Sun Microsystems 3 manual Process Execution, Activity Types

Process Execution

Activity Types

A process definition can include a number of different activity types, each of which passes through the various activity states in a different fashion. The table below summarizes the different types of activities. For more information on activities, see the iIS Process Development Guide.

Activity type	Description
First	Specialized activity: the first activity in a process definition.
	Automatically placed in COMPLETED state, bypassing the PENDING,
	READY, and ACTIVE states.
Offered	An activity performed by client applications. Offered to sessions based
	on assignment rules and accepted by a client application from its work
	list. Passes through all states.
Queued	An activity performed by client applications. Placed on a queue and
	accepted by a client application. Passes through all states.
Subprocess	Represents a separate process executed by an engine. Passes directly
	from PENDING to ACTIVE state, bypassing the READY state.
Automatic	An activity performed directly by the engine. Not assigned to sessions.
	Passes through all states.
Last	Specialized activity: the last activity in a process definition. Passes
	directly from PENDING to a COMPLETED state, bypassing the
	intermediate states.

Process Execution

This section discusses how an engine executes an iIS process definition. Each process executes through a life cycle consisting of process instance creation, process instance execution, and process instance termination. Each of the six activity types—First, Offered, Queued, Subprocess, Automatic, and Last—plays a specific role in the overall life cycle.

Process instance creation Process creation involves the creation of a First activity.

Chapter 6 Managing Process Execution 165