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HEAPZONES z/OS Language Environment Programming Reference SA38-0683-00 |
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Derivation: HEAP check ZONES The HEAPZONES runtime option is used to turn on overlay toleration and checking for user heaps. When activated, the runtime option affects any obtained storage that can be controlled by the HEAP or HEAP64 runtime options. HEAPZONES also affects storage obtained from a heap pool. A heap check zone is an additional piece of storage that is appended to an allocated element during a storage request. The size of the check zone depends on the size31 and size64 suboptions of HEAPZONES. The check zone can be examined for overlays when the heap element is freed. The default value for non-CICS applications is HEAPZONES(0,ABEND,0,ABEND). The default value for CICS® applications is HEAPZONES(0,ABEND,0,ABEND). The default value for AMODE 64 applications is HEAPZONES(0,ABEND,0,ABEND). Syntax .-ABEND-. .-ABEND-. >>-HEAPZones--(--+--------+--,--+-------+--,--+---------+--,--+-------+--)->< '-size31-' +-QUIET-+ '-size-64-' +-QUIET-+ +-MSG---+ +-MSG---+ '-TRACE-' '-TRACE-'
Usage notes
Performance considerationsUsing heap check zones can result in a performance degradation and significant additional storage usage. IBM recommends setting the size of a heap check zone to the smallest amount feasible by the application. |
Copyright IBM Corporation 1990, 2014
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