The XA interface is a part of a DTP model defined by X/Open.

The XA interface defines how the transaction manager and resource manager communicate with each other. UAPs do not use the XA interface directly. The following table lists the XA library subroutines used by OpenTP1 and the resource manager.

Table 3-3 XA library subroutines

No.	Function name	Description
1	ax_reg	Registers the resource manager in the transaction manager.
2	ax_unreg	Unregisters the resource manager from the transaction manager.
3	xa_close	Closes the resource manager.
4	xa_commit	This function notifies the resource manager that all the resource managers will be committed after they are found to be committable (in the prepare status).
5	xa_end	Notifies the resource manager that the transaction has ended.
6	xa_forget	Notifies the resource manager that the information about the ended transaction can be discarded at the discretion of the resource manager.
7	xa_open	Opens the resource manager.
8	xa_prepare	Notifies the resource manager that the transaction is being committed.
9	xa_recover	Obtains a list of undetermined transactions in the resource manager.
10	xa_rollback	Notifies the resource manager that the transaction is to be rolled back.
11	xa_start	Notifies the resource manager that the transaction was started or restarted