aw: Improve idle task scheduling

aw: Improve idle task scheduling

Three related changes:
* Only run idle tasks in the queue, not newly added ones.
* Move g_request_pending logic to SharedRendererState. This
  allows pending tasks to be cancelled correctly.
* Wait for kModeProcess to happen first before trying to
  request another to avoid a queue of pending tasks.

BUG=401712
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=288285

[boliu, 2014-08-07 22:12:39]

Ok, ready for review :D

[hush (inactive), 2014-08-07 22:14:27]

https://codereview.chromium.org/444173003/diff/60001/android_webview/browser/...
File android_webview/browser/shared_renderer_state.cc (right):

https://codereview.chromium.org/444173003/diff/60001/android_webview/browser/...
android_webview/browser/shared_renderer_state.cc:37: if (pending_ui_ ||
pending_non_ui_)
this means there should be only at most one pending request globally, at any
specific time. Right?

What happens if you one request pending on UI and another pending on non-UI
thread?

https://codereview.chromium.org/444173003/diff/60001/android_webview/browser/...
android_webview/browser/shared_renderer_state.cc:63: namespace {
an empty line after this line?

[boliu, 2014-08-07 22:21:35]

Newest is PS6 btw

https://codereview.chromium.org/444173003/diff/60001/android_webview/browser/...
File android_webview/browser/shared_renderer_state.cc (right):

https://codereview.chromium.org/444173003/diff/60001/android_webview/browser/...
android_webview/browser/shared_renderer_state.cc:37: if (pending_ui_ ||
pending_non_ui_)
On 2014/08/07 22:14:27, hush wrote:
> this means there should be only at most one pending request globally, at any
> specific time. Right?

That's the goal. But it's not quite true.

Right now there can be two RequestDrawGL calls before the first
DrawGL(kModeProcess) comes back. Here's how it happens:

Non-ui thread post UI thread to request gl, it runs.
UI thread request gl, it runs

But right now it's capped at just 2. This is good enough for now apparently.

> 
> What happens if you one request pending on UI and another pending on non-UI
> thread?

If UI comes first, it cancels the non-UI one. If the non-UI one comes first,
both goes through as above.

[hush (inactive), 2014-08-07 22:31:18]

https://codereview.chromium.org/444173003/diff/100001/android_webview/browser...
File android_webview/browser/shared_renderer_state.cc (right):

https://codereview.chromium.org/444173003/diff/100001/android_webview/browser...
android_webview/browser/shared_renderer_state.cc:130:
g_request_draw_gl_tracker.Get().DidDrawGLProcess();
Could you use a better name than "DidDrawGLProcess"? because it is called not
just when you get kModeProcess.

https://codereview.chromium.org/444173003/diff/100001/android_webview/native/...
File android_webview/native/aw_contents.cc (right):

https://codereview.chromium.org/444173003/diff/100001/android_webview/native/...
android_webview/native/aw_contents.cc:378: if (draw_info->mode ==
AwDrawGLInfo::kModeProcess) {
what happens if mode is AwDrawGLInfo::kModeProcessNoContext?

[hush (inactive), 2014-08-07 23:04:49]

https://codereview.chromium.org/444173003/diff/100001/android_webview/native/...
File android_webview/native/aw_contents.cc (right):

https://codereview.chromium.org/444173003/diff/100001/android_webview/native/...
android_webview/native/aw_contents.cc:366: draw_info->mode ==
AwDrawGLInfo::kModeProcessNoContext) {
we talked in persion. Our assumption is that kModeProcessNoContext should not
happen. Let's log an error here if it happens.

[boliu, 2014-08-07 23:28:08]

all done I think

https://codereview.chromium.org/444173003/diff/100001/android_webview/browser...
File android_webview/browser/shared_renderer_state.cc (right):

https://codereview.chromium.org/444173003/diff/100001/android_webview/browser...
android_webview/browser/shared_renderer_state.cc:130:
g_request_draw_gl_tracker.Get().DidDrawGLProcess();
On 2014/08/07 22:31:18, hush wrote:
> Could you use a better name than "DidDrawGLProcess"? because it is called not
> just when you get kModeProcess.

ResetPending?

[hush (inactive), 2014-08-07 23:39:44]

lgtm

https://codereview.chromium.org/444173003/diff/100001/android_webview/browser...
File android_webview/browser/shared_renderer_state.cc (right):

https://codereview.chromium.org/444173003/diff/100001/android_webview/browser...
android_webview/browser/shared_renderer_state.cc:130:
g_request_draw_gl_tracker.Get().DidDrawGLProcess();
sounds good.
On 2014/08/07 23:28:08, boliu wrote:
> On 2014/08/07 22:31:18, hush wrote:
> > Could you use a better name than "DidDrawGLProcess"? because it is called
not
> > just when you get kModeProcess.
> 
> ResetPending?

[boliu, 2014-08-07 23:42:46]

PS8 removed CurrentlyOnUIThread

[boliu, 2014-08-07 23:43:10]

The CQ bit was checked by boliu@chromium.org

[commit-bot: I haz the power, 2014-08-08 00:01:54]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/boliu@chromium.org/444173003/140001

[commit-bot: I haz the power, 2014-08-08 09:43:59]

Change committed as 288285