Support web workers in dart2js.

Support web workers in dart2js.
Committed: https://code.google.com/p/dart/source/detail?r=17078

[ngeoffray, 2013-01-15 12:04:06]

Lots of ad-hoc fixes to get Timers to work somehow OK with web workers. Let me
know what you think.

[kasperl, 2013-01-15 14:23:07]

LGTM.

[floitsch, 2013-01-15 14:25:17]

LGTM.

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart (right):

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart:254: int
numberOfTimers = 0;
I prefer activeTimerCount

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart:271: if
(numberOfTimers != 0) return false;
Add comment. For example:
if there is no active timer and no open receive ports we shut down the isolate.

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart:273:
_globalState.maybeCloseWorker();
From what I can see this is a single if check. It might easier to understand if
we inline the call.

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart:1314:
"Canceling a timer that needs to be in the internal event loop");
Timer in event loop cannot be canceled.
?

[ngeoffray, 2013-01-15 15:12:41]

Thanks Kasper and Florian.

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart (right):

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart:254: int
numberOfTimers = 0;
On 2013/01/15 14:25:17, floitsch wrote:
> I prefer activeTimerCount

Done.

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart:271: if
(numberOfTimers != 0) return false;
On 2013/01/15 14:25:17, floitsch wrote:
> Add comment. For example:
> if there is no active timer and no open receive ports we shut down the
isolate.

I added the comment in maybeCloseWorker.

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart:273:
_globalState.maybeCloseWorker();
On 2013/01/15 14:25:17, floitsch wrote:
> From what I can see this is a single if check. It might easier to understand
if
> we inline the call.

Done.

https://codereview.chromium.org/11864016/diff/4001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart:1314:
"Canceling a timer that needs to be in the internal event loop");
On 2013/01/15 14:25:17, floitsch wrote:
> Timer in event loop cannot be canceled.
> ?

Done.

[erikcorry, 2013-01-16 09:09:58]

https://codereview.chromium.org/11864016/diff/9001/sdk/lib/_internal/compiler...
File sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart (right):

https://codereview.chromium.org/11864016/diff/9001/sdk/lib/_internal/compiler...
sdk/lib/_internal/compiler/implementation/lib/isolate_helper.dart:274: &&
_globalState.isolates.containsKey(_globalState.rootContext.id)
Style guide prefers && at the end of a line so this edit seems gratuitous.