Hello Robbert, The SVN version is missing the changes (ReadQueue definition) to the Databasepager header file.
-- Roland > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf > Of Robert Osfield > Sent: zondag 15 juni 2008 18:03 > To: OpenSceneGraph Users > Subject: Re: [osg-users] New Improved DatabasePager,now with > even more threading! Please take a taste today :-) > > Hi Guys, > > While away on training last week, we came across the Windows > debug build reporting problem in std::sort and find calls, > and investigations into the issue suggested that it was down > to the cull thread modifying the DatabaseRequest fields at > the same time that those same fields were being used inside > the std algorithms being run by the DatabasePager threads. > The worst thing that would actually happen is that very > occassionally the list would be sorted into incorrect order, > but this in itself would only lead to a slightly sub-optimial > ordering of loading tiles, it shouldn't actually break any > app - so it's really more of an issue with the debugger being > overly strict rather than having a serious race condition > that would cause real problems. > > However, even having a benign, occasional, slightly > sub-optimal ordering is a problem if end users under Windows > are going to keep stumbling over this issue to due to > compiler debugging screaming that there is a serious problem > and crashing - so it's a community support problem rather > than actual a real problem for proper applications, but > having more support than we already have is an issue so I've > gone ahead and found a solution. Now checked into SVN is an > addition of a mutex lock on the current queue that a > DatabaseRequest is a member inside the code that updates the > DatabaseRequest parameters. This fix should prevent the > problems appearing under VisualStudio debug build, it alas > will also mean that all users will have to pay the cost of > an non essential mutex lock. > > Could you guys do an svn update and let me know how things go. > > Robert. > > > On Fri, Jun 13, 2008 at 10:48 AM, Serge Lages > <[EMAIL PROTECTED]> wrote: > > Hi James, > > > > I tried to look to this problem but can't find anything, > moreover it > > seems to work without problems in release (I'll try to make some > > stress tests soon to be sure). > > > > On Fri, Jun 13, 2008 at 1:02 AM, Lynch, James > <[EMAIL PROTECTED]> > > wrote: > >> > >> I'm having a similar issue with > >> DatabasePager::RequestQueue::takeFirst() > >> > >> (osg trunk, Debug build, windows XP VS2005). I'm getting some > >> assertion errors at _requestList.sort ("sequence not > ordered"). Even > >> after adding the updateBlock(). > >> > >> > >> I'm pretty new to this code section, so I'm probably off > base here: > >> Is it possible that the state of the databaseRequest > objects within > >> the list are being updated (from other threads) during the sort? > >> > >> IE. If the _timestampLastRequest or _priorityLastRequest > are changing > >> during the sort, the sort could become unstable. > >> > >> > >> _______________________________________________ > >> Jim Lynch > >> > >> -----Original Message----- > >> On Tue, May 27, 2008 at 12:08 PM, Tim Moore <timoore at redhat.com> > >> wrote: > >> > > >> > Indeed. I've made the necessary changes to FlightGear, > and it seems > >> > to be working fine. > >> > >> Except for being a cpu hog. > >> > >> Apparently, the pager thread is not blocked properly and > continuously > >> spins. The fact that the queue is empty is confirmed by the debug > >> messages printed after the block call: > >> HANDLE_NON_HTTP 0: _pager->_requestList.size()= 0 to delete = 0 > >> > >> I have been trying to find the place where the blocking is > >> re-established when the queue goes empty, but could not > find it. So I > >> added an updateBlock() call at the end of > >> DatabasePager::RequestQueue::takeFirst that seems to fix the issue. > >> Could have added the call within the if-block, but this has the > >> additional benefit of stopping runaway loops should > somehow the pager > >> thread get woken up without work to do. > >> > >> Index: DatabasePager.cpp > >> =================================================================== > >> --- DatabasePager.cpp (revision 8398) > >> +++ DatabasePager.cpp (working copy) > >> @@ -273,6 +273,7 @@ > >> databaseRequest = _requestList.front(); > >> _requestList.erase(_requestList.begin()); > >> } > >> + updateBlock(); > >> } > >> > >> > >> I am not sure if I need an osg-submissions mail for this? > >> > >> -- > >> Cheers, > >> Csaba/Jester.org/listinfo.cgi/osg-users-openscenegraph.org > >> > >> > >> The information contained in this communication may be > CONFIDENTIAL > >> and is intended only for the use of the recipient(s) named > above. If > >> you are not the intended recipient, you are hereby > notified that any > >> dissemination, distribution, or copying of this > communication, or any > >> of its contents, is strictly prohibited. If you have > received this > >> communication in error, please notify the sender and > delete/destroy > >> the original message and any copy of it from your computer > or paper files. > >> _______________________________________________ > >> osg-users mailing list > >> [email protected] > >> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph > >> .org > > > > > > > > -- > > Serge Lages > > http://www.tharsis-software.com > > _______________________________________________ > > osg-users mailing list > > [email protected] > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph. > > org > > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-opensce negraph.org > This e-mail and its contents are subject to the DISCLAIMER at http://www.tno.nl/disclaimer/email.html _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
