Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (P)
Guardian Procedure Calls Reference Manual—522629-013
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PROCESS_LAUNCH_ Procedure
Z^HEAP^MAX
for native processes only, specifies the maximum size, in bytes, of the process
heap. Note that the sum of the size of the heap and the size of global data cannot
exceed 1.1 gigabytes (GB).
The default value of 0D indicates that the heap can grow to the default value of 1.1
gigabytes (GB) less the size of the globals. The initial heap size of a process is
zero bytes. For most processes, the default value is adequate.
It is recommended that the value of
Z^HEAP^MAX parameter should be set to zero.
The developer then sets an appropriate value for
Z^HEAP^MAX in the object file of
the application depending on the kind of application, the maximum memory
required and the system configuration.
Z^HEAP^MAX then defaults to the value
stored in the object file of the application to be launched.
An outline of existing limitations:
Native C and C++ programs can have up to 1.1 GB of heap. CISC objects can
have up to 127.5 megabytes (MB) of heap. However, other demands for memory
space can deplete the amount of memory available for heap.
Z^SPACE^GUARANTEE
specifies the minimum size, in bytes, of the amount of space that the process
reserves with the Kernel-Managed Swap Facility for swapping. For more
information on this facility, refer to the
Kernel-Managed Swap Facility (KMSF)
Manual. The value provided is rounded up to a page size boundary of the
processor. If the requested amount of space is not available,
PROCESS_LAUNCH_ returns error 55.
When the default value of 0D is used, the amount of space reserved is determined
by the value specified in the object file for a native process or by the operating
system for a TNS or accelerated process.
Z^CREATE^OPTIONS
provides information about the environment of the new process.
The following table summarizes the possible values for Z^CREATE^OPTIONS.
TAL literals are defined in the ZSYSTAL file. Literals in the
zsysc file, for C
programs, are the same as those for TAL except that they contain the underscore
(_) character instead of the circumflex (^) character.