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DYNALLOC — Dynamic allocation z/OS MVS Programming: Authorized Assembler Services Reference ALE-DYN SA23-1372-00 |
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DescriptionUse the DYNALLOC macro to invoke dynamic allocation functions. Before attempting to use this macro, you must read the chapters “Dynamic Allocation” and “Requesting Dynamic Allocation Functions” in z/OS MVS Programming: Authorized Assembler Services Guide, for complete information on DYNALLOC. EnvironmentRequirements for the caller are:
Programming requirementsThe calling program must include the following mapping macros to
construct the SVC 99 parameter list:
See z/OS MVS Programming: Authorized Assembler Services Guide for details on constructing the parameter list. RestrictionsSee z/OS MVS Programming: Authorized Assembler Services Guide for programming restrictions and limitations. Register informationOn entry to the macro, general purpose register 1 must contain the address of a pointer to the SVC 99 parameter list structure. See z/OS MVS Programming: Authorized Assembler Services Guide for a detailed description of the parameter list. After the caller issues the macro, the system might use some registers as work registers or might change the contents of some registers. When the system returns control to the caller, the contents of these registers are not the same as they were before the caller issued the macro. Therefore, if the caller depends on these registers containing the same value before and after issuing the macro, the caller must save these registers before issuing the macro and restore them after the system returns control. When control is returned to the calling program the GPRs contain:
Performance implicationsThere are no performance implications when the restrictions and limitations are all met. SyntaxThe DYNALLOC macro is written as follows:
ParametersThere are no parameters for DYNALLOC. Return and reason codesWhen control returns from DYNALLOC, GPR 15 contains a return code. The return codes and associated reason codes are described in z/OS MVS Programming: Authorized Assembler Services Guide. |
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