7191467: (fs) WatchService periodically fails to queue ENTRY_DELETE event for short lived file [sol11]

[Chris Hegarty]

The change looks ok to me.

-Chris.

On 15/08/12 12:20, Alan Bateman wrote:
>
> MayFlies is one of the tests for the WatchService, it's a stress test
> that ensures that there are corresponding ENTRY_DELETE events for each
> ENTRY_CREATE event when the files are very short lived. This test fails
> periodically on Solaris 11 where it appears that FILE_REMOVE events
> aren't being queued by the kernel. There are a couple of workarounds in
> this code to deal with a kernel issues in this area and I've decided it
> to be best to just remove these and change the implementation so that it
> detects file deletions when scanning the directory (which it has to do
> anyway when the directory changes).
>
> The webrev with the changes is here:
>
> http://cr.openjdk.java.net/~alanb/7191467/webrev/
>
> The main change is that entries in directories are only registered with
> the kernel when the directory is registered for ENTRY_MODIFY events.
> ENTRY_CREATE and ENTRY_DELETE events are now completely triggered on
> changes to the directory.
>
> One other change in here, and it stemmed from a discussion on this mail
> a few months ago, is that if there is an error encountered when
> iterating over the directory then an OVERFLOW event is queued. That is
> the trigger to the user application to re-scan the directory to update
> its view of the directory.
>
> -Alan