Develop Reference

safari 11 crashing when debugging on web inspector

Safari 11 is crashing when i open web inspector. Odd thing is, It works without failing if i don't open console panel. My HTML5 application works well in all other browsers.
There is no memory leaks as it is not going beyond 50MB while taking memory heaps. And no use of console methods.
Is this a known issue in Safari 11?

The only thing I can do to fix this is free up RAM. If I close a few applications and then try it again, it always works. Also after it crashes a few times you will not be able to inspect your device until you quit safari completely and open it again.

Some say it seems to be an hardware issue, happening only when the battery is at 100%.
Have a closer look here:
https://forums.developer.apple.com/thread/92290
Maybe it helps keeping on your flashlight and camera, then establishing a cable connection and starting the web inspector then.
Anyway: This wasn't working for me.
Another Maybe: Connect via network instead of a cable connection.
Things that might be too late by now:
Advice 1: Do not upgrade above 10.x and use Safari 10.x along with iOS 10.x
Advice 2: Put your devices in trash or sell it anyway and start not to use apple anymore. 99% of my upsets lead to issues with iOS and Mac.

What is released when restarting an iOS device?

SHORT QUESTION
I have a bug that only disappears when I restart my device. I would like to know what is released when restarting an iOS device in order to have an idea about what my bug is.
Releasing my cache and my RAM don't help to fix my bug, so I wonder what else could be released that fix my bug for a short time.
CONTEXT
I have a web app using WebGL and BabylonJS. It works really fine on all devices and all browsers except on iOS. With Safari, I always end by having the error message "A problem occurred with this web page so it was reloaded".
It happened on an iPad Air 2 (2Go RAM) running iOS 10.3.3 but I saw the same bug on every iOS device I could have in my hands. That's why I consider it as iOS only related.
I'm aware about iOS resource limits : https://stackoverflow.com/a/22193143/5053300
I tried to debug this for months, the bug appears randomly, sometimes quickly, sometimes slowly. There's nothing consistent so it's totally impossible to debug.
The best guess is that it's a memory issue because crashs seem to appear faster each time. And because the error message is quite always linked to memory issues.
I suspect textures and renderTargetTextures to take more and more memory (but I don't understand why it wouldn't be released, I don't keep useless references).
But there's something I'm sure : when I restart my device, it always work the first time (until I reload once, then begins the downward spiral).
If I clean my cache (via settings -> Safari) and my RAM (pressing home button when we are in shut down screen), the bug is still here. But if I restart my device, it disappears.
Something in memory is released and I would like to know what.
But I also could be totally wrong and it could be something else than memory, I'm open to all your suggestions.
Thanks in advance, it drives me crazy for months !
UPDATE
This is what JS Heap looks like :
UPDATE 2
A scene asking for 90 renderTargetTextures (379x890) each frame does work on iOS.
My app does work if I don't ask for any renderTargetTextures. But it crashes more or less quickly if I only ask for one small renderTargetTexture each frame.
What conclusions can I get from this observation ? Does it corroborate or deny the idea of a memory issue ?
UPDATE 3
There's no clue the following code really is the cause of the issue, but commenting/uncommenting it generaly makes disappear/appear the bug.
var texture = generateTexture();
function generateTexture() {
var rt1 = new BABYLON.RenderTargetTexture("rt1", { width: scene.getEngine().getRenderWidth(), height: scene.getEngine().getRenderHeight() }, scene, false, true, scene.getEngine().TEXTURETYPE_UNSIGNED_BYTE, false);
rt1.wrapU = BABYLON.Texture.CLAMP_ADDRESSMODE;
rt1.wrapV = BABYLON.Texture.CLAMP_ADDRESSMODE;
rt1.renderList.push(sphere);
rt1.onBeforeRender = function() {
sphere.material = std1;
};
scene.customRenderTargets.push(rt1);
return rt1;
}
I may insist on the fact that this code works in the link posted in update 2 so I don't think this code is relevant. The only thing is, commenting this part of the app seems to remove the random bug.
This code asks the 3D engine to render into one intermediary texture before to render to the screen. So this code impacts each frame.
In the link, I ask the engine to render into textures 90 times before to render to the screen.
UPDATE 4: PROBLEM SOLVED
The issue didn't depend on what is released on iOS restart, so I can't answer to my own question. But I can say that iOS doesn't like dynamic lighting.
From now on, all our projects will be limited to one light on iOS devices.
More lights, more computations each frame. It's too much for iOS that kills apps that ask for too much memory in a short time.

Without seeing your code I cannot guarantee any solution but I can offer some information about memory issues.
If you are sure that it never crashes on the first load, and it still crashes after clearing your device's memory, then it is unlikely to be a memory issue. That being said, if you are not sure of this, I would suggesting reading more about IOS memory usage. While the total memory for each device is known, the actual usable memory is much smaller. Furthermore, the memory shown in that post must be shared among all apps on the device, further limiting the memory availability.
I have found that even on a 2GB device, IOS will kill an app using ~200-300 MB of RAM because it was allocated too quickly. IOS takes both the amount and the speed of allocations into account when deciding whether or not to kill an app. Since each tab in Safari runs separately, it is likely that the same mechanism is at work. It is possible that your web app loads so much data into RAM so quickly that IOS refuses to carry out the request.
I would recommend reconsidering your assumptions about memory usage and profiling the app again after reading about the true memory limits of IOS. While it may not solve the issue, it will at least confirm whether memory is the issue.

Chrome Dev Tools very slow to respond in large web app

I have a large, javascript heavy web app that I am working on. I am experiencing very slow response times from Chrome Dev Tools for XHR responses and console loggging (3-5 secs). The actual app is running fast and responsive, only dev tools looks like it is suffering.
Does anyone have any idea why Chrome Dev Tools is becoming sluggish as my app grows?

Devtools are like any other debugger; they hook into the normal processing flow of an application, and store quite a bit more information than is normally required. This is much more work than simply rendering the page without debugging enabled, so it will indeed be slower.
That said, 3 seconds to respond to console.log seems high. I'd suggest that you first test the application in a nightly version of WebKit. If it's responsive in WebKit, but not in Chrome, please file a bug against the inspector via http://new.crbug.com/ along with any information you can provide about what scenario causes the slowness.
If it's equally sluggish in WebKit, please file a bug against WebKit's Inspector component: https://bugs.webkit.org/enter_bug.cgi
Either way, post the bug ID here, and I'll see that it's triaged into the correct team.

I "fixed" the slow chrome developer tool by (under SOURCES tab)
clearing the "watch" list that accumulated over time...
clearing all the "snippets", i had dozens as well...
Not sure which of both made the most difference, but it certainly made a difference

This is an old question, but it may help someone landing here later like I did.
Using Chrome 46.x/47.x on Linux (RHEL 7), none of the proposed solutions worked for me. What did work was to disable the setting "Use hardware acceleration when available", in the advanced browser settings.
I noticed in the process monitor/list that the Chrome renderer was taking up a lot of CPU, even putting a breakpoint or stepping throught statements in the debugger would take 10+ seconds!
Might be worth a shot.

Undock the developer tools into separate window.
In my case, it's work.

I struggled with this also, to the point where stepping through code using the chrome debugger was just so slow it took hours away from my productive development time. In watching the CPU utilization when debugging in chrome I would see it use up to as much at 40% of all 4 cores of my processor. I tried everything to no avail. Finally, I tried making the browser window of the page I was debugging as small as I could without losing any of the required view and miraculously it solved the problem. So, now I keep my debugger window popped out in a separate window, and make the window of the page I am debugging as small as I can and my debugging experience is very fast again. I have tested this over a period of weeks and it has held out. Hope this helps someone.

browser (javascript) resource problems

I've lately been running into odd issues, which I'm starting to think are related to resource starvation in the browser.
In FF:
I'd been testing one of our web apps and suddenly things that should disappear after a couple seconds stopped disappearing. I tracked back to setTimeout just flat out refusing to work. After reloading the browser it was all clear, no issues.
In IE:
I regularly see issues where IE will refuse to do transparency all the sudden, simply reloading the page clears this up.
In both:
Though I can't say its related for sure, I see unexplainable behavior, things along the lines of variables not being available (undefined) when they should be.
Both browsers also show a steady increase in memory usage over time (memory leaks).
The javascript in the web app is heavy and it is a single load page (making those memory issues mentioned all the more painful). There are lots of in-efficiency, and various things that make one say "why would you do that?".
Has anyone encountered such things? Can you point out general resources that will help identify and resolve these issues?

You could try running your application against the Chrome Profiler http://code.google.com/chrome/devtools/docs/overview.html. You can profile the CPU and get snapshots of the browser heap, that should help locate any rogue stuff.

If your application is designed to work with the Internet Explorer: The Developer Toolbar also has a profiler.

Website spontaneously freezes in Chrome - how to debug?

I build this
http://ipl.janstudt.de/
website which is supposed to run on the iPad (it does) and in Google Chrome. In Chrome (on Win 7 64bit), after a seemingly random time of a few minutes, the browser freezes. Also, sometimes when I click the "Reload Page" button in Chrome while on this site, the Browser also freezes. In both cases, the Browser recovers after 10-20 seconds.
How do I get to the bottom of this? There are no Javascript Errors. The memory footprint is very modest and does not increase over time (according to the heap snapshots). There are no plugins involved.

I really doubt it is your script; rather, I think it is Chrome doing something silly. I would test it on other similar systems to see if you can reproduce it. I've had it running on mine for about 5 minutes with no issues (Win7, 64bit, Chrome 5.0.375.127).
You could try to keep the profiler running and catch the freeze-up, but I think that would just be a waste of time.

Landed here while dealing with similar issue. Got a solution by changing hardware acceleration settings
FYI:
https://productforums.google.com/d/msg/chrome/daV0DhOXKVI/oBPZ6pUtBgAJ