You’re almost correct about the references I think. It’s quite clear that the GC is running and is causing the issues, but you DO have references to the objects because of the event listeners. However, since the GC is running I’m assuming that these are weak references which I presume means that the GC is going to grab them anyway.

Please do correct me if I’m wrong, I’m very interested in more info about the GC and how it works.

I ran into that issue on the first Flash9 / AS3 project I worked. Got so fed up I emailed Robert Penner, and he suggested that might be the problem.

I second Tweener.

Looks like my App got cut off, here it is:

Ok, this is working poorly. Make a new Flex Applicaiton. Put

creationComplete=”init()”

in the App tag.

Throw this is a Script tag:

import Actor;

public var actorCounter:uint;
public var timer:Timer;

public function init():void {
trace(”init()”);
timer = new Timer(100);
timer.addEventListener(TimerEvent.TIMER, onTimer);
timer.start();
}

public function createActor():void {
trace(”createActor()”);
var actor:Actor = new Actor(actorCounter++, timer);
}

public function onTimer( evt:TimerEvent ):void {
trace(”onTimer()”);
createActor();
txtArea.text += “Created Actor “+actorCounter+”\n”;
}

and put this on the stage of a new Application:

Ok, I think I understand the root of the problem you’re getting at now. It’s a pretty simple issue.

The problem of not catching the events is not “garbage collection,” it is that the events you’re watching for are firing before you addEventListener() to catch them. There is no guarantee that you should be able to catch a Event.COMPLETE on a loader or a TweenEvent.MOTION_FINISH after setting the processor to create that event into action previously. If you really want to catch the events, the objects to be watched needs the event listeners added before you tell them “go!”

I’m firmly convinced your work around is just getting lucky catching the events, perhaps because it takes longer to process assignments/instantiation into class memory than local.

To really solve your Tween problem, you should have a handler for the clip ending on the listener argument object passed to the Tween on creation. That is

var t:Tween = new Tween(listener…)

in listener class:
public var onTweenEnd():void { // handle it! }

Check the livedocs on the Tween class for details.

It seems the solution is built right into the Flex architecture and is not being used. If all your programmatic Tweens are based on event catching, check an see if this solution doesn’t fix the issue.

user411, I think you’re talking about mx.effects.Tween and the author was talking about fl.transitions.Tween for Flash CS3. They are different.

I tried your last example, but I think actors don’t die because they are referenced by their own timer instances, which in turn are referenced by something! Take a look at the sample below. Locally created Timer instance is never GCed even though there is no reference to it from my code.

package {
import flash.display.Sprite;
import flash.events.TimerEvent
import flash.system.System;
import flash.utils.Timer;

public class Main extends Sprite {
private var sprite:Sprite;

public function Main():void {
sprite = new Sprite();
sprite.graphics.beginFill(0xff0000);
sprite.graphics.drawRect(0, -5, 100, 5);
sprite.x = 150;
sprite.y = 150;
addChild(sprite);

var timer:Timer = new Timer(1000);
timer.addEventListener(TimerEvent.TIMER, onTimer, false, 0, true); // weak reference
timer.start();
timer = null; // clear local reference to timer
}

public function onTimer(event:TimerEvent):void {
sprite.rotation += 10;
tryGC();
}

public function tryGC():void {
trace(”before: ” + String(System.totalMemory));
var array:Array = new Array();
for (var i:uint = 0; i < 100000; i++) {
array.push(”abcdefghijklmnopqrstuvwxyz”);
}
trace(”after: ” + String(System.totalMemory));
}
}
}

Josh: Thanks for clarifying that bit!

Jensa: I’d actually like to throw a punch for TweenLite. It’s very fast and lightweight, as well as incredibly easy to use. We’ve been using it for a while now.

It’s not just Tweens either.

I know this is a bit after the fact, but thanks for posting this article. I had been banging my head against the keyboard for a while now trying to track down why my tweens were not finishing. And then I finally dug this article up.

This article ended up leading me to abandon Adobe’s tween engine and go with TweenLite instead, which I have to say - aside from solving my incomplete tween problem - is just easier to work with all around.

Thanks again.

It worked, after a week of head-banging over the walls, this helped me thanks!

[...] 之前的AS3开发中，我一直用的Adobe官方的fl.transitions.Tween，虽然不怎么好用但是基本功能能满足。但是最近做了一个项目中中，碰到了一个问题，很多tween同时执行时，偶尔会出现所有动画同时半途停止的现象。google了一下英文资料，发现问题出在“AS3的垃圾回收器把tween对象给回收了”。匪夷所思？看看这里的解释和解决办法。 [...]

Mate! that saved my bacon your a STAR

[...] 见AS3 Garbage Collection, the reason your tweens are ending early. [...]

I didn’t get a chance to read all the responses to this post, but I was having the same issue with tweens getting cut off and I chalked it up to Garbage Collection as well. The solution I found was to create your variables for the tweens outside of the function, so they are in the global scope, then add the tween after when needed.

var movement:Tween;

function yourFunction(event:Event):void
{
movement = new Tween(yourMC, ….
}

This way when the garbage is taken out, it only takes the actual tween, and not the variable.

Thanks for the post, it solved a problem for me. If your ever in the philly area , drinks on me boss

[...] I used a method found here to force the Tween to fully [...]

I know this is the solution to my problem, a class variable should stop overwriting the loader. What I don’t understand is how to pass the right part of the class variable based on the event down in the finishLoadImage function. (Hoping this little extraction makes sense.)

The problem I have is that if I roll in and out too fast the movieclip with the image is getting deleted before it is finished loading. I sure could use a little advice on how to proceed. Thanks! And thanks for this great explanation.

function rollover(e:Mousevent)
{
loadImage(ID,…);
}
function loadImage(ID,…)
{
var loader:Loader = new Loader(); loader.contentLoaderInfo.addEventListener(Event.COMPLETE,finishLoadImage);
loader.load(new URLRequest(path));
//etc
}

function finishLoadImage(e:Event)
{
var IDhere = event.target.loader.parent.name;
//positions image
}

Great thanks to you sir. Was stumped as to why my tweens were finishing early. Eliminating the garbage collection issue has eradicated the problem

Just forgot to say I still like other cleaner solutions better than keeping track of all tweens, with this class.

For instance saving the tweens inside the instances you are moving.
Just as an example (untested code):

public class MoveMe extends MovieClip {
public var myTween1;
…
}
var aMoveMeInst:MoveMe=new MoveMe()

aMoveMeInst.myTween1=new Tween(aMoveMeInst,…

This way, if you have 100 sprites, each will keep its own Tween (or tweens if more) untill the sprite itself gets GC.

Thanks again,

Francesco

Thanks! This tween thing nearly drove me crazy.