RE: Multithreaded TImage

From: Valeri Onuchin <Valeri.Onoutchine_at_cern.ch>
Date: Wed, 11 Apr 2012 04:51:34 +0000

Hi Jakub,
TImage implementation was not intended to be thread-safe at the time it was created. If it's possible could you send me reproducible example to investigate. Which platform do you use, version, script or compiled code? Which methods of TImage you need to be threadsafe.

Regards. Valeriy  

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From: owner-roottalk_at_root.cern.ch [owner-roottalk_at_root.cern.ch] on behalf of Jakub Čermák [jakub_at_jcermak.cz] Sent: 10 April 2012 00:50
To: roottalk_at_root.cern.ch
Subject: [ROOT] Multithreaded TImage

Hello,
I've following problém with TImage class. I use TImage::Open to load images. Everything was ok until I decided to use more threads, after that is started to fail with "Error in <TBufferFile::WriteObjectAny>: ptrClass argument may not be 0". I don't use any other ROOT functions and each thread works with its own data, there is no data sharing. My code:
TImage *img = TImage::Open(m_FilePaths[m_DataFileID].c_str()); unsigned int *data = img->GetArgbArray(); // ... some read operations on the data

So, is the TImage::Open thread-safe? I can't see why it shouldn't be, but I want to be sure. If it's really thread-safe, what can be the problem here?

Thanks in advance

Best regards

Jakub Čermák Received on Wed Apr 11 2012 - 06:51:41 CEST