ANYHEAP controls the allocation of library heap storage that is not restricted to a location below the 16-MB line.

The ANYHEAP option is always in effect. If you do not specify ANYHEAP or if you specify ANYHEAP(0), Language Environment allocates the value of 16K when a call is made to get heap storage.

Non-CICS default

ANYHEAP=((16K,8K,ANYWHERE,FREE),OVR)

CICS® default

ANYHEAP=((4K,4080,ANYWHERE,FREE),OVR)

Syntax

                                                 .-ANYWHERE-.   
>>-ANYHEAP--=--(--(--init_size--,--incr_size--,--+-ANY------+--->
                                                 '-BELOW----'   

      .-FREE-.        .-OVR----.      
>--,--+-KEEP-+--)--,--+-NONOVR-+--)----------------------------><

init_size

Determines the minimum initial size of the anywhere heap storage. This value can be specified as n, nK, or nM bytes of storage. The actual amount of allocated storage is rounded up to the nearest multiple of 8 bytes.

incr_size

Determines the minimum size of any subsequent increment to the anywhere heap area, and is specified in n, nK, or nM bytes of storage. This value is rounded up to the nearest multiple of 8 bytes.

ANYWHERE|ANY

Specifies that heap storage can be allocated anywhere in storage. If there is no storage available above the line, storage is acquired below the 16-MB line.

The only valid abbreviation for ANYWHERE is ANY.

BELOW

Specifies that heap storage must be allocated below the 16-MB line in storage that is accessible to 24-bit addressing.

FREE

Specifies that storage allocated to ANYHEAP increments is released when the last of the storage is freed.

KEEP

Specifies that storage allocated to ANYHEAP increments is not released when the last of the storage is freed.

OVR

Specifies that the option can be overridden.

NONOVR

Specifies that the option cannot be overridden.

CICS considerations

Both the initial size and the increment size are rounded up to the nearest multiple of 8 bytes. If ANYHEAP(0) is specified, the initial HEAP is obtained on the first use and will be based on the increment size. The maximum initial and increment size for ANYHEAP under CICS is 1 gigabyte (1024 MB).

The default increment size under CICS is 4080 bytes, rather than 4096 bytes, to accommodate the 16-byte CICS storage check zone. Without this accommodation, an extra page of storage is allocated (only when the storage allocation is below the 16MB line).

Performance considerations

The ANYHEAP option improves performance when you specify values that minimize the number of times the operating system allocates storage. The RPTSTG runtime generates a report of the storage the application uses while running; you can use the report numbers to help determine what values to specify.

For more information

• See z/OS Language Environment Programming Guide for more information about Language Environment heap storage.
• See RPTSTG for more information about the RPTSTG runtime.
• For more information about heap storage tuning with storage report numbers, see z/OS Language Environment Programming Guide.