On Tue, 2010-07-13 at 13:32 -0700, Harold Lee wrote: > Regarding this JDK bug: > http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6403933 > > I think we are experiencing this using HttpCore on Linux with Java > 1.6. We wind up leaking socket descriptors until the JVM process runs > out. We also wind up having to start a new reactor thread, which > creates a new Selector. The old reactor thread keeps running and the > thread dump shows it in sun.nio.ch.EPollArrayWrapper.epollWait as > reported by others in the bug report above. >
Folks Anyone experienced anything like that? The looks pretty old, but there has been no reports of similar problems with HttpCore NIO. I am using Linux / JDK 1.6 on a daily basis when hacking on HttpCore but I have not encountered such a problem yet. > Here's the change that the Glassfish team made to work around this JDK bug: > > http://fisheye5.cenqua.com/browse/glassfish/appserv-http-engine/src/java/com/sun/enterprise/web/connector/grizzly/ByteBufferInputStream.java?r1=1.8&r2=1.9 > > From my reading, the Glassfish code is much simpler than the HttpCore > NIO code: they're registering interest for just 1 socket and using > Selector.select() to wait for data from that socket. For HttpCore NIO, > it isn't yet clear to me how we can detect which selector is "trashed" > in order to cancel it and recreate it. > > I'm working on a workaround in AbstractMultiworkerIOReactor.java. If > selector.select returns 0 (setting readyCount to 0) then we don't know > whether this bug hit us or we just had a timeout. The problem is that it is perfectly valid for a selector to return 0 ready count. This condition alone is not sufficient to assume the selector is trashed. > To be safe, I think > we need to close every registered SelectorKey and then call > selector.selectNow() to flush them. Then we can create a new > SelectorKey for each and reregister them. The only way to make it less > common, I think, is to use a long selectTimeout value so that the odds > of a timeout are low. Ugly, but I hope it will work. > This will unfortunately screw up handling of new / closed channels as well timeout logic. The work-around looks butt ugly and would require tons of fairly complex code. Is there a way to reproduce the issue with a test scenario, so we could look for alternative approaches? Cheers Oleg --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
