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Resources manager

The Resources manager is an efficient tool to manage resources between behaviors.

For example, if two Behaviors using the Audio player resource are executed at the same time, you will want them to obey to a certain priority rule such as “if the first behvior is using the resource, the second has to wait the end of the first behavior”.

In this tutorial will see how to manage this kind of situation over several examples.

Without resource management

Let’s create the Behavior on which we will be working all along the tutorial:

Step	Action	Further help
	Drag and drop two Audio > Sound > Play sound box onto your root diagram.
	Drag and drop a Flow Control > Time > Wait box onto your root diagram and set the timeout parameter to 4 seconds by clicking on the Parameter button.
	Link the input of the first Play Sound box to the beginning of the root diagram.
	Link the input of the second Play Sound box to the output of the Wait box and link the input of the Wait box to the beginning of the root diagram. Your diagram should look like that: Note The Wait box is here to delay the second Play Sound box in order to start its execution when the first Play Sound box has taken the audio player resource.
	For both Play Sound boxes, set the music file. Warning Choose 2 long enough and different musics, in order to be able to detect wich box is executed.
	Start the behavior using the Play button. Without using the Resources manager, NAO plays both music together. Let’s see how we can fix this problem, using the Resource manager.

Lock the resource

In this part of the tutorial we will see the effect of taking resources in both Play Sound box.

Step	Action	Further help
	For both Play Sound boxes: Right click the box, and choose Set Resources in the contextual menu. In the resources list select the Audio > Speakers > Audio player resources. Note If you want to select several resources you can continuously press the Ctrl key and select other resources. Click the Ok button.
	Start the behavior using the Play button. The first Play Sound box is executed and the second is not because the first one has locked the resource.

tutorial_attached_file.crg

Stop on demand

In this part will see how we can stop a box that has already locked the resource.

Step	Action	Further help
	On the first Play Sound box, go to the Resource editor as we did before.
	Change Lock to Stop on demand.
	On the second Play Sound box, go to the Resource editor.
	Change the timeout(s) into Wait n seconds....
	Set the number of second to 1.
	Start the behavior using the Play button. The first Play Sound box is executed and stopped by the execution of the second Play Sound box after one second.

tutorial_resource_manager_stop_on_demand.crg

Callback on demand

With the Resource manager, when a resource is locked by a behavior, it is possible to call a method when another behavior tries to take the resource too. In this section will see how it works.

Step	Action	Further help
	On the first Play Sound box, go to the Resource editor as we did before.
	Change Stop on demand to Callback on demand.
	Click the Ok button.
	Right click the same box and choose Edit box script in the contextual menu to open the Script editor. You can see that the structure of the code was automatically generated.
	Add an onResource method to the script and make NAO says something using the ALTextToSpeech module. The code of the box should look like that: class MyClass(GeneratedClass): def __init__(self): GeneratedClass.__init__(self) def onLoad(self): self.bIsRunning = False self.tts = ALProxy('ALTextToSpeech') def onUnload(self): self.bIsRunning = False def onInput_onStart(self): self.bIsRunning = True def onResource(self, resource): self.tts.say("Someone wants to take my resource " + resource) def onInput_onStop(self): if( self.bIsRunning ): self.onUnload() self.onStopped() The method onResource will be called when another behavior will want to take the resource.	ALTextToSpeech
	Start the behavior using the Play button. The first behavior is executed and when the second behavior tries to lock the resource, the first one call the onResource() method. You can hear your robot talking.

tutorial_resource_manager_callback_on_demand.crg

Pause on demand

The pause on demand option can be apply only on Timeline box.

In this section, will see how to pause an animation because another behavior wants to take a resource already taken by the animation.

Step	Action	Further help
	Drag and drop the Motion > Animation > Hello box onto your diagram.
	Right click on it and choose Edit resources in the contextual menu.
	In the resources list select the Audio > Speakers > Audio player resource, this should deselect all the resources already selected.
	Change Lock to Pause on demand.
	Replace the first Play sound box by the Hello box. Your diagram should look like that:
	Start the behavior using the Play button. The animation is started, paused when the Play sound box is executed, and restarted when the resource is released.

tutorial_resource_manager_pause_on_demand.crg

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