736643 - Add timestamp support to GC/CC JSON output

Status: VERIFIED FIXED

(Core :: JavaScript Engine, defect)

Description

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: patch

Pretty self-explanatory. I decided to have it pass in the time so that we can use PR_Now instead of PRMJ_Now. It looks like the implementations may be different, so I'd rather use the same one that the rest of the browser uses.

Comment 1

[Terrence Cole [:terrence]]

Comment on attachment 606782 [details] [diff] [review]
patch

Review of attachment 606782 [details] [diff] [review]:
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Looks fine.

Comment 2

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/31e8a3b6f4c3

Comment 3

[Henrik Skupin [:whimboo][⌚️UTC+1]]

So to calculate the beginning of the GC we would have to do timestamp-duration? Why do we want the timestamp for JSON only? Wouldn't it be helpful to have it in the console message too?

Comment 4

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

(In reply to Henrik Skupin (:whimboo) from comment #3)
> So to calculate the beginning of the GC we would have to do
> timestamp-duration?

Yes.

> Why do we want the timestamp for JSON only? Wouldn't it
> be helpful to have it in the console message too?

The console includes a kind of timestamp (the GC(T+x), where x is the time in seconds since the first GC). We used to include an actual timestamp, but it was just a random 16-digit number that wasn't useful to anyone. I guess we could put the time of day in there, but I don't think that would be helpful either. Usually the only thing we care about is how far apart the GCs are.

Comment 5

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/31e8a3b6f4c3

Comment 6

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Verified fixed with Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:14.0) Gecko/20120321 Firefox/14.0a1 ID:20120321031151

Just to note the timestamp is in microseconds so tools will have to convert it most likely into milliseconds first.