Search Results subscribe_for_acks

Overview

XNP_EVENT is the event management engine within the Oracle E-Business Suite Advanced Supply Chain Planning and Transportation Management (ETRM) module. It provides the runtime infrastructure that allows ETRM applications and external systems to interact asynchronously through a publish-and-subscribe model built on Oracle Advanced Queuing and the Business Event System. The package coordinates inbound and outbound messaging, dispatches internal events, manages timer-based triggers, and controls the lifecycle of callback procedures that applications register against specific message codes. Internally, the package relies on four queue constants — XNP_IN_MSG_Q, XNP_OUT_MSG_Q, XNP_IN_EVT_Q, and XNP_IN_TMR_Q — which map to the inbound message, outbound message, internal event, and timer queues respectively. Because it sits at the heart of ETRM messaging, XNP_EVENT is referenced by 66 other packages, making it one of the more widely depended-upon APIs in the schema.

Key Procedures and Functions

Fifteen procedures and functions are documented. The registration APIs are SUBSCRIBE, which registers a callback procedure against a message code and reference, and SUBSCRIBE_FOR_ACKS, which subscribes a callback for all acknowledgements of a given message type. The corresponding teardown APIs are UNSUBSCRIBE, which deregisters a specific callback using an event ID and process reference, and the two overloaded DEREGISTER procedures, one keyed on message code and reference ID and one keyed on order ID. A further variant, DEREGISTER_FOR_WORKITEM, removes all callbacks tied to a particular workitem instance. Execution-side procedures include PROCESS_IN_MSG for dequeuing and routing inbound messages, PROCESS_IN_EVT for internal events, and PROCESS as the general dispatcher. Workflow integration is handled by RESUME_WORKFLOW and SYNC_N_RESUME_WF, which re-activate suspended workflow processes. RESTART_ACTIVITY — the procedure the user searched for — re-invokes a workflow activity whose previous execution was interrupted, allowing a failed or stalled step to be retried without rebuilding the parent process.

Tables Accessed

The package maintains its configuration and audit state in several ETRM tables accessed through APPS synonyms. XNP_CALLBACK_EVENTS and its sequence-backed shadow XNP_CALLBACK_EVENTS_S hold the registered subscriptions created by SUBSCRIBE and consumed during callback dispatch. XNP_MSGS stores message instances processed by PROCESS_IN_MSG. XNP_MSG_ACKS records acknowledgement traffic handled by SUBSCRIBE_FOR_ACKS. XNP_MSG_TYPES_B defines the valid message types used as subscription keys. DBMS_LOCK is invoked for serialization so that concurrent dequeuing sessions do not collide on the same callback or message row.

Usage Notes

XNP_EVENT is rarely called directly from forms. It is invoked primarily by ETRM concurrent programs and by the event manager agent that polls the queues, and by custom PL/SQL code that needs to register a callback or restart a stalled workflow activity. The typical pattern is to call SUBSCRIBE during setup, let the event manager invoke PROCESS_IN_MSG or PROCESS_IN_EVT on the queues, and use DEREGISTER or UNSUBSCRIBE at teardown. The procedures accept NOCOPY OUT parameters for error codes and messages, so callers should always inspect x_error_code after invocation. Because the package is compiled AUTHID CURRENT_USER, execute privileges and synonym resolution must be granted to the calling schema.