[IndexedDB] Added IndexedDBCursor lifetime tracing

[IndexedDB] Added IndexedDBCursor lifetime tracing

IndexedDBCursor creation can currently cause OOM's in the browser.
Adding lifetime tracing so that this situation is visible.

R=cmumford
BUG=690517
Review-Url: https://codereview.chromium.org/2745703002
Cr-Commit-Position: refs/heads/master@{#460608}
Committed: https://chromium.googlesource.com/chromium/src/+/84f5e2800a49ce3de9f877ea842b104d0484bd52

[dmurph, 2017-03-10 01:16:29]

Chris, can you PTAL? Super small patch, adding IDBCursor lifetime tracing.

[cmumford, 2017-03-13 14:22:33]

lgtm

[dmurph, 2017-03-13 22:35:53]

The CQ bit was checked by dmurph@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-13 22:36:46]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[dmurph, 2017-03-13 22:36:52]

On 2017/03/13 14:22:33, cmumford wrote:
> lgtm

FYI - I changed this slightly, as this object is still modeled after the
lifetime in the JS. Now it records the end of lifetime on 'close'.

[commit-bot: I haz the power, 2017-03-13 23:35:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-13 23:35:52]

Dry run: This issue passed the CQ dry run.

[cmumford, 2017-03-14 16:30:56]

https://codereview.chromium.org/2745703002/diff/20001/content/browser/indexed...
File content/browser/indexed_db/indexed_db_cursor.cc (right):

https://codereview.chromium.org/2745703002/diff/20001/content/browser/indexed...
content/browser/indexed_db/indexed_db_cursor.cc:73: if (!closed_) {
Nit: How about Having ::Close() to a:

  if (closed_)
    return;

and then remove the check from the destructor. C++ call tail optimization should
make it equally efficient.

https://codereview.chromium.org/2745703002/diff/20001/content/browser/indexed...
content/browser/indexed_db/indexed_db_cursor.cc:278:
IDB_ASYNC_TRACE_END("IndexedDBCursor::lifetime", this);
::lifetime is better called from the destructor since there's no guarantee how
long the owner may hold on to a cursor after it is closed. I realize that it's
the end of it's "effective" lifetime, but since the object still "lives" on, the
name or call site seem out of place.

[dmurph, 2017-03-29 23:02:17]

The CQ bit was checked by dmurph@chromium.org to run a CQ dry run

[dmurph, 2017-03-29 23:02:19]

https://codereview.chromium.org/2745703002/diff/20001/content/browser/indexed...
File content/browser/indexed_db/indexed_db_cursor.cc (right):

https://codereview.chromium.org/2745703002/diff/20001/content/browser/indexed...
content/browser/indexed_db/indexed_db_cursor.cc:73: if (!closed_) {
On 2017/03/14 16:30:56, cmumford wrote:
> Nit: How about Having ::Close() to a:
> 
>   if (closed_)
>     return;
> 
> and then remove the check from the destructor. C++ call tail optimization
should
> make it equally efficient.

Done.

https://codereview.chromium.org/2745703002/diff/20001/content/browser/indexed...
content/browser/indexed_db/indexed_db_cursor.cc:278:
IDB_ASYNC_TRACE_END("IndexedDBCursor::lifetime", this);
On 2017/03/14 16:30:56, cmumford wrote:
> ::lifetime is better called from the destructor since there's no guarantee how
> long the owner may hold on to a cursor after it is closed. I realize that it's
> the end of it's "effective" lifetime, but since the object still "lives" on,
the
> name or call site seem out of place.

Changed to ::open

[dmurph, 2017-03-29 23:02:57]

I'm going to go ahead and submit (cl queue is pretty big), let me know if I
should change anything in a follow up cl

[dmurph, 2017-03-29 23:03:02]

The CQ bit was unchecked by dmurph@chromium.org

[dmurph, 2017-03-29 23:03:05]

The CQ bit was checked by dmurph@chromium.org

[dmurph, 2017-03-29 23:03:05]

The patchset sent to the CQ was uploaded after l-g-t-m from
cmumford@chromium.org
Link to the patchset: https://codereview.chromium.org/2745703002/#ps60001
(title: "comments")

[commit-bot: I haz the power, 2017-03-29 23:03:13]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-30 00:59:00]

CQ is committing da patch.

Bot data: {"patchset_id": 60001, "attempt_start_ts": 1490828585097750,
"parent_rev": "d6dbb26e31818eed0097654ecb89aaddc2c64f8d", "commit_rev":
"84f5e2800a49ce3de9f877ea842b104d0484bd52"}

[commit-bot: I haz the power, 2017-03-30 00:59:44]

Description was changed from

==========
[IndexedDB] Added IndexedDBCursor lifetime tracing

IndexedDBCursor creation can currently cause OOM's in the browser.
Adding lifetime tracing so that this situation is visible.

R=cmumford
BUG=690517
==========

to

==========
[IndexedDB] Added IndexedDBCursor lifetime tracing

IndexedDBCursor creation can currently cause OOM's in the browser.
Adding lifetime tracing so that this situation is visible.

R=cmumford
BUG=690517

Review-Url: https://codereview.chromium.org/2745703002
Cr-Commit-Position: refs/heads/master@{#460608}
Committed:
https://chromium.googlesource.com/chromium/src/+/84f5e2800a49ce3de9f877ea842b...
==========

[commit-bot: I haz the power, 2017-03-30 00:59:45]

Committed patchset #4 (id:60001) as
https://chromium.googlesource.com/chromium/src/+/84f5e2800a49ce3de9f877ea842b...