From: "Brian W. Young" <[EMAIL PROTECTED]> > I saw the original post here, > > But can someone in basic terms explain where there may be a threading > issue? We use dom4j as part of a fully threaded server and I'd like to > know if there is anything I need to look out for. > > In many cases I use a shared dom4j document that many threads can read, > but modification of course is done through proper synchronization in my > own code. Is this enough? I think I'm hearing that it isn't.
One minor point. For optmisation, dom4j uses lazy evaluation; it tries for example not to create List implementations until it absolutely has to. So if you want to create a Document that is shared, in a read only state, across many threads, I'd recommend using the NonLazyDocumentFactory (in the org.dom4j.util package) to construct your documents. Its slower but should avoid any issues caused by multi-threaded access to the same document instance. SAXReader reader = new SAXReader(); reader.setDocumentFactory(new NonLazyDocumentFactory()); Document safeDoc = reader.read( "foo.xml" ); James ------- http://radio.weblogs.com/0112098/ > > Thanks! > > Brain, Jim wrote: > > >I also echo a need to resolve this. We are currently having this issue in > >production on a mission critical (probably everyone says that, but it is an > >app entry system for an insurance carrier, so I hope that qualifies) > >application running on IBM OS/390 (ye old mainframe). Before I pull the > >HashTable version, I'd like to hear what the longer term plans are, since > >there is a considerable ramp time on getting new cuts of code through our > >integration management process. > > > >Jim > > > > > >Jim Brain, [EMAIL PROTECTED] > >"Researching tomorrow's decisions today." > >(319) 369-2070 (work) > >SYSTEMS ARCHITECT, ITS, AEGON FINANCIAL PARTNERS > > > > -----Original Message----- > >From: David D. Lucas [mailto:ddlucas@;lse.com] > >Sent: Tuesday, October 22, 2002 9:34 AM > >To: [EMAIL PROTECTED]; [EMAIL PROTECTED] > >Cc: Brain, Jim > >Subject: Thread Safety > > > >Sorry for the cross post, but I have not seen any feedback on the thread > >safety issues. I have taken the stock CVS and changed all the HashMaps > >to Hashtables to get things to work in our server environment. > > > >I would like to know what the long term direction is for thread safety > >and if anyone would like my changes? > > > >Basically I took all the classes in org.dom4j.* and org.dom4j.tree.* and > >changed them to use Hashtable. The methods out there with > >synchronization are probably no longer needed now that we have a > >Hashtable. I am looking at an alternative approach to keep the HashMap > >and performance without having thread related failures. > > > >All this came from the QNameCache getting corrupted when two threads hit > > it at the same time. It appears that one did a put while another did > >a get and resulted in a null coming back. > > > >Please let me know what I should do next with the code. If you want I > >can post it or check it in (given access to development CVS). > > > >Thanks in advance, > >Dave > > > > > > > > > > > ------------------------------------------------------- > This sf.net emial is sponsored by: Influence the future > of Java(TM) technology. Join the Java Community > Process(SM) (JCP(SM)) program now. > http://ad.doubleclick.net/clk;4699841;7576301;v?http://www.sun.com/javavote > _______________________________________________ > dom4j-user mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/dom4j-user > __________________________________________________ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com ------------------------------------------------------- This sf.net emial is sponsored by: Influence the future of Java(TM) technology. Join the Java Community Process(SM) (JCP(SM)) program now. http://ads.sourceforge.net/cgi-bin/redirect.pl?sunm0002en _______________________________________________ dom4j-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dom4j-user
