SRBs in Enclaves

Enclave SRBs offer advantages over local and global SRBs in that they are preemptable, and can be run at a lower major dispatching priority than tasks in the same address space.

SRBs in enclaves work well for transactions having short durations, not issuing supervisor calls, and not otherwise requiring a task environment. SRBs have very little startup overhead compared to tasks. The subsystem can create an enclave using the IWM4ECRE macro, and then schedule SRBs to run in the enclave using the IEAMSCHD macro.

The SYSEVENT ENCASSOC macro is used to indicate that an enclave and an address space are related for storage management purposes. The ENCASSOC sysevent is necessary only when SRBs are used. A task that joins an enclave automatically associates the home address space with the enclave.

For more information about the SYSEVENT macro, see z/OS MVS Programming: Authorized Assembler Services Reference SET-WTO.

For more information about SRBs and how to use them, see z/OS MVS Programming: Authorized Assembler Services Guide.

For more information about the IEAMSCHD macro, see z/OS MVS Programming: Authorized Assembler Services Reference EDT-IXG.