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Calling DFSMShsm Installation Exits z/OS DFSMS Installation Exits SC23-6850-01 |
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The DFSMShsm installation exits must be accessible by the LOAD macro and must communicate with the standard MVS linkage for registers. Registers on Entry to DFSMShsm Installation Exits and Registers on Return from DFSMShsm Installation Exits describe standard MVS linkage with which DFSMShsm complies. The exits must save and restore registers. DFSMShsm does not place return codes in the registers; it includes them as parameters in the parameter list for exits that provide return codes. An installation exit cannot issue the DFSMShsm supervisor call instruction (SVC). DFSMShsm calls each of its exits in the addressing mode in which they were link edited (either 24-bit mode or 31-bit mode), except for the ARCTVEXT exit, which must be in 24-bit mode. Because DFSMShsm responds differently to abends that occur for different exits, the actions DFSMShsm takes are described for each exit. Generally, when an exit abends, DFSMShsm issues a HOLD on the function, writes a message, and does not call the exit again until either a DFSMShsm RELEASE command releases the function or a SETSYS command requests the function. The exit parameter list contains pointers to the information described in the discussion of each individual exit. It points to copies of the information unless specifically stated otherwise. The exits are ESTAE protected. They are not subject to TRAP commands. If an exit abends and you require a dump for problem determination, see the z/OS DFSMShsm Diagnosis. Table 1 lists the hex values for exits that do selective processing based on the device type DFSMShsm is processing.
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Copyright IBM Corporation 1990, 2014
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