Ios Simulator in Xcode 6 running at 0.0 fps - ios

Question

I know other people have asked questions about slow ios simulators before. But my problem is not the the simulator is slow. It is that the simulator runs at 0.0 fps (according to the text at the bottom) and I can't test any of my code. I am very confused and any help would be appreciated. Don't have enough reputation to post an image. But at the bottom it says 3 nodes 0.0 fps.
UPDATE
I deleted the following code from my code and it started working like normal again.
while left {
var leftMove = SKAction.moveByX(1, y: 0, duration: 0.1)
person.runAction(leftMove)
}
while !left{
var rightMove = SKAction.moveByX(-1, y: 0, duration: 0.1)
person.runAction(rightMove)
}
that was taken from my update() method
here is the whole thing...
import SpriteKit
class GameScene: SKScene {
var person = SKSpriteNode(imageNamed: "guyLeft_1.png")
var left = true
override func didMoveToView(view: SKView) {
self.backgroundColor = SKColor.whiteColor()
var ground = SKShapeNode(rectOfSize: CGSizeMake(self.frame.size.width, self.frame.size.height * 0.2))
ground.position = CGPoint(x: self.frame.size.width / 2, y: self.frame.size.height * 0.1)
ground.fillColor = SKColor.blueColor()
self.addChild(ground)
person.position = CGPoint(x: self.frame.size.width / 2, y: self.frame.size.height * 0.2)
self.addChild(person)
}
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
/* Called when a touch begins */
!left
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
while left {
var leftMove = SKAction.moveByX(1, y: 0, duration: 0.1)
person.runAction(leftMove)
}
while !left{
var rightMove = SKAction.moveByX(-1, y: 0, duration: 0.1)
person.runAction(rightMove)
}
}
}

Answer 1

It says 0fps because it is not able to render the scene just once.
Just change it to
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
if left {
var leftMove = SKAction.moveByX(1, y: 0, duration: 0.1)
person.runAction(leftMove)
}
if !left { // or use an if-else construct
var rightMove = SKAction.moveByX(-1, y: 0, duration: 0.1)
person.runAction(rightMove)
}
}
There is really not much to explain here - the while just caused an infinite loop. If you have no break statements and the while body does not alter the evaluated condition left the program will be stuck forever inside the while loop.
Additionally:
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
left = false // either
left = !left // or
}
The previous code just evaluates !left and ignores the result - effectively does nothing.