Fix two races in DirectoryWatcherInotify:

Fix two races in DirectoryWatcherInotify:

1. In DirectoryWatcherImpl::Watch we have to initialize delegate_, root_path_
   and other members before calling InotifyReader::AddWatch, because otherwise
   the following race is possible:

   1. InotifyReader::AddWatch
   2. DirectoryWatcherImpl::OnInotifyEvent, where we want to use delegate_
      and root_path_
   3. Now-late initialization of delegate_ and root_path_ in DirectoryWatcherImpl::Watch

2. In InotifyReader::OnInotifyEvent we can't just copy things under a lock
   and notify without a lock. Otherwise the following race is possible:

   1. Things get copied in InotifyReader::OnInotifyEvent, lock is released
   2. DirectoryWatcherImpl is destroyed, removing its watch
   3. But it's still in the copied set of watchers to be notified. When we get
      to notifying it, it's invalid, and we have a crash.

To fix race #2, I decided to just do everything under the lock. Notifications
shouldn't be a bottleneck, and I don't want to prematurely add more complexity.

TEST=Manually with RaceChecker, see bug.
http://crbug.com/15473

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=20730

[Paweł Hajdan Jr., 2009-07-14 20:36:56]

Please review:

Evan: the code.
Aaron: do you have any objections about doing all notifications under the lock?
For now the primary user of DirectoryWatcher is extension system.

timurrrr: Thanks for catching the issues. Could you verify that they are gone
after applying this patch?

[Evan Martin, 2009-07-14 20:39:01]

LGTM

[Aaron Boodman, 2009-07-14 21:22:30]

LGTM

On Tue, Jul 14, 2009 at 1:39 PM, <evan@chromium.org> wrote:
> LGTM
>
> http://codereview.chromium.org/149630
>

[the_wrong_timurrrr, 2009-07-15 09:14:01]

On 2009/07/14 20:36:56, Paweł Hajdan Jr. wrote:
> Please review:
> 
> Evan: the code.
> Aaron: do you have any objections about doing all notifications under the
lock?
> For now the primary user of DirectoryWatcher is extension system.
> 
> timurrrr: Thanks for catching the issues. Could you verify that they are gone
> after applying this patch?
LGTM