GUI control flow

The GUI architecture¶

The CosmoSim class from CosmoSim.GUI.CosmoSim sets up the simulator environment for the GUI. This provides two features which are critical for the GUI,

1. Threading to allow the simulator to run without holding up the GUI.

2. Interface to change lens and simulator parameters without reinstantiating the objects.

Thread and Event Model¶

The CosmoSim class makes sure that only one call to run the simulator is made at the time, and that it is rerun if the parameters has changed while running.

The CosmoSim object defines the following

• Events

  • updateEvent

  • simEvent

• Threads

  • simThread

The simThread (thread and function) loops. waiting for a simEvent to

1. clear the event

2. run the simulator (runSim()) in the C++ code).

3. set an updateEvent to trigger update of the GUI.

To avoid race conditions, it is critical that runSim() is only ever run from the simThread. To call the simulator, the runSimulator() method should be used instead. This function simply sets the simEvent.

There is a thin python wrapper to the runSim() method. All it does is to snapshot the source model as an attribute, to prevent it from being garbage collected while the simulator is running.