IWM4ECRE macro — Create Enclave

The purpose of this service is to create an Enclave where possibly multiple SRBs and/or TCBs may be simultaneously executing or scheduled. For the duration of each Enclave, all SRBs and TCBs associated with the Enclave are treated as part of a single work request. All SRBs and/or TCBs associated with the Enclave accumulate service as a single entity and are managed as a single entity. The address spaces where Enclave SRBs are dispatched, as defined by the ENV= parameter of IEAMSCHD, should be non-swappable.

For more information about managing address spaces with enclaves, see: "Performance Management of Address Spaces with Enclaves".

For TYPE=INDEPENDENT Enclaves, a new work business unit of work is created and classified according to the input Connect token's subsystem type and subsystem name, along with whatever other attributes are passed via the Classify parameter list. The current home address space is considered the owner.

For TYPE=DEPENDENT enclaves, SRM considers the enclave to be part of the current home address space's transaction, which then becomes the owning space. This space need not be connected to WLM via IWM4CON.

For TYPE=WORKDEPENDENT, SRM considers the new enclave to be a continuation of the creating unit of work's (TCB or SRB) transaction. The resulting enclave's type depends on the caller's execution environment: If the caller has joined or is scheduled into an enclave of type independent, the resulting enclave will be of type work-dependent and is regarded as an extension of the independent enclave's transaction. Classification and owner address space is adopted from the independent enclave. If the caller has joined or is scheduled into an enclave of type work-dependent, the resulting enclave will be of type work-dependent, as well. It is considered a part of the underlying independent enclave's transaction and inherits owner address space and classification from that independent enclave. If the caller has joined or is scheduled into a dependent enclave, the resulting enclave will be of type dependent. The new enclave is considered part of the creating enclave's (i.e., the enclave the caller is running in) owner address space's transaction and inherits its classification. The creating enclave's owner address space will become the owner of the new enclave. Finally, if no enclave has been joined when the service is called, the resulting enclave will be as if the service had been invoked with TYPE=DEPENDENT specified. Note that it is not allowed to invoke this service with TYPE=WORKDEPENDENT specified while running in a foreign enclave.

For TYPE=MONENV enclaves, SRM considers the enclave to be part of the address space's transaction which is delayed according to the input management monitoring environment, as set when IWM4MINI or IWM4MRLT was used. This space becomes the owning space. This space need not be connected to WLM via IWM4CON.

For both TYPE=MONENV and TYPE=DEPENDENT enclaves, SRM will change the enclave to TYPE=INDEPENDENT if the owning address space's transaction ends.

For both TYPE=MONENV and TYPE=DEPENDENT enclaves, SRM will check the enclave for period switch when the owning address space is swapped in. If the owning address space is swapped out SRM will continue to accumulate service for any enclaves owned by the space, but will not check the address space or any owned enclave for period switch until the address space is swapped in again. The presence of enclaves does not make the address space appear to be ready from an SRM point of view.

Enclaves are deleted if the owning address space terminates. TYPE=INDEPENDENT enclaves are deleted if the owning address space disconnects or the TCB which connected terminates. Work-dependent enclaves are implicitly deleted when the owning independent enclave is deleted.

Enclaves should only be created when this environment is ready for execution, and should not be used when prolonged queueing effects are possible prior to the scheduling of the first SRB (IEAMSCHD) or the first TCB join (IWMEJOIN). "Prolonged" would certainly include times measured in seconds. The service allows the caller to pass the queueing time prior to creation of the Enclave so that this may be separately reported.