yeah, it would not be straightforward, which is why it will take some thinking. might be one of these things where the default behavior is safe and coarse grained but then provide a way to turn on fancy multithreading and provide calls to notify the system of changes like the one you're talking about. there's a pretty long discussion in this topic for sure.
igor.vaynberg wrote: > > On 7/6/07, Jonathan Locke <[EMAIL PROTECTED]> wrote: >> >> >> >> yeah, even my pre-emptive lock claiming idea would require some thinking >> about versioning. what happens to all the versioning information >> recorded >> by the pre-empted thread? we'd need a transacted commit on that. >> >> actually, if you think about database technologies here, one way to get >> better >> locking behavior might be to refactor all the component mutation code in >> wicket >> so it's all optimistically locked, isolated and transacted. threads >> could >> freely do >> mutations, but those changes would be magically invisible to other >> threads. >> then at the end of the request, versioning would try to commit the >> changes >> made to the hierarchy. if the transaction failed due to optimistic >> locking >> (writer >> contention to the component hierarchy), the thread could actually discard >> its >> results and re-do the request on the new hierarchy before returning >> results. >> all of the usual problems with reader/writer multithreading come into >> play >> here >> of course... component mutating threads (writers) could potentially >> starve >> and >> so forth... but it's something worth thinking about anyway. > > > this sounds great for code we control, but what about user code? if the > user > calls a method from onclick that invocation needs to be threadsafe - it > might be mutating fields on that component. > -igor > > > Eelco Hillenius wrote: >> > >> >> in general the problem with wicket is that it has a stateful >> >> and >> >> mutable component model. if one thread is busy recursively rendering >> >> component >> >> A and another thread decides to remove it in the middle of that >> process, >> >> what then? >> >> to allow the two threads to both work on the component model, you can >> >> either >> >> block >> >> and serialize the threads (current approach) or you can copy the at >> least >> >> part of the >> >> model (and any naive approach here would be totally >> prohibitive). since >> >> a >> >> wicket >> >> ajax request to do a partial render is often localized to a particular >> >> piece >> >> of the model, >> >> it might be possible to do some tree-granularity lock splitting, but >> this >> >> is >> >> a really >> >> major piece of work and will require at least a lot of discussion and >> >> another release >> >> cycle after 1.3 to address. >> > >> > Even if we would be able to provide a thread safe programming model by >> > doing lots of magic under the hood, we would still have a problem >> > determining versions. But sure, we should try to keep pushing the >> > envelope where we can. >> > >> > Eelco >> > >> > >> ------------------------------------------------------------------------- >> > This SF.net email is sponsored by DB2 Express >> > Download DB2 Express C - the FREE version of DB2 express and take >> > control of your XML. No limits. Just data. Click to get it now. >> > http://sourceforge.net/powerbar/db2/ >> > _______________________________________________ >> > Wicket-user mailing list >> > Wicket-user@lists.sourceforge.net >> > https://lists.sourceforge.net/lists/listinfo/wicket-user >> > >> > >> >> -- >> View this message in context: >> http://www.nabble.com/Multiple-asynchronous-Ajax-calls---once-again-tf4034837.html#a11475099 >> Sent from the Wicket - User mailing list archive at Nabble.com. >> >> >> ------------------------------------------------------------------------- >> This SF.net email is sponsored by DB2 Express >> Download DB2 Express C - the FREE version of DB2 express and take >> control of your XML. No limits. Just data. Click to get it now. >> http://sourceforge.net/powerbar/db2/ >> _______________________________________________ >> Wicket-user mailing list >> Wicket-user@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/wicket-user >> > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > Wicket-user mailing list > Wicket-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wicket-user > > -- View this message in context: http://www.nabble.com/Multiple-asynchronous-Ajax-calls---once-again-tf4034837.html#a11475826 Sent from the Wicket - User mailing list archive at Nabble.com. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Wicket-user mailing list Wicket-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wicket-user
