Pyauto remote inspector module now provides garbage collect functionality.

Pyauto remote inspector module now provides garbage collect functionality.

Previously, the pyauto remote inspector module only allowed a test to take
a v8 heap snapshot, as follows:

import perf_snapshot
snapshotter = perf_snapshot.PerformanceSnapshotter()
snapshot = snapshotter.HeapSnapshot()

With this change, the same object now provides the GarbageCollect() function,
which forces a garbage collection:

import perf_snapshot
snapshotter = perf_snapshot.PerformanceSnapshotter()
snapshot = snapshotter.GarbageCollect()

Refactoring of perf_snapshot.py still needs to be done to make it more
general (useful for various kinds of interaction with the remote inspector).
This CL includes a portion of this refactoring: I separated the
_PerformanceSnapshotterThread class into 2 classes: a base class called
_RemoteInspectorBaseThread, and a subclass called
_PerformanceSnapshotterThread.  There is a new subclass called
_GarbageCollectThread to implement the garbage collection functionality.

In a future CL, I intend to do some additional refactoring of comments
and organization of the code, and also change the name of the file itself.

BUG=chromium-os:23962
TEST=None

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=114510

[Nirnimesh, 2011-12-13 21:21:59]

LGTM

http://codereview.chromium.org/8885025/diff/1/chrome/test/pyautolib/perf_snap...
File chrome/test/pyautolib/perf_snapshot.py (right):

http://codereview.chromium.org/8885025/diff/1/chrome/test/pyautolib/perf_snap...
chrome/test/pyautolib/perf_snapshot.py:255: self._lock = threading.Lock()
use a better var name.

http://codereview.chromium.org/8885025/diff/1/chrome/test/pyautolib/perf_snap...
chrome/test/pyautolib/perf_snapshot.py:417: """Initializes a
_RemoteInspectorBaseThread object.
Keep it short: Initialize.

http://codereview.chromium.org/8885025/diff/1/chrome/test/pyautolib/perf_snap...
chrome/test/pyautolib/perf_snapshot.py:422: verbose: A boolean indicating
whether or not to use verbose logging.
In future this should probably re-use pyauto's verbose flag.

[dennis_jeffrey, 2011-12-14 22:38:48]

Thanks!  I synced with tip-of-tree, addressed the comments, and added one more
statement to the run() method in the _GarbageCollectThread class:

self._client.close()

I had forgotten to add that before, and it causes a problem if you force a
garbage collect and then later try to take a heap snapshot (in this case, the
module fails to connect to the remote chrome instance the next time you try to
do so).  Adding that one statement fixes the problem.

I'm going to submit this CL now.

http://codereview.chromium.org/8885025/diff/1/chrome/test/pyautolib/perf_snap...
File chrome/test/pyautolib/perf_snapshot.py (right):

http://codereview.chromium.org/8885025/diff/1/chrome/test/pyautolib/perf_snap...
chrome/test/pyautolib/perf_snapshot.py:255: self._lock = threading.Lock()
On 2011/12/13 21:21:59, Nirnimesh wrote:
> use a better var name.

Done.

http://codereview.chromium.org/8885025/diff/1/chrome/test/pyautolib/perf_snap...
chrome/test/pyautolib/perf_snapshot.py:417: """Initializes a
_RemoteInspectorBaseThread object.
On 2011/12/13 21:21:59, Nirnimesh wrote:
> Keep it short: Initialize.

Done - I made the same change where applicable elsewhere too.

http://codereview.chromium.org/8885025/diff/1/chrome/test/pyautolib/perf_snap...
chrome/test/pyautolib/perf_snapshot.py:422: verbose: A boolean indicating
whether or not to use verbose logging.
On 2011/12/13 21:21:59, Nirnimesh wrote:
> In future this should probably re-use pyauto's verbose flag.

Good point - I added a TODO for that.