Resource Management

IBM® recommends that a program running under the job step task, rather than under a subtask of the job step task, acquire and release these cross memory resources: AXs, EAXs, LXs, authority tables, and entry tables. Likewise, the same program should load the PC routines.

During normal termination, the program that obtained cross memory resources should release those resources. If this is not done, however, MVS™ releases these resources during termination of the job step task.

When the job step task of an address space terminates, MVS eliminates any cross memory connections between the terminating address space and other address spaces. After these connections are eliminated:

Programs executing in other address spaces cannot access the terminating address space through a PT, SSAR, or PC instruction.
Programs executing in other address spaces cannot use ARs to access the terminating address space.
Subsequent job steps can execute but cannot obtain cross memory resources. If such a job step issues an LXRES, AXRES, or ETCRE macro, the system returns an X'052' abend code.