Exit identification and deletion is performed through a function code that indicates whether the input exit address should be added to or deleted from the POST exit address queue for the current address space. A function code of 4 indicates an exit creation request, while 8 indicates an exit deletion request. Details of this interface are in “Branch Entry to the POST Service Routine”.
A 24-bit caller of the POST-exit-delete function can only delete an exit below 16 megabytes; a 31-bit caller must pass a valid 31-bit address and can delete an exit above or below 16 megabytes.
The process that establishes a POST exit is responsible for deleting that exit before its normal or abnormal termination.