New Feature: handling a lost device context

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New Feature: handling a lost device context

(58 posts) (19 voices)

Started 1 year ago by Daniel
Latest reply from wrench

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Jeff

Moderating Owl
Joined: Nov '11
Posts: 1,285

@phoenixperry

If you are adding a child to your GameMain which is your root object you would be better off adding that child in the root object's constructor or in a listener for the root object's 'added to stage'.

Whenever you use use a Event.CONTEXT3D_CREATE listener on your startup class you are not only going to get this called on startup but potentially multiple times every time a context is lost.

Alternatively, your root object is only going to get initialized once even if contexts are lost later on.

Posted 1 year ago #
phoenixperry

Competent Bird
Joined: Jan '12
Posts: 54

Yep. I realize this. I posted it anyway because right now it's a preferred way
to turn on debug draw elsewhere in the forum. I think I am going to throw it in a keypress so I can debug at will.

Posted 1 year ago #
numa

Novice Bird
Joined: Feb '12
Posts: 12

Starling.handleLostContext works like a charm, even for mobile (tested with Galaxy S, Galaxy SII, Motorola Defy). I didn't seen any performance issue.

Posted 1 year ago #
Sev

Novice Bird
Joined: May '12
Posts: 7

I've had a bit of an odd problem that I think is related to Context loss.

I have handleLostContext set to true, and on some Android phones, if you lock the phone whilst my game is running it would fail to come back - you would get this weird black screen. I would also sometimes get the wrong orientation, and lost full screen.

As a test, I turned off handleLostContext, and then I started to see the critial error message the context was lost.

It looks like an Air problem, but it also looks like starling was failing to resume from the context lose?

Finally, and this is just weird, but the black screen for some reason would have one bitmap data displayed - the progress bar that I have on my preloader. I have no idea what it is doing there because it is destroyed and disposed after the app is initially loaded... so... yeah.

Posted 1 year ago #
Jeff

Moderating Owl
Joined: Nov '11
Posts: 1,285

You mention a preloader so I'll throw this possibility out there in case, but one of the requirements when setting handleLostContext = true is that you cannot call dispose on any bitmapData you might have created to load textures because Starling's texture will keep a reference to the original bitmapData to be able to reload the textures on context loss.
(hence where the extra memory hit comes from when you use handleLostContext)

As a second source of 'missing content', if you are using any live RenderTextures in your app they do not get recreated on context loss so you will need to re-establish any RenderTextures yourself if you happen to use them as live textures for any of your app sprites.

Posted 1 year ago #
Sev

Novice Bird
Joined: May '12
Posts: 7

Hi Jeff - thanks for the ideas.
The preloaded texture is actually not used in Starling at all. I just have a regular flash sprite with some normal Bitmaps on the screen until all the starling stuff has loaded. That's what makes it so odd - once everything is loaded, the sprite and all of the Bitmaps it contains is removed and disposed

Also, I am not using any RenderTextures in the game, so it couldn't be that either.

I'm really stumped for ideas

Posted 1 year ago #
Sev

Novice Bird
Joined: May '12
Posts: 7

Ok, so, I am a bit of an idiot.

Turns out in my Texture loading class I was disposing the BitmapData's after I generated the textures.. soo... yeah... sorry about that one.

I still think it was odd that the old bitmap data graphics were being displayed on stage after the context was lost.

Posted 1 year ago #
ninjabonsai

Competent Bird
Joined: Nov '11
Posts: 34

hey.. i've got Starling.handleLostContext set to false on iOS and all's well except when launching CameraUI, taking a photo and then coming back. sometimes i get the lost context error. setting to true sorts this out but i guess there is a downside? more memory yeah? it seems to only lose the context if i've been jumping around the app a lot, instantiating big textures, disposing them, going somewhere else, back and forth.. then in an out of CamerUI.. lost context

every big screen change in the app i call this

System.pauseForGCIfCollectionImminent();

anyone use this much? what's a good amount to put here as an argument?
what about just calling System.gc() ?

cheers

Posted 8 months ago #
Jeff

Moderating Owl
Joined: Nov '11
Posts: 1,285

Yikes, this is a pretty significant find if iOS can cause lost context too. It has been pretty well spread around that iOS *never* lost context.

What AIR SDK version are you using? 3.4?

Maybe it is something only triggered when using CameraUI (hopefully)

Posted 8 months ago #
ninjabonsai

Competent Bird
Joined: Nov '11
Posts: 34

yeah.. i didn't believe it when a colleague told me. it's Air 3.4, Starling 1.2, iOS 5.1 iPad 2

i've since cleaned up the code a bit in the rest of the app, calling System.gc() before loading new sections of the app and it's not doing it anymore.. at least it seems that way for now. but it definitely was losing context when returning from CameraUI before i made those changes and i have been able to switch handleLostContext back to false

Posted 8 months ago #
phillipk

Novice Bird
Joined: Oct '12
Posts: 6

I have the same problem--on iPads I crash (with the red fatal error re: lost context) when returning from the camera. It's not every time which makes it hard to track down. I actually haven't done a ton of testing yet so who knows. I'll try to make a small reproducible case.

Posted 7 months ago #
Daniel

Primary Feather
Joined: Jan '10
Posts: 2,437

If you can create a reproducible project, I'll forward it to Adobe -- hopefully that's something that can be fixed on their side.

Posted 7 months ago #
phillipk

Novice Bird
Joined: Oct '12
Posts: 6

I can reproduce it every time now so that's good... I launch my app, click (my) camera button, switch to front-facing camera, take a snap, click "use" and crash. iPad3, iOS6, air 3.4... how do I check the starling version? Anyway, I'll make an abbreviated example to let folks test.

Posted 7 months ago #
Patrick

Senior Bird
Joined: Jul '12
Posts: 75

I just had my first case of using LostContext and so far it works great. I am using this ANE http://darkredz.com/ios-uiwebview-and-videoplayer-native-extension-for-air-mobile/
I am launching videos from my Starling app that need to be played in the iPads native player.
This ANE allows me to listen for when the native iOS video player quits.
I have methods that rebuild the current screen allowing me to dispose of my bitmapData.

I have battle tested this pretty hard and haven't been able to crash my app yet.
Just wanted to report my findings so far.

Hope this helps
- Patrick

Posted 7 months ago #
phillipk

Novice Bird
Joined: Oct '12
Posts: 6

This is driving me nuts. It seems like it's related to memory because when I trim things way down I don't get the crash--but when I have a medium memory usage it crashes--it just takes a long time (of jumping back and forth to the cameraUI).
Starling.handleLostContext = true;
has no impact as far as I can tell. I DEFINITELY get the crash on iPad with handleLostContext set to true... Starling v 1.2

I tried throwing System.gc() in strategic locations (among many other ideas I had). I have to strip out business details but will post the source shortly.

Posted 7 months ago #
phillipk

Novice Bird
Joined: Oct '12
Posts: 6

seems like I might have it under control. I was wrong about having handleLostContext set to true... now it is, and all the bitmapDatas have no dispose() and it's all working (well, it does lose context but then recovers after a second).

Posted 7 months ago #
ninjabonsai

Competent Bird
Joined: Nov '11
Posts: 34

i'm still getting this problem too.. but just on iPad 3 not 2 which is strange. is the best solution to set Starling.handleLostContext = true ?

Posted 7 months ago #
phillipk

Novice Bird
Joined: Oct '12
Posts: 6

I spent a lot of time trying to narrow it down. The hard part was when I scaled things back it seemed to just take longer until the problem occurred. There's some deal where iOS will really kill dormant apps when many other apps come to the front. Like if you leave your app de-active and launch 10 new apps it'll reset your app. I'm sure there's a better way to explain this--but the lost device when going to cameraUI seemed connected to how deeply in the past my app was placed. With handleLostContext=true you can't dispose() any bitmapDatas you want back.

Anyway, yeah, I think the only solution (that I'm gunna use for now) is setting it to true. I don't see a memory problem but I'm also being very careful and don't have a super intense app.

Posted 7 months ago #
ninjabonsai

Competent Bird
Joined: Nov '11
Posts: 34

ah ok.. i might go with that option too. was trying to avoid it if possible

cheers

Posted 7 months ago #
ninjabonsai

Competent Bird
Joined: Nov '11
Posts: 34

i've tried setting Starling.handleLostContext = true and now other parts of the app are unstable, i guess because it uses more memory having this on. so that's out.
i guess it's an issue with cameraui and the air runtime on ios. i'll put together a small example to send to adobe..

Posted 6 months ago #
ninjabonsai

Competent Bird
Joined: Nov '11
Posts: 34

ok.. i have a small example

https://dl.dropbox.com/u/34666094/CameraUItest.zip

but it won't lose context! dam. i was really hoping it would fail

so i guess when it does lose context there are many other things happening, something with the amount of memory the app is using. someone feel free to download my example and try to get it to lose context coming back from CameraUI

Posted 6 months ago #
phillipk

Novice Bird
Joined: Oct '12
Posts: 6

sorry to not look at your example--but I found when I simply changed handleLostContext to true that my app got crazy slow. It seemed like a non-starter. But once I cleaned up a few bitmaps (basically NOT calling dispose()) it seemed to fix it. I guess my point is that the promised (threatened) memory issues using handleLostContext didn't really come true. It could be something easy.

FWIW I'm pretty confident I'm not seeing handleLostContext anymore. Instead (when there's a problem) it returns to my app and after a pause, recovers (with the recent picture I shot while in camera).

Posted 6 months ago #
alan_langlois

Competent Bird
Joined: Jul '12
Posts: 28

I've experienced the same kind of issue with the iAD ANE (from milkmangames):
http://forum.starling-framework.org/topic/starling-ios-iad-context-lost

Can't really use handleContextLost = true because I'm pretty short in memory (on the ipod). I'm considering disable iAD on ipod, and try to set the handleContextLost to true on ipad 2&3 / iphone when or if it works...

Posted 6 months ago #
JinXu

Hatchling
Joined: Dec '12
Posts: 1

In my iOS project, device context lost when using stagewebviewer to play video. if user click the ZOOM button which in video play control bar, flash dispatch "CONTEXT3D_CREATE" event, and a error throwed out after starling reinitializing. handleContextLost = true,did not work correctly.

Posted 5 months ago #
fukhaos

Expert Bird
Joined: Mar '12
Posts: 213

@JinXu same error !
=(

Posted 5 months ago #
Jeff

Moderating Owl
Joined: Nov '11
Posts: 1,285

I just stumbled across a very specific case where lost context can occur on OS X desktop AIR app. If you use PrintJob and initiate the native print panel, context will be lost on the mac desktop Stage3D window after a PrintJob.start.

This isn't a big deal since in my desktop AIR app I am already setting handleLostContext = true just to handle the Windows runtime case since we all know this is a more common occurrence.

While it is common practice (and even mentioned in the Starling docs) that you shouldn't normally need to set handleLostContext = true on either iOS or OS X, I think it might be prudent to mention this could be needed on iOS or OS X if other native window/dialogs are also triggered by your app.

Others seem to also trigger lost context on iOS when using certain ANEs that trigger other OS windows. It is probably the case that most apps still won't need to turn it on, but good to know if you are planning to trigger other native windows.

It isn't clear whether these losses are unavoidable by Adobe/Stage3D or just cases they can improve upon to avoid lost context. (other native windows like Save/Open dialogs on desktop don't cause lost context on OS X, also the CameraRoll.browseForImage doesn't on iOS)

(I know most of us would prefer a world where lost contexts are non-existent)

Posted 5 months ago #
cevinius

Hatchling
Joined: Jun '12
Posts: 1

Hi all,

I've been using Starling for a while, but decided to start playing with Away3D during this holiday period.

I was trying out sharing the context between Starling and Away3D as per this tutorial: http://www.adobe.com/devnet/flashplayer/articles/away3d-starling-interoperation.html

I noticed that I get the lost context error if I lock the screen and come back. (The debugger stops at a null pointer reference inside QuadBatch.as)

Starling's handleLostContext seems to work great for me, and other Away3D examples seem to also cope with lost context... So, I'm wondering if it's related to sharing the context? If so, does anyone have suggestions on resolving this?

Thanks,
Kevin

Posted 4 months ago #
wrench

Senior Bird
Joined: Jun '12
Posts: 176

@JinXu @fukhaos - did you ever get around this loss of context issue playing fullscreen video on iOS? I'm having exactly the same issue.

Posted 3 months ago #

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