Hi Mark, > -----Original Message----- > From: Mark Thomas [mailto:ma...@apache.org] > Sent: Thursday, October 17, 2013 1:10 PM > To: Tomcat Developers List > Subject: Re: svn commit: r1533035 - > /tomcat/tc7.0.x/trunk/webapps/examples/WEB- > INF/classes/websocket/drawboard/Room.java > > On 17/10/2013 11:53, Mark Thomas wrote: > > On 17/10/2013 11:50, Konstantin Preißer wrote: > >> Hi Mark, > >> > >>> -----Original Message----- > >>> From: Mark Thomas [mailto:ma...@apache.org] > >>> Sent: Thursday, October 17, 2013 12:49 PM > >>> To: Tomcat Developers List > >>> Subject: Re: svn commit: r1533035 - > >>> /tomcat/tc7.0.x/trunk/webapps/examples/WEB- > >>> INF/classes/websocket/drawboard/Room.java > >>> > >>> On 17/10/2013 11:39, Konstantin Kolinko wrote: > >>>> 2013/10/17 <ma...@apache.org>: > >>>>> Author: markt > >>>>> Date: Thu Oct 17 10:32:21 2013 > >>>>> New Revision: 1533035 > >>>>> > >>>>> URL: http://svn.apache.org/r1533035 > >>>>> Log: > >>>>> Avoid hangs on shutdown > >>>>> > >>>>> Modified: > >>>>> tomcat/tc7.0.x/trunk/webapps/examples/WEB- > >>> INF/classes/websocket/drawboard/Room.java > >>>>> > >>>> > >>>> I expect this to > >>>> a) fail when running with a security manager > >>>> b) cause a memory leak when examples app is reloaded, as you will get > >>>> a new instance of ShutdownDetection class in webapp's classloader > and > >>>> new instance of shutdown hook. > >>> > >>> I'm open to better suggestions. Another option I considered was just > >>> removing the call to roomGraphics.dispose(); and letting GC take care of > >>> things. > >>> > >>> Alternatively, we could provide some form of global flag. > >>> > >>> I think I prefer the global flag that indicates that a shutdown is in > >>> process. I can think of several other places where such a flag would > >>> have been useful and we can expose it through a custom servlet context > >>> attribute such as > "org.apache.tomcat.JVM_SHUTDOWN_IN_PROGRESS". > >>> > >>> I'll start looking at the global flag option. Meanwhile, any suggestions > >>> on how to improve the fix or an alternative fix welcome. > >> > >> Can you give me some insight of why Grahpics2D.dispose() may cause a > hang on shutdown? I have never seen .dispose() causing a hang, at least not > on Windows. > >> If it hangs, might this be a result of different threads using the Grahpics > object? > > > > Clean 7.0.x build > > catalina.bat start > > CTRL-C in the Tomcat Window > > > > The result is an exception written to stderr (I assume err rather than > > out) and Tomcat fails to stop. The exception is triggered by AWT trying > > to register a shutdown hook after the shutdown process has started. > > Ah. More info. It only occurs with Java 6. > > We could just classify this as a JVM bug and more on. That said, I think > some changes to the init code could probably avoid this in Java 6 as > well. I'll take a quick look.
OK, thanks. However, I can reproduce the hang now with Tomcat 7 on Java 7. Although I do not get a exception, I get a short hang and a warning: "The executor associated with thread pool [http-bio-8080] has not fully shutdown. Some application threads may still be running." After that, Tomcat closed. I do not get this with Tomcat 8. My reaction also would have been to just remove the dispose() in the Tomcat 7 example since it is unlikely that the examples application is reloaded many times on a Tomcat run and creates too much Graphics2D objects that the GC does not dispose. But of course, I have nothing against a better solution if you find one. :) Regards, Konstantin Preißer --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org
