HEAP (non-CICS)
HEAP controls the allocation of the initial heap, additional heaps created with the CEECRHP callable service, and specifies how that storage is managed.
When Fortran is the only selected language, values for HEAP will be changed to (4K,4K,ANY,KEEP,8K,4K) .
HEAP has the following suboptions :
- initial size : the minimum size of the initial heap storage, rounded
to the nearest 8 bytes, maximum size of 16 MB with ANYWHERE or 1 MB with BELOW
- initial size units : the units that initial size is specified in (K, M)
- initial size 24 : the minimum size of the initial heap storage obtained below the 16
MB line for applications running with ALL31(OFF) and ANYWHERE specified in the HEAP option, maximum size of 1 MB with BELOW (not used with ANYWHERE)
- initial size 24 units : the units that initial size 24 is specified in (K, M)
- increment size : the minimum initial size of any subsequent
increment to heap storage, maximum size of 16 MB with ANYWHERE or 1 MB with BELOW
- increment size units : the units that
increment size is specified in (K, M)
- increment size 24 : the minimum initial size of any subsequent increment to heap storage obtained below the 16 MB line for applications running with ALL31(OFF) and ANYWHERE
maximum size of 1 MB with BELOW (not used with ANYWHERE)
- increment size 24 units : the units that increment size 24 is specified in
(K, M)
- ANYHWERE or BELOW :
ANYWHERE allows heap storage to be allocated anywhere in storage. If there is
no storage available above the line, storage is acquired below the line.
BELOW ensures that heap storage must be allocated below the 16 MB line in storage that is
accessible to 24-bit addressing.
Notes :
z/OS UNIX System Services consideration : The HEAP option applies to the
enclave. Heap storage is managed at the
thread level using pthread_key_create, phtread_setspecific, and
pthread_getspecific.