Bug 39825

Summary:

Memory retention using timers (when viewing inspector timeline)

Product:

WebKit

Reporter:

Christopher Hunt <huntc>

Component:

Web Inspector (Deprecated)

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED FIXED

Severity:

Major

CC:

ap, burg, ggaren, jchaffraix, mark.lam, simon.fraser

Priority:

Version:

528+ (Nightly build)

Hardware:

Mac (Intel)

OS:

OS X 10.6

Attachments:

Description	Flags
Screen shot of memory consumption	none
Screen shot of memory profile using Instruments	none
Sample HTML file to reproduce the issue	none

Christopher Hunt

Reported 2010-05-27 03:48:44 PDT

Created attachment 57216 [details] Screen shot of memory consumption I'm wondering if there's a memory retention issue given the use of timers. Here's some html: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html> <head> <title>Timer Memory Retention</title> </head> <body> <p>Please observe memory usage with the timeline profiler.</p> <script type="text/javascript"> setInterval(null, 100); </script> </body> </html> What we have is a script that simply sets up a timer to execute every 100ms. It makes no difference to the test whether a function is called on the timer firing. If you load this and then use the timeline profile then you should observe memory continue to be consumed. Within a couple of minutes memory usage doubles. I have had this running for several minutes with no apparent reduction in the rate of memory consumed. I have attached a screenshot of the memory consumption timeline.

Attachments
Screen shot of memory consumption (150.16 KB, image/png) 2010-05-27 03:48 PDT, Christopher Hunt	no flags	Details
Screen shot of memory profile using Instruments (137.24 KB, image/png) 2010-06-01 21:36 PDT, Christopher Hunt	no flags	Details
Sample HTML file to reproduce the issue (370 bytes, text/html) 2010-07-24 15:41 PDT, Christopher Hunt	no flags	Details
View All Add attachment proposed patch, testcase, etc.

Simon Fraser (smfr)

Comment 1 2010-05-27 18:26:13 PDT

I hope the timeline profiler excludes memory use by the inspector itself.

Geoffrey Garen

Comment 2 2010-05-27 23:46:07 PDT

(In reply to comment #1) > I hope the timeline profiler excludes memory use by the inspector itself. It doesn't. That could be the issue.

Christopher Hunt

Comment 3 2010-05-28 01:03:18 PDT

Hi Geoff. Do you have a feel for whether this issue is easily resolved?

Geoffrey Garen

Comment 4 2010-05-28 10:07:41 PDT

(In reply to comment #3) > Hi Geoff. Do you have a feel for whether this issue is easily resolved? If the Web Inspector guess is true, it's not easily resolved. We would need to move the Web Inspector to use a separate heap/JSGlobalData. Doable, but nontrivial.

Christopher Hunt

Comment 5 2010-06-01 19:50:41 PDT

I've now downloaded WebKit and built it. I'd be happy to have a go at fixing this issue if someone can point me in the right direction. I have a memory retention issue in my application in production and I simply must nail down what is causing it so I'm keen to help!

Simon Fraser (smfr)

Comment 6 2010-06-01 20:33:43 PDT

> I have a memory retention issue in my application in production Is this on Mac OS X? Have you tried the simple stuff, like running 'leaks'?

Christopher Hunt

Comment 7 2010-06-01 20:40:35 PDT

(In reply to comment #6) > Is this on Mac OS X? Have you tried the simple stuff, like running 'leaks'? I confess to not having tried leaks - I've not been regarding the problem as a memory leak; more of a retention issue within Javascript. I shall of course try this, though I'd still like to help with this particular issue. It seems to me that the memory profiler being introduced is de-valued if there is a fundamental issue in its consideration of gathering metrics.

Christopher Hunt

Comment 8 2010-06-01 21:34:58 PDT

(In reply to comment #7) I just profiled the app using leaks as part of Instruments under OS X. What I found was that WebKit/Safari does *not* appear to be leaking memory adding strength to the view that the memory profiler of WebKit is not considering its own object allocations in its output. I attach the Instruments view over several minutes of running WebKit/Safari (debug build). Any ideas then on where I should start looking in the WebKit code with a view to helping fix the memory profiler part of the Web Inspector?

Christopher Hunt

Comment 9 2010-06-01 21:36:04 PDT

Created attachment 57619 [details] Screen shot of memory profile using Instruments

Christopher Hunt

Comment 10 2010-06-08 04:56:37 PDT

Anyone out there care to point me toward some doco that gives an introduction to the Web Inspector architecture, or better still a hint on where to start looking? I would have thought they'd be some interest in getting this problem resolved...

Christopher Hunt

Comment 11 2010-07-24 15:41:34 PDT

Created attachment 62510 [details] Sample HTML file to reproduce the issue Attached an HTML/JS file that easily illustrates the problem.

Christopher Hunt

Comment 12 2012-07-08 00:33:45 PDT

Still a problem with Lion, and also occurs with the Canary build of Chrome. Any interest at all out there?

Brian Burg

Comment 13 2014-12-04 16:03:42 PST

This should be resolved now that Inspector runs in its own process. Please re-open or file new bug if you feel that's not the case.

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