Create LibDispatchTaskRunner, a SingleThreadTaskRunner that is backed by a libdispatch queue.

Create LibDispatchTaskRunner, a SingleThreadTaskRunner that is backed by a libdispatch queue.

This task runner is meant to be used when an object needs to live on a single
thread but needs to both post tasks and receive callbacks via a dispatch queue.

BUG=158170
TEST=Covered by new unit test.


Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=171718

[Mark Mentovai, 2012-12-06 22:11:45]

LGTM

https://codereview.chromium.org/11464009/diff/1/base/mac/libdispatch_task_run...
File base/mac/libdispatch_task_runner.h (right):

https://codereview.chromium.org/11464009/diff/1/base/mac/libdispatch_task_run...
base/mac/libdispatch_task_runner.h:37: explicit LibDispatchTaskRunner(const
char* name);
Dunno if it’s totally useful to have callers supply their own name here. It’s
just used as a label. Is there a useful label that we could derive at runtime or
from some other object somehow?

https://codereview.chromium.org/11464009/diff/1/base/mac/libdispatch_task_run...
File base/mac/libdispatch_task_runner_unittest.cc (right):

https://codereview.chromium.org/11464009/diff/1/base/mac/libdispatch_task_run...
base/mac/libdispatch_task_runner_unittest.cc:32: void VerifyTaskOrder(const
char* expectations[], size_t num_expectations) {
I would make this conster, because I’d want the actual expectations later in the
file to be conster too. You will get better code that way.

https://codereview.chromium.org/11464009/diff/1/base/mac/libdispatch_task_run...
base/mac/libdispatch_task_runner_unittest.cc:178: const base::TimeDelta delta =
base::TimeDelta::FromMilliseconds(50);
These tests with timers are always so shady, but what can you do?

[Robert Sesek, 2012-12-06 22:18:05]

https://codereview.chromium.org/11464009/diff/1/base/mac/libdispatch_task_run...
File base/mac/libdispatch_task_runner.h (right):

https://codereview.chromium.org/11464009/diff/1/base/mac/libdispatch_task_run...
base/mac/libdispatch_task_runner.h:37: explicit LibDispatchTaskRunner(const
char* name);
On 2012/12/06 22:11:45, Mark Mentovai wrote:
> Dunno if it’s totally useful to have callers supply their own name here. It’s
> just used as a label. Is there a useful label that we could derive at runtime
or
> from some other object somehow?

No, callers should supply it like they do for well-established thread names.
E.g., this will be "Audio Thread" where I first use it.

https://codereview.chromium.org/11464009/diff/1/base/mac/libdispatch_task_run...
File base/mac/libdispatch_task_runner_unittest.cc (right):

https://codereview.chromium.org/11464009/diff/1/base/mac/libdispatch_task_run...
base/mac/libdispatch_task_runner_unittest.cc:32: void VerifyTaskOrder(const
char* expectations[], size_t num_expectations) {
On 2012/12/06 22:11:45, Mark Mentovai wrote:
> I would make this conster, because I’d want the actual expectations later in
the
> file to be conster too. You will get better code that way.

Done.

[Mark Mentovai, 2012-12-06 22:19:56]

LGTM

[commit-bot: I haz the power, 2012-12-06 22:23:36]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rsesek@chromium.org/11464009/8001

[commit-bot: I haz the power, 2012-12-06 23:54:31]

Sorry for I got bad news for ya.
Compile failed with a clobber build on mac.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac&number...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2012-12-07 00:06:46]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rsesek@chromium.org/11464009/3019

[commit-bot: I haz the power, 2012-12-07 07:47:19]

Change committed as 171718