Initialize the frequeny once and use it, avoid calling a native method every

Initialize the frequeny once and use it, avoid calling a native method every
time the frequency is needed.

R=kasperl@google.com, sgjesse@google.com, zra@google.com

Committed: https://code.google.com/p/dart/source/detail?r=32659

[zra, 2014-02-12 00:20:34]

lgtm

[Søren Gjesse, 2014-02-12 07:36:10]

lgtm

[kasperl, 2014-02-12 07:43:26]

Does *not* look good to me.

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart
File sdk/lib/core/stopwatch.dart (right):

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart#...
sdk/lib/core/stopwatch.dart:14: int frequency;
This needs to be final. Otherwise, you're in trouble.

[kasperl, 2014-02-12 07:44:16]

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart
File sdk/lib/core/stopwatch.dart (right):

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart#...
sdk/lib/core/stopwatch.dart:14: int frequency;
On 2014/02/12 07:43:26, kasperl wrote:
> This needs to be final. Otherwise, you're in trouble.

You can also initialize this at the declaration site (same goes for _start and
_stop which actually do not need initialization).

[kasperl, 2014-02-12 07:57:02]

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart
File sdk/lib/core/stopwatch.dart (right):

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart#...
sdk/lib/core/stopwatch.dart:130: external static int _frequency();
You could also use a lazily initialized static field to only ever get one call
to the native. Maybe that's overkill.

[siva, 2014-02-13 01:16:50]

PTAL.

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart
File sdk/lib/core/stopwatch.dart (right):

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart#...
sdk/lib/core/stopwatch.dart:14: int frequency;
On 2014/02/12 07:43:26, kasperl wrote:
> This needs to be final. Otherwise, you're in trouble.

Good catch, need to get used to Dart programming.

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart#...
sdk/lib/core/stopwatch.dart:14: int frequency;
On 2014/02/12 07:44:16, kasperl wrote:
> On 2014/02/12 07:43:26, kasperl wrote:
> > This needs to be final. Otherwise, you're in trouble.
> 
> You can also initialize this at the declaration site (same goes for _start and
> _stop which actually do not need initialization).

Done.

https://codereview.chromium.org/154263010/diff/1/sdk/lib/core/stopwatch.dart#...
sdk/lib/core/stopwatch.dart:130: external static int _frequency();
Will do this later if needed.

On 2014/02/12 07:57:03, kasperl wrote:
> You could also use a lazily initialized static field to only ever get one call
> to the native. Maybe that's overkill.

[kasperl, 2014-02-13 06:17:09]

LGTM!

https://codereview.chromium.org/154263010/diff/120001/sdk/lib/core/stopwatch....
File sdk/lib/core/stopwatch.dart (right):

https://codereview.chromium.org/154263010/diff/120001/sdk/lib/core/stopwatch....
sdk/lib/core/stopwatch.dart:32: Stopwatch() {}
No need for the {}. You can replace that with ;. 

  Stopwatch();

You can even get rid of the whole constructor now, but I'd probably keep it as a
place-holder for the doc comment.

[siva, 2014-02-13 17:06:39]

https://codereview.chromium.org/154263010/diff/120001/sdk/lib/core/stopwatch....
File sdk/lib/core/stopwatch.dart (right):

https://codereview.chromium.org/154263010/diff/120001/sdk/lib/core/stopwatch....
sdk/lib/core/stopwatch.dart:32: Stopwatch() {}
On 2014/02/13 06:17:09, kasperl wrote:
> No need for the {}. You can replace that with ;. 
> 
>   Stopwatch();
> 
> You can even get rid of the whole constructor now, but I'd probably keep it as
a
> place-holder for the doc comment.

Done.

[siva, 2014-02-13 17:06:52]

Committed patchset #5 manually as r32659 (presubmit successful).