On 27/06/2012 2:35 AM, Alan Bateman wrote:
On 25/06/2012 05:26, David Holmes wrote:
webrev:
http://cr.openjdk.java.net/~dholmes/7161229/webrev/
When removing the last element from the PBQ the "sift down" logic
would store it back in as array[0]. The simple fix is for the
sift-down to be a no-op if the queue size is zero.
The fix has been contributed by Doug Lea. We are taking this
opportunity to synchronize PBQ with Doug's latest version at:
http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/main/java/util/concurrent/PriorityBlockingQueue.java?view=log
So in addition to the above functional fix there are a number of
miscellaneous code and comment cleanups. The only non-trivial, but
still very simple, change is to the drainTo method to make it more
robust if the add() on the destination collection throws an exception.
I am of course a Reviewer for this.
I have provided the update to the LastElement test (as this is
certainly related to the last element) but there are some reservations
about examining the PBS internals this way. Unfortunately there is no
good way to test for these kinds of retention issues. You either need
a whitebox test like this, or need to rely on non-guaranteed GC and
finalization behaviour.
I looked through the changes to siftDown* and the other clean-ups and
they look fine to me.
Thanks Alan.
As this test doesn't set a security manager then I assume it doesn't
really need L92-94.
The IllegalAccessException has to be caught as it is a checked exception
from getDeclaredField(). I removed the AccessControlException though.
It is a bit icky to use reflection and pull out a
private field but I don't think it's is easily tested otherwise.
The only other way is resorting to gc/finalization hacks - and that is
even more icky in my opinion. If the field vanishes one day the test
will fail and we'll know to update it.
I've updated the webrev for reference:
http://cr.openjdk.java.net/~dholmes/7161229/webrev.01/
but will go ahead with the push.
Thanks,
David
-Alan,
