State tables for APPC mapped conversations at sync level 2

The GDS ISSUE SIGNAL command and the CDBSIG flag

In the tables, the CDBSIG flag is not mentioned. This is because its use is optional and is entirely a matter of agreement between the two conversation partners. In the worst case, it can occur at any time after every command that affects the CDB flags. However, used for the purpose for which it was intended, it usually occurs after a GDS SEND command. Its priority in the order of testing depends on the role you give it in the application.

The CDBSIG flag is set when the partner issues the GDS ISSUE SIGNAL command.

State changes for the SYNCPOINT and SYNCPOINT ROLLBACK commands

When the SYNCPOINT and SYNCPOINT ROLLBACK commands are issued, they are propagated on, and affect the state of, all the conversations that are currently active for the task, including MRO conversations.

Following rollback, the conversation can be in SEND or RECEIVE state, depending on the conversation state at the start of the current distributed unit of work. The conversation can be in FREE state if it ended abnormally due to session failure or due to deallocate abend being received, or if the partner transaction issued a SEND LAST WAIT or FREE command.

After a syncpoint or rollback, it is advisable to determine the conversation state before issuing any further commands against the conversation.

State changes following the ISSUE PREPARE command

Although ISSUE PREPARE can return with the conversation in either SYNCSEND state, SYNCRECEIVE state, or SYNCFREE state, the only commands allowed on that conversation following an ISSUE PREPARE are SYNCPOINT and SYNCPOINT ROLLBACK. All other commands abend.

State tables