Re: [ROOT] 3.05.03 feature change?

From: Clark McGrew (clark.mcgrew@sunysb.edu)
Date: Mon Mar 31 2003 - 05:05:10 MEST


Hello Again,

I did some digging to isolate the problem I reported below.  The crash
I'm seeing is caused in the custom streamer introduced in
TBranchElement.cxx between version 1.104 and 1.105.  I will try to
generate some example code to tickle the bug, but the symptom is that
TBranchElement::Streamer() calls TStreamerInfo::ForceWriteInfo() by way
of fInfo.  TStreamerInfo::ForceWriteInfo() recurses infinitely until the
stack is full.  I haven't figured out why ForceWriteInfo is stuck in
infinite recursion.

I see the symptom with 3.05.03, and it first appears with in cvs
versions for 6 March 2003.  I'm working on debian linux with g++-3.2. 
I'm sorry this is a little vague at the moment, and will try to get some
example code soon.

Thanks,
Clark

On Sun, 2003-03-30 at 14:31, Clark McGrew wrote:
> Hi Rene,
> 
> Thanks so much for replying on a Sunday.  At first I thought it was a
> compile or LD_LIBRARY_PATH problem, and have check three ways backward
> and forward.  I keep several versions of root on my machine, so it is
> possible that I've goofed.  I'll delete all the objects one more time
> and triple check all the paths.   
> 
> Personally, I suspect that it's a deep, nasty bug in my code that is
> just now being tickled.  I just wanted to make sure the interface hadn't
> changed before I starting a major I/O debugging session.
> 
> Thanks,
> Clark
> 
> On Sun, 2003-03-30 at 11:17, Rene Brun wrote:
> > Hi Clark,
> > 
> > This type of trouble may appear when you have a mismatch
> > in your LD_LIBRARY_PATH or you did not recompile some of your classes.
> > Root version 3.05/03 is back compatible with previous versions.
> > 
> > Rene Brun
> > 
> > On 
> > 30 Mar 2003, 
> > Clark McGrew wrote:
> > 
> > > Hello,
> > > 
> > > I'm running into a problem reading and writing files using TFile that
> > > appeared when I upgraded from 3.05.02 and 3.05.03.  This isn't a "bug
> > > report", but I am checking to see if anybody else has seen a problem, or
> > > if there is a known interface change that I've missed before I start a
> > > major "what changed" debug.
> > > 
> > > The problem occurs when I am about to close a TFile with the approximate
> > > idiom:
> > > 
> > > 	aTFile.Write();
> > > 	aTFile.Close();
> > > 
> > > This works in 3.05.02, and core dumps in 3.05.03.  Also, I can't read 
> > > files written with 3.05.02 using 3.05.03 (files look fine with '02).   
> > > If there haven't been any expected changes in the tfile semantics, I'll
> > > chase down a short code snippet to isolate the problem.
> > > 
> > > Thanks in advance.
> > > 
> > > Clark
> > > 
-- 
Clark McGrew <clark.mcgrew@sunysb.edu>
University at Stony Brook, Dept. of Physics and Astronomy



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