Reducing CPU Usage of Main GUI Loop

[balajeerc]

Using the example found in _example/twitterstream, my GUI loop in the main thread is setup as shown below:

var uiLock sync.Mutex
var alive bool = true

func InitGUI() {
	runtime.LockOSThread()
	gtk.Init(&os.Args)
}

func RunGUILoop() {
	for alive {
		uiLock.Lock()
		alive = gtk.MainIterationDo(false)
		uiLock.Unlock()
	}
}

func safeCallGUI(guiChange func()) {
	uiLock.Lock()
	defer uiLock.Unlock()
	guiChange()
}

This lets me use the uiLock mutex to safely make changes to the GUI in other goroutines, and this works well.

However, doing this basically jacks up the CPU usage of this process due the rather busy loop in which gtk.MainIterationDo(false) is called.

My first shot at reducing the CPU usage was to add a time.Sleep:

	for alive {
		uiLock.Lock()
		alive = gtk.MainIterationDo(false)
		uiLock.Unlock()
		time.Sleep(20000 * time.Microsecond)
	}

The trouble with this is that while it cuts down CPU usage, it adds a perceptible delay to any GUI event handling. I managed to tweak it to a sweet spot of 10000 microseconds to get an acceptable GUI event responsiveness as well as felling CPU to 1%.

However, I reckon that perhaps there is a more elegant way to do this? Any suggestions?