Bug 86568 – Add instrumentation to Vector to track used capacity, and dump useful info

• Status: NEW
• Component: Web Template Framework

[Simon Fraser (smfr)]

Add instrumentation to Vector to track used capacity, and dump useful info

[Simon Fraser (smfr)]

Created attachment 142141 [details]
Patch

[WebKit Review Bot]

Attachment 142141 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WTF/ChangeLog', u'Source/WTF/WTF.xc..." exit_code: 1
Source/WTF/wtf/Vector.h:43:  Code inside a namespace should not be indented.  [whitespace/indent] [4]
Total errors found: 1 in 4 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Brent Fulgham]

Comment on attachment 142141 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=142141&action=review

The whole patch should probably have been landed long ago; it probably doesn't impact non-Mac platforms at all. We're there particular cases where these statistics were helpful in debugging a problem that you can mention?

R=me.

> Source/WTF/wtf/Vector.cpp:56
> +    pthread_once(&initializeOnceKey, initializeOnce);

Should we have a FIXME here for other platforms?

> Source/WTF/wtf/Vector.cpp:125
> +    VectorHash::iterator it = vectorData.find(vector);

It might be clearer to handle the fail/log case as an early return here.

> Source/WTF/wtf/Vector.cpp:142
> +    long long m_totalSizeBytes; 

Would it be better to use something like int64_t? Actually, does it make sense to allow these to be signed? Maybe uint64_t would be better?

[Julien Chaffraix]

Comment on attachment 142141 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=142141&action=review

Simon, it seems that this code will be dead the moment it lands as it requires some modification of the main even loop that no port implements. Is there a plan to add this tracking to any platform or even better DRT?

> Source/WTF/wtf/Vector.cpp:42
> +#if OS(DARWIN)

It's wrong to use OS(DARWIN) here, you should use USE(PTHREADS)

> Source/WTF/wtf/Vector.cpp:88
> +    }

Regular WebKit style puts the functions first and the members last.

[Simon Fraser (smfr)]

Someone is welcome to take this patch and fix it up so that it works for all ports. I'm unlikely to do that any time soon.

[Eric Seidel (no email)]

Attachment 142141 [details] was posted by a committer and has review+, assigning to Simon Fraser for commit.