When specifying a new create histogram callback, reset all histograms so they recreate themselves o…

When specifying a new create histogram callback, reset all histograms so they recreate themselves on next use.

We only do this for histograms, and not for counters, as counters might be used directly from generated code

BUG=none
TEST=none

Committed: https://code.google.com/p/v8/source/detail?r=12248

[jochen (gone - plz use gerrit), 2012-08-01 11:23:54]

plz review

[Michael Starzinger, 2012-08-01 11:41:06]

LGTM. I'll land that for you.

[Michael Starzinger, 2012-08-01 12:45:30]

https://chromiumcodereview.appspot.com/10828113/diff/3001/src/api.cc
File src/api.cc (right):

https://chromiumcodereview.appspot.com/10828113/diff/3001/src/api.cc#newcode5226
src/api.cc:5226: if (isolate->IsInitialized())
isolate->counters()->ResetHistograms();
I am not sure about this. There might be some weird case where the isolate
wasn't initialized but the counters have already been setup. It just feels
fragile.

Can we instead just call InitializeLoggingAndCounters() before resetting the
histograms (assuming that if someone calls SetCreateHistogramFunction on this
isolate he will actually initialize this isolate soonish)?

[jochen (gone - plz use gerrit), 2012-08-01 12:47:40]

https://chromiumcodereview.appspot.com/10828113/diff/3001/src/api.cc
File src/api.cc (right):

https://chromiumcodereview.appspot.com/10828113/diff/3001/src/api.cc#newcode5226
src/api.cc:5226: if (isolate->IsInitialized())
isolate->counters()->ResetHistograms();
On 2012/08/01 12:45:30, Michael Starzinger wrote:
> I am not sure about this. There might be some weird case where the isolate
> wasn't initialized but the counters have already been setup. It just feels
> fragile.
> 
> Can we instead just call InitializeLoggingAndCounters() before resetting the
> histograms (assuming that if someone calls SetCreateHistogramFunction on this
> isolate he will actually initialize this isolate soonish)?

Done.

[Michael Starzinger, 2012-08-01 12:48:07]

LGTM again. Will land ...