Introduce an API mirroring the gc extension

Introduce an API mirroring the gc extension

BUG=none
R=mstarzinger@chromium.org, svenpanne@chromium.org
LOG=y

Committed: https://code.google.com/p/v8/source/detail?r=18563

[jochen (gone - plz use gerrit), 2014-01-10 14:52:32]

plz review this one :)

[Benedikt Meurer, 2014-01-13 06:12:06]

https://codereview.chromium.org/131443008/diff/1/include/v8.h
File include/v8.h (right):

https://codereview.chromium.org/131443008/diff/1/include/v8.h#newcode4191
include/v8.h:4191: void RequestGarbageCollection(bool minor);
Please use an enum instead of bool here.

[jochen (gone - plz use gerrit), 2014-01-13 09:55:41]

On 2014/01/13 06:12:06, Benedikt Meurer wrote:
> https://codereview.chromium.org/131443008/diff/1/include/v8.h
> File include/v8.h (right):
> 
> https://codereview.chromium.org/131443008/diff/1/include/v8.h#newcode4191
> include/v8.h:4191: void RequestGarbageCollection(bool minor);
> Please use an enum instead of bool here.

done

[Michael Starzinger, 2014-01-13 10:13:24]

Hmpf.

https://codereview.chromium.org/131443008/diff/50001/include/v8.h
File include/v8.h (right):

https://codereview.chromium.org/131443008/diff/50001/include/v8.h#newcode4200
include/v8.h:4200: void RequestGarbageCollection(GarbageCollectionType type);
I don't like exposing this through the API at all. This should never be called
in production code. IIUC it is only used to replace the gc-extension for tests.

As discussed offline with Jochen: Using a "ForTesting" postfix in the name would
prevent that. I would strongly argue for renaming it in that way.

Also the comment needs to be adapted saying that this actually tanks performance
and only exists for testing purposes. I was thinking along the lines of ...

/**
 * Request garbage collection in this Isolate. If |minor| is true, a
 * minor garbage collection is performed.
 *
 * This should only be used for testing purposes and not to enforce a garbage
 * collection schedule. It has strong negative impact on the garbage collection
 * performance. Use IdleNotification() or LowMemoryNotification() instead to
 * influence the garbage collection schedule.
 */

(yes, at least four lines saying "don't use this")

[jochen (gone - plz use gerrit), 2014-01-13 10:30:27]

updated (and made it check that --expose_gc was passed)

[Michael Starzinger, 2014-01-13 10:53:34]

LGTM (what can possibly go wrong).

[jochen (gone - plz use gerrit), 2014-01-13 12:03:37]

Committed patchset #3 manually as r18563 (presubmit successful).