Bug 26418 – Profiler 'Call' count is incorrect in Heavy view

• Status: RESOLVED
• Resolution: INVALID
• Component: Web Inspector (Deprecated)

[Kevin McCullough]

6/12/09 12:09 PM Kevin McCullough:
* SUMMARY
In Heavy view callers have the same number of calls as their root, or called, functions.  This is not correct and does not show up in the Tree view.

* STEPS TO REPRODUCE
1. Load the attached test page in Safari
2. Start the profiler
3. Click the run-test button
4. Stop the profiler
5. Look at the heavy and tree views and see how the number of calls assigned to callers is different (e.g. 'runTest' was only called once, but in heavy view it says it was called 3 times

<rdar://problem/6968125>

It turns out that call, self and total time are all incorrect for callers in Heavy View

[Kevin McCullough]

Created attachment 31307 [details]
Test

[Kevin McCullough]

Created attachment 31312 [details]
Screenshot of error

Notice that 'runTest' is listed 3 times in heavy view but all three show different %s and times.

[Kevin McCullough]

Created attachment 31313 [details]
proposed patch

[Timothy Hatcher]

Can you post a screenshot of the new behaviour?

[Kevin McCullough]

Created attachment 31314 [details]
Correct behavior

[Kevin McCullough]

Committed revision 44697.

[Francisco Tolmasky]

The original behavior was correct. The calls are supposed to be different than tree view. There is an in depth explanation as to what they mean here: http://www.alertdebugging.com/2009/04/29/building-a-better-javascript-profiler-with-webkit/

The purpose of the calls/percentages/etc is to show a reverse backtrace not to simply "flip tree view on its head".

The way to read the original profile, showing "3" in all three columns, is as follows: "three calls to log to place from runTest", NOT "three runTests resulted in 3 logs". Had you had multiple functions calling "console.log" you would see how they break down. This is how it works in Shark, and the purpose is to be able to identify where most of the "offending" calls are coming from. Again, if you like I can list this here but the link above does a good job of explaining it. 

[Francisco Tolmasky]

Sorry, that should read  "three calls to log took place from runTest"

(In reply to comment #7)
> The original behavior was correct. The calls are supposed to be different than
> tree view. There is an in depth explanation as to what they mean here:
> http://www.alertdebugging.com/2009/04/29/building-a-better-javascript-profiler-with-webkit/
> 
> The purpose of the calls/percentages/etc is to show a reverse backtrace not to
> simply "flip tree view on its head".
> 
> The way to read the original profile, showing "3" in all three columns, is as
> follows: "three calls to log to place from runTest", NOT "three runTests
> resulted in 3 logs". Had you had multiple functions calling "console.log" you
> would see how they break down. This is how it works in Shark, and the purpose
> is to be able to identify where most of the "offending" calls are coming from.
> Again, if you like I can list this here but the link above does a good job of
> explaining it. 
> 

[Adam Roben (:aroben)]

Comment on attachment 31313 [details]
proposed patch

> +        <rdar://problem/6968125> Profiler 'Call' count is incorrect in Heavy
> +        view (26418)

We normally include the Bugzilla URLs in the ChangeLog, as well.

[Mark Rowe (bdash)]

Reopening as this was rolled out due to being incorrect.

[Mark Rowe (bdash)]

It was rolled out in: <http://trac.webkit.org/changeset/44698>.  Closing as INVALID to reflect that the behavior was correct.