On 26/03/15 14:43, Peter Levart wrote:
On 03/26/2015 01:28 PM, David Holmes wrote:
Hi Daniel,
On 26/03/2015 10:08 PM, Daniel Fuchs wrote:
Please find below a trivial fix for
7113878: LogManager - namedLoggers should be ConcurrentHashMap
instead of Hashtable
As you say in the bug report, now that the map is always accessed
within synchronized code this serves no purpose. The map not only
doesn't need to be concurrent, it doesn't even need to be thread-safe!
So why not replace with a simple HashMap?
David
Hi Daniel,
...or, if you keep CHM, you might be able to use it for a benefit.
You say that retrieving a logger by name is the most frequent operation.
If you can prove that moving a statement in addLocalLogger method that
publishes the Logger via CHM to the end of synchronized block without
hurting the logic that exists in-between and initializes the Logger
instance, then you can implement the findLogger method in a way that
almost never needs to enter synchronized block:
http://cr.openjdk.java.net/~plevart/jdk9-dev/LogManager.CHM/webrev.01/
Right. I was also thinking that there may be a way to
use computeIfAbsent to rewrite some of the old logic - but I'd
rather do that in a separate change set.
This is partly why I didn't want to go much more beyond
the simple switch here. I'll keep your idea above in mind though.
Synchronization in LogManager is something that has always proved
to require careful thinking ;-)
Is it OK with you if I log a follow up RFE instead?
best regards
-- daniel
Regards, Peter
https://bugs.openjdk.java.net/browse/JDK-7113878
http://cr.openjdk.java.net/~dfuchs/webrev_7113878/webrev.00
best regards,
-- daniel
