upgrade.ChangeTracker Class Reference

The change tracker class keeps track of state changes and notifies interested parties. More...

Inheritance diagram for upgrade.ChangeTracker:

Public Member Functions
def	__init__
	Constructor. More...
def	changed
	Indicate that state has changed. More...
def	changeWait
	Wait for a state change. More...

Public Attributes
	parent
	Change tracker hierarchy (if you are changed, your parent is marked as changed as well) More...
	generation
	Every time a change occurs, generation is incremented. More...
	changeFlag
	Python threading Event Object that implements the fundamental thread blocking mechanism. More...

Detailed Description

The change tracker class keeps track of state changes and notifies interested parties.

Constructor & Destructor Documentation

def upgrade.ChangeTracker.__init__	(		self,
			parent = None
	)

Constructor.

Parameters

parent

Specify a change tracker hierarchy (if you are changed, your parent is marked as changed as well)

Member Function Documentation

def upgrade.ChangeTracker.changed

(

self

)

Indicate that state has changed.

def upgrade.ChangeTracker.changeWait	(		self,
			generation,
			timeout = None
	)

Wait for a state change.

Parameters

generation	What was the last state change you knew about?
timeout	Optional maximum time in milliseconds to wait for a state change

Returns

generation of this state change (pass this into subsequent calls to changeWait)

Member Data Documentation

upgrade.ChangeTracker.changeFlag

Python threading Event Object that implements the fundamental thread blocking mechanism.

upgrade.ChangeTracker.generation

Every time a change occurs, generation is incremented.

This allows users to determine whether they are up-to-date

upgrade.ChangeTracker.parent

Change tracker hierarchy (if you are changed, your parent is marked as changed as well)