ECB.
Each entry in the CE2ANL list is a 4-byte activation number with the last entry having a F'0' value. The user exit should scan the selective activation index for the ECB origin, and if found, place the associated activation numbers in the list. The maximum number of activation numbers that can be associated with an ECB origin is limited by the size of an SWB (which is used when transferring the activation number list from parent to child ECB).
Notes:
The user exit must pass the address of the constructed activation number list to the CE2ANL update routine. IBM code updates CE2ANL because CE2ANL resides in protected page 2 of the ECB which should not be modified by user code.
IBM supplied code (CEL9) will increment the ECB count in the EAT slots associated with each activation number in the activation number list.
Return Values