Why Would You Use an Enclave?

Use an enclave when you have a transaction that spans multiple tasks or SRBs in one or more address spaces, and you want to manage it as a unit. An enclave allows you to manage and report on resource consumption in the enclave based on a performance goal unrelated to the performance goal(s) of the address space(s) in which the enclave's dispatchable units execute.

An independent enclave represents a complete transaction. Its performance goal is assigned based on the service class to which it is classified when the enclave is created. Each independent enclave starts in period 1 of its service class and switches periods based on the service consumed by the dispatchable units belonging to the enclave.

A work-dependent enclave represents a continuation of an existing independent enclave's transaction. It inherits its classification and performance goals from the independent enclave. Service consumed by a work-dependent enclave is treated as if it was consumed by the independent enclave, and can cause the independent enclave (including all associated work-dependent enclaves) to switch into later periods.

A dependent enclave represents the continuation of an existing address space transaction under a new set of dispatchable units. Its performance goal is inherited from the existing address space transaction based on the service class (or PGN) and period being used to manage the address space at the instant the dependent enclave is created. CPU service consumed by a dependent enclave is treated as if it were consumed by the address space transaction, and can cause the address space along with the dependent enclave to switch into later periods.

If your work manager does not use enclaves, work can only be managed on an address space basis, tied to the address space the work runs in. If you have a transaction that spans multiple address spaces, use an enclave to manage the transaction as a unit.

If you have an address space that executes multiple transactions, use enclaves to isolate the transactions so they can be reported on and managed individually.