[vbox-dev] Visual Studio multithreaded debugging broken in VirtualBox

Petr Vones petr.v at mujmail.cz
Tue May 7 11:26:24 PDT 2013


thanks for reply. The issue is reported for various Intel CPUs only yet, 
unfortunately there are probably few developers using AMD based machines.

There is valuable feedback to the issue https://www.virtualbox.org/ticket/9659 
especially latest reports. To summarize it:

- it affects Visual Studio 2008, 2010, 2012 breakpoints in .NET code made via 
Visual Studio code editor
- it does not affect breakpoints in native C++ code (at least has not been 
confirmed yet)
- it does not depend on host OS, it is reported for Windows, Linux and Mac hosts
- it affects both x86 and x64 Windows guests
- it affects both x86 and x64 debugged process in x64 guest but the error 
behavior is usually different
- the issue seems to be more visible and frequent with latest VirtualBox 
versions 4.2.x

- disabling Nested Paging does not help
- setting single CPU only in virtual machine and VirtualBox.exe (host) process 
CPU affinity to single CPU (via Task Manager -> Set Affinity) have noticeable 
effect on the number of occurrences but the issue is still there anyway.

The most simple C# code example to always reproduce it is:

Hope this helps.


Ramshankar wrote, On 2.5.2013 23:22:
> Firstly, thank you for the report.
> I will try test this later this week or next week, I'm hoping setting up a test
> VM won't take long...
> We're aware of issues involving hardware debug breakpoints and exceptions
> (especially on Intel). Unfortunately, I cannot give you an estimate of the fix.
> Just one question: Is this restricted to Intel CPUs or does it happen on AMD
> CPUs as well?
>  From quickly skimming through the public report and a VBox.log uploaded 19
> months ago, I gather it's only Intel but a confirmation would be nice.
> Regards,
> Ram.

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