Sequence of CSL SCI requests
Structured Call Interface (SCI) requests must be issued in a particular sequence in order to successfully register to SCI, ready the member, release storage allocated for the member, quiesce the member, and deregister the member from SCI.
The first SCI request is CSLSCREG. The member can then issue CSLSCRDY to tell SCI that it is ready to receive messages and requests that are routed by member type. If a member has storage that is allocated by SCI (for example, a message or an SCI allocated output parameter is received), the SCI buffer release request, CSLSCBFR, is issued to release the storage.
When a member is ready to terminate, the SCI quiesce request, CSLSCQSC, is used to tell SCI that the member does not want to receive messages and requests that are routed by member type. After the SCI deregistration request, CSLSCDRG, is used to terminate the connection with SCI, the member can no longer participate in the IMSplex.
The following table lists the sequence of requests issued by an SCI client. The request is listed with its purpose.
| Request | Purpose |
|---|---|
| CSLSCREG | Register to SCI, which establishes the connection with SCI and enables the member to communicate within the IMSplex. |
| CSLSCRDY | Readies the member to SCI, which allows SCI to route messages and requests that are routed by member type to this member. |
| CSLSCBFR | Releases storage allocated for the member by SCI (for example, message data or parameters allocated by SCI from a request). |
| CSLSCQSC | Quiesces the member to SCI, which tells SCI not to route messages and requests that are routed by member type to this member. |
| CSLSCDRG | Deregisters the member from SCI which ends the member's connection with SCI. |