Fwd: RE: [ROOT] bug in TCanvas TestBit ??

From: joe robe (joer00@yahoo.com)
Date: Sat Oct 06 2001 - 18:23:12 MEST 

hello rene,

I am using VC++ on w2k server on dual xeon with 500mb
ram and the latest root binaries.

attached you find a message from axel neuman
describing the same problem, so it seems you are aware
of it.

My current code might be to much stuff to send it, I
will try to reproduce the behavior with less code.

Undoubtly it ALWAYS crashes in debug mode ! In release
mode I could avoid teh crahs now by IMMEDIATELY in the
FIRTS LINE create the canvas. This might indeed work
because in that 10 of a second I do not move the mouse
over the screen.

Joe


Note: forwarded message attached.


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attached mail follows:

Hi Joe, assuming that you use any windows version of root: Try doing the same and moving your mouse pointer away from the desktop area in which the canvas is created and then execute your windows program. Does the problem vanish? If that's the case, PLEASE send me an answer. I'm trying to convince the root guys since about 6 months to implement a fix to a bug in the TCanvas creation, which has consequences only on Windows. The TCanvas initialization happens AFTER the message handler thread is created, in which case the message handler can access an uninitialized TCanvas (that's why it only happens when your mouse pointer is over the freshly created canvas). You can check that the TCanvas is not initialized by looking at its members: In debug mode they're set to 0xbaadf00d (yes, that's funny). Cheers, Axel. > -----Original Message----- > From: owner-roottalk@pcroot.cern.ch > [mailto:owner-roottalk@pcroot.cern.ch]On Behalf Of joe robe > Sent: Friday, October 05, 2001 1:55 PM > To: roottalk@pcroot.cern.ch > Subject: [ROOT] bug in TCanvas TestBit ?? > > > rooters, > > i go mad with some problems i get SOMETIMES drawing > canvas. > There is a crash occuring in some of my programs > where I cant tell why and WHEN they occur, but > CONSITENTLY on some graphic output it crashes and > debug points always to the same TEstBit method. > > I was reading somwehere regarding a bug in cancvas > intitilaisation, is there a work around ? In most > times the stuff works if one does NOT create the > canvas and let it create by default calling TH2D etc. > > joe > > > __________________________________________________ > Do You Yahoo!? > NEW from Yahoo! GeoCities - quick and easy web site hosting, just > $8.95/month. > http://geocities.yahoo.com/ps/info1 >

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