Creating an Enclave

The IWM4ECRE service creates an enclave. An optional parameter indicates whether the work manager implicitly starts an EWLM work request:

• ESTRT=IMPLIED specifies that a work request is started implicitly when the enclave is created.
• ESTRT=EXPLICIT specifies that the work manager explicitly indicates the start of an EWLM work request by invoking the IWMESTRT service.
• ESTRT=EXPLICIT_SINGLE specifies the same as option ESTRT=EXPLICIT and, in addition, the application ensures that only one work request is active. No nested calls to IWMESTRT are allowed.

  If the ESTRT=EXPLICIT_SINGLE option is specified, the CPU consumption on all EWLM enclave services (IWMEGCOR, IWMESTRT, IWMESTOP, IWMEBLK, IWMEUBLK) will be reduced.

  For further details refer to the corresponding macro descriptions.

• ESTRT=NEVER specifies that this enclave will never use any EWLM-related enclave services (IWMEGCOR, IWMESTRT, IWMESTOP, IWMEBLK, IWMEUBLK) after the enclave has been created, even if the work manager has registered (IWM4CON or IWMCONN) with EWLM=YES. Also, IWM4ECRE will not start an EWLM work request on the enclave and will not do any EWLM-related processing.

The use of the ESTRT parameter is allowed only when the work manager previously connected to WLM with IWM4CON EWLM=YES.

An optional parameter, WORKREQ_HDL, allows the caller to get the work request handle of an implicitly created work request. The handle can be used subsequently with any of the other new services (IWMEBLK, IWMEUBLK, IWMESTOP and IWMEGCOR). The WORKREQ_HDL parameter is valid only with ESTRT(IMPLIED).

For more information, see IWM4ECRE macro — Create Enclave.