JustMock Lite is now open source

A few weeks ago something important happened. I am very happy to say that JustMock Lite is now open source. You can find it on GitHub.

In this post I would like to share some bits of history. JustMock was my first project at Telerik. It was created by a team of two. The managed API was designed and implemented by my friend and colleague Mehfuz and I implemented the unmanaged CLR profiler. The project was done in a very short time. I spent 6 weeks to implement all the functionality for so called elevated mocking. This includes mocking static, non-virtual methods and sealed types. After a few iterations JustMock was released early in April 2010.

I remember my very first day at Telerik. I had a meeting with Hristo Kosev and together we set the project goals. It turned out JustMock was just an appetizer for JustTrace. Back then we did not have much experience with the CLR unmanaged profiling API and Hristo wanted to extend Telerik product family with a performance and memory profiling tool. So, the plans were to start with JustMock and gain know-how before we build JustTrace. Step by step, we extended the team and JustMock/JustTrace team was created. Here is the door sign that the team used to have.


Later the team changed its name to MATTeam (mocking and tracing team).

Looking back, I think we built two really good products. As far as I know, at the time of writing this post JustMock is still the only tool that can mock of the most types from mscorlib.dll assembly. JustTrace also has its merits. It was the first .NET profiler with support for profiling managed Windows Store apps. I left MATTeam an year ago and I hope soon I can tell you about what I work on. Stay tuned.

Native code profiling with JustTrace

The latest JustTrace version (Q1 2014) has some neat features. It is now possible to profile unmanaged applications with JustTrace. In this post I am going to show you how easy it is to profile native applications with JustTrace.

For the sake of simplicity I am going to profile notepad.exe editor as it is available on every Windows machine. First, we need to setup the symbol path folder so that JustTrace can decode correctly the native call stacks. This folder is the place where all required *.pdb files should be.


In most scenarios, we want to profile the code we wrote from within Visual Studio. If your build generates *.pdb files then it is not required to setup the symbols folder. However, in order to analyze the call stacks collected from notepad.exe we must download the debug symbols from Microsoft Symbol Server. The easiest way to obtain the debug symbol files is to use symchk.exe which comes with Microsoft Debugging Tools for Windows. Here is how we can download notepad.pdb file.

symchk.exe c:\Windows\System32\notepad.exe /s SRV*c:\symbols*http://msdl.microsoft.com/download/symbols

[Note that in order to decode full call stacks you may need to download *.pdb files for other dynamic libraries such as user32.dll and kernelbase.dll for example. With symchk.exe you can download debug symbol files for more than one module at once. For more details you can check Using SymChk page.]

Now we are ready to profile notepad.exe editor. Navigate to New Profiling Session->Native Executable menu, enter the path to notepad.exe and click Run button. Once notepad.exe is started, open some large file and use the timeline UI control to select the time interval of interest.


In closing, I would say that JustTrace has become a versatile profiling tool which is not constrained to the .NET world anymore. There are plenty of unmanaged applications written in C or C++ and JustTrace can help to improve their performance. You should give it a try.

JustTrace Q1 2013 SP1 is out

The last two weeks I was busy with the latest release of JustTrace. We had some hard times with JustTrace Q1 2013 release but after all we managed to fix a critical bug and we shipped SP1 after one week. There are a lot of new features in this release but I am going to focus on one thing only:

Visual Studio integration is out-of-process

If you use Visual Studio 2012 then you probably noticed a new process XDesProc.exe on your machine.outofproc1

This is the new XAML UI Designer. Lets use Spy++ tool on the XAML designer in Visual Studio 2012 and see what’s interesting.outofproc3

If you convert 0x1554 to decimal number you will get 5460 and that’s the XDesProc.exe process id shown on the screen shot above. So, what we see in Visual Studio is actually a window that belongs to XDesProc.exe process. Moving the XAML UI Designer out of Visual Studio has a lot of benefits – better isolation, improved performance and higher resource utilization. The same approach is used by Internet Explorer, Firefox and Chrome. You can read the full story about XDesProc.exe here.

So, why is it important to use out-of-process integration with Visual Studio? The short answer is more memory space. At present Visual Studio is 32bit process and this means that it can use at most 4GB (in most cases 2GB). This is a serious limitation for most profiling tools including JustTrace. For a long time, we wanted to move JustTrace out of Visual Studio and finally we did it. At the same time, JustTrace was built around the idea to provide seamless integration with Visual Studio. I am happy to say that the new JustTrace gives you the best of both worlds. Try it and give us your feedback.