Throttling Service Notifications
I posted an update on the DSS Wiki page that describes how you can use CCR task execution policy, for managing periodic notifications. You can basically have the CCR do the work of keeping your service with only one queued task, only for the most recent notification.
Check it out here, towards the bottom
http://channel9.msdn.com/wiki/default.aspx/Channel9.DssPatterns
Here is the code snippet as well
Let assume you have the usual code snippet where you subscribe to a sensor, and supply a notification port to receive the update messages. I cut and pasted a simple example from robotics Tutorial 2 (as is):
void SubscribeToBumpers() { // Create bumper notification port bumper.ContactSensorArrayOperations bumperNotificationPort =new bumper.ContactSensorArrayOperations(); // Subscribe to the bumper service, send notifications to // bumperNotificationPort _bumperPort.Subscribe(bumperNotificationPort); // Start listening for Bumper Replace notifications Activate( Arbiter.Receive<BUMPER.Update> (true, bumperNotificationPort, BumperHandler)); } I would modify it as follows (seeboldface text below): void SubscribeToBumpers() { // Create bumper notification port bumper.ContactSensorArrayOperations bumperNotificationPort =new bumper.ContactSensorArrayOperations(); // Subscribe to the bumper service, send notifications to // bumperNotificationPort _bumperPort.Subscribe(bumperNotificationPort); DispatcherQueue notifyTaskQueue =newDispatcherQueue("bumperNotifyQueue", TaskQueue.Dispatcher,// use same dispatcher as service TaskExecutionPolicy.ConstrainQueueDepthDiscardTasks, 1// maximum depth set to 1, will discard anything but latest ); // Start listening for Bumper Replace notifications Arbiter.Activate( notifyTaskQueue, Arbiter.Receive<BUMPER.Update> (true, bumperNotificationPort, BumperHandler)); }
