Re: X11 and Threads...

From: Fons Rademakers <>
Date: Thu, 21 Dec 2006 17:48:13 +0100

Hi Daniel,

   updating canvases from different threads is not supported. What should be done is to concentrate all canvas drawing in one thread while the object being drawn can be modified in different threads (like histogram or graph updating). See for example the tutorial: tutorials/thread/threadsh1.C.

Cheers, Fons.

daniel cussol wrote:
> Hello everybody,
> I am trying to build a multi-thread application in which I need to
> refresh canvases. Unfortunately, this leads usually to a complete
> freezing of my application. It seems as it is mentioned in the
> documentation that there still are some problems with W11 and threads. I
> have nevertheless noticed that when I select the "interrupt" item in the
> "Option" menu of the TCanvas before refreshing it, all seemed to be Ok.
> My question is then: what sequence of commans and/or code is activated
> when one select the "interrupt" item in the "Option" menu of the
> TCanvas? I was not clever enough to obtain this information from the
> source code.
> I run ROOT v5.12.00 on MacOs X.3.9 and on SL4.
> Thanks for your help.

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Received on Thu Dec 21 2006 - 17:47:32 MET

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