Sample

This tutorial will show how to instrument a unit test DLL for performance profiling. Visual Studio will allow you to do performance profiling on individual tests (i.e. functions) in a test suite. This can be done in the user interface (i.e. UI or IDE). However if you have a unit test DLL that contains lots of unit tests or test methods, it’s apparently not possible to do performance profiling in the IDE.

Here was my original question:

 Question on MSDN forums

I have a MS Unit Test DLL written in C# that targets a C++/CLI managed assembly. I have roughly 60 unit tests in that unit test dll. What I would like to do is run all the unit tests under the performance profiler, in the IDE. That is using the performance explorer to run a performance session for all the unit tests in my test DLL. I know how to do this from the command line, but I feel that is a last resort. I’d like to do this in the IDE if possible. It is possible to create a performance session for one unit test in the unit test DLL. The steps are listed here: ms-help://MS.VSCC.v90/MS.MSDNQTR.v90.en/dv_vsetlt01/html/4cc514d2-47bd-4f1c-a039-5ffae7c68bf1.htm i.e. Right click over a test result, and select "Create Performance Session". Whereupon the Performance Explorer will show a new session based off of one unit test. That’s great, but I’ve got 60 unit tests in my DLL. I don’t want to have to create 60 performance sessions.

Preparation

Build the code that you will be testing. In my case it was the following DLL’s (Assuming a common root folder)

Then just to play it safe, run all the unit tests (This can be done in the IDE) in UnitTest.dll. It pays to be paranoid like this since if you want to detect bugs early and swiftly.

Now the strategy for profiling an entire DLL is to:

• Instrument the DLL. This means to inject performance related commands into the code. Don’t worry it’s perfectly safe.
  • Turn on performance profiling via a global command.
    • Run your unit tests. Here is where the real work gets done.
  • Turn off performance profiling via a global command. (A results file gets saved somewhere).
• Un-Instrument the DLL. This means restoring it to it’s original state. (i.e. Don’t ship a DLL with performance profiling enabled).

Instrument the Binaries

I instrument my DLL’s using the following batch script called: Instrument_ON.bat    

The results of instrumenting it looks like this:

Instrumenting Binary      Microsoft (R) VSInstr Post-Link Instrumentation 9.0.30729 x86       Copyright (C) Microsoft Corp. All rights reserved.

File to Process:         F:\CodePlex\UnderstandAPI\Managed\ManagedAPI\Win32\Debug\UnderstandWrapper.ManagedAPI.dll –> F:\CodePlex\UnderstandAPI\Managed\ManagedAPI\Win32\De       bug\UnderstandWrapper.ManagedAPI.dll       Original file backed up to F:\CodePlex\UnderstandAPI\Managed\ManagedAPI\Win32\Debug\UnderstandWrapper.ManagedAPI.dll.orig

Successfully instrumented file F:\CodePlex\UnderstandAPI\Managed\ManagedAPI\Win32\Debug\UnderstandWrapper.ManagedAPI.dll.      Warning VSP2013 : Instrumenting this image requires it to run as a 32-bit process.  The CLR header flags have been updated to reflect this.       Microsoft (R) VSInstr Post-Link Instrumentation 9.0.30729 x86       Copyright (C) Microsoft Corp. All rights reserved.

File to Process:         F:\CodePlex\UnderstandAPI\Managed\UnitTest\bin\x86\Debug\UnitTest.dll –> F:\CodePlex\UnderstandAPI\Managed\UnitTest\bin\x86\Debug\UnitTest.dll       Original file backed up to F:\CodePlex\UnderstandAPI\Managed\UnitTest\bin\x86\Debug\UnitTest.dll.orig

Successfully instrumented file F:\CodePlex\UnderstandAPI\Managed\UnitTest\bin\x86\Debug\UnitTest.dll.      Press any key to continue . . .

Turn on Monitor

I then turn on performance profiling using the following batch script called: Performance_ON.bat       

The results of this batch scripts looks like this:

Turning ON performance coverage session recorder      Microsoft (R) VSPerf Command Version 9.0.30729 x86       Copyright (C) Microsoft Corp. All rights reserved.

Press any key to continue . . .

The results of this script is it starts another process that will monitor any application that happens to be instrumented with performance profiling, or code coverage profiling. In our case it started a process called VsPerfMon.exe:

Run Unit Tests

I then run all the unit tests in my DLL using another batch script. Now I have two build configurations (debug and release) so I have two batch scripts to run those: Run_Tests_Debug.bat and Run_Tests_Release.bat. Here is one of them:    

Notice there the actual call to mstest.exe is what runs the unit tests. Notice that I piped the results of running the actual unit tests into a text file (i.e. results.txt). I did this because it gives me a more permanent record of how my unit tests did.

The mstest.exe file resides on my computer at:

"C:\Program Files (x86)\Microsoft Visual Studio 9.0\Common7\IDE\MSTest.exe"

The output, to the console window, of this script on my looks like the following:

Running Unit Tests      Enabling VSPerf Trace Profiling of managed applications (excluding allocation profiling).

Current Profiling Environment variables are:      COR_ENABLE_PROFILING=1       COR_PROFILER={6468ec6c-94bd-40d3-bd93-4414565dafbf}       COR_LINE_PROFILING=0       COR_GC_PROFILING=0       Setting environment for using Microsoft Visual Studio 2008 x86 tools.       Press any key to continue . . .

Noticed I redirected the standard output (standard out) to a text file. The results.txt file looks like this:

Microsoft (R) Test Execution Command Line Tool Version 9.0.30729.1      Copyright (c) Microsoft Corporation. All rights reserved.       Loading F:\CodePlex\UnderstandAPI\Managed\UnitTest\bin\x86\Debug\UnitTest.dll…       Starting execution…

Results               Top Level Tests      ——-               —————       Passed                UnitTest.DatabaseTest.DatabaseTest_GetAllEntities       Passed                UnitTest.DatabaseTest.DatabaseTest_GetFileEntities       Passed                UnitTest.DatabaseTest.DatabaseTest_LookupEntity       Passed                UnitTest.DatabaseTest.DatabaseTest_LookupEntitybyReference       Passed                UnitTest.DatabaseTest.DatabaseTest_LookupEntityUnique       Passed                UnitTest.DatabaseTest.DatabaseTest_LookupFile       Passed                UnitTest.DatabaseTest.DatabaseTest_Misc       Passed                UnitTest.DatabaseTest.DatabaseTest_OpenClose       Passed                UnitTest.Derived.ClassTypeTest.TestClassNests       Passed                UnitTest.Derived.ClassTypeTest.TestClassType       Passed                UnitTest.Derived.ClassTypeTest.TestClassTypeDerivedFrom       Passed                UnitTest.Derived.ClassTypeTest.TestClassTypeEnums       Passed                UnitTest.Derived.ClassTypeTest.TestClassTypeFields       Passed                UnitTest.Derived.ClassTypeTest.TestClassTypeInheritance       Passed                UnitTest.Derived.ClassTypeTest.TestClassTypeTemplates       Passed                UnitTest.Derived.ClassTypeTest.TestClassTypeUnions       Passed                UnitTest.Derived.ClassTypeTest.TestGetDefinedMethods       Passed                UnitTest.Derived.ClassTypeTest.TestGetMethods       Passed                UnitTest.Derived.EnumTypeTest.EnumTest_Enumerators       Passed                UnitTest.Derived.EnumTypeTest.EnumTest_Type       Passed                UnitTest.Derived.FileEntityTest.TestFileEntity       Passed                UnitTest.Derived.FileEntityTest.TestFileEntity_base_h       Passed                UnitTest.Derived.FileEntityTest.TestFileEntity_classes_h       Passed                UnitTest.Derived.FileEntityTest.TestFileEntityClassTypes       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Constructor       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Inline       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Inline_B       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_LexerStuff       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Member_A       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Member_B       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Member_C       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Member_D       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Member_E       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Member_F       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_MemberBlank       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Overrides       Passed                UnitTest.Derived.MethodTypeTest.MethodTest_Pure       Passed                UnitTest.EntityTest.EntityTest_Basic       Passed                UnitTest.EntityTest.EntityTest_Comments       Passed                UnitTest.EntityTest.EntityTest_Comments_Enums       Passed                UnitTest.EntityTest.EntityTest_Comments_FunctionDeclarations       Passed                UnitTest.EntityTest.EntityTest_Comments_FunctionDefinitions       Passed                UnitTest.EntityTest.EntityTest_Comments_Typedefs       Passed                UnitTest.EntityTest.EntityTest_FileReference       Passed                UnitTest.EntityTest.EntityTest_LineNumbers       Passed                UnitTest.EntityTest.EntityTest_LineNumbers_FunctionDeclarations       Passed                UnitTest.EntityTest.EntityTest_LineNumbers_FunctionDefinitions       Passed                UnitTest.EntityTest.EntityTest_LineNumbers_UnresolvedMethods       Passed                UnitTest.EntityTest.EntityTest_Refs       Passed                UnitTest.EntityTest.EntityTest_Types       Passed                UnitTest.KindTest.KindTest_Basic       Passed                UnitTest.LexerTest.Lexer_Test       Passed                UnitTest.LexerTest.Lexer_Test_GetLexeme       Passed                UnitTest.LexerTest.Lexer_Test_Next       Passed                UnitTest.LexerTest.Lexer_Test_Previous       Passed                UnitTest.LexerTest.Lexer_Test_Ref       Passed                UnitTest.ReferenceTest.ReferencesTest_Basic       Passed                UnitTest.ReferenceTest.ReferencesTest_Copying       58/58 test(s) Passed

Summary      ——-       Test Run Completed.         Passed  58         ———-         Total   58       Results file:      F:\CodePlex\UnderstandAPI\Managed\TestResults\Chris Johnson_CHRISJOHNSON-PC 2010-02-17 23_38_54.trx       Run Configuration: Default Run Configuration

Feels good to see all the unit tests pass. But now I have to save out the results of the performance profiling. And to do this, I now have to turn off the VsPerfMon.exe process that is running, and was running when I ran my unit tests.

Turn off Monitor

I have a batch script that turns off monitoring and saves out a results file containing all the profiling goodness. Performance_OFF.bat

The results of this batch script looks like this:

Turning off performance coverage session recorder      Microsoft (R) VSPerf Command Version 9.0.30729 x86       Copyright (C) Microsoft Corp. All rights reserved.

Shutting down the Profile Monitor      ————————————————————       Press any key to continue . . .

Now a new file is saved out to my computer:

F:\CodePlex\UnderstandAPI\Managed\Performance\ManagedAPI.vsp

Notice the name: ManagedAPI.vsp. This is the same name I passed in when I turned on the Performance Monitor. Remember this?

from: Performance_ON.bat

…

VsPerfCmd /start:trace /output:ManagedAPI.vsp

Now at this point, you can do two things:

1. Examine your performance results. This is done by double clicking the ManagedAPI.vsp file. This will just launch visual studio, and display the results of your tests:
2. Or Uninstrument your DLL’s. It’s never a good idea to ship DLL’s with instrumentation in them.  

Un-Instrument the Binaries

I have a script that does this for me: Instrument_OFF.bat

When I run this, I get the following results in the command window:

Removing Instrumented Files      Press any key to continue . . .

However, sometimes I do this only after I reviewed my performance results. Since the performance results display in visual studio may be dependent on the instrumented binaries to properly display its data.

View Results

Now that you have your .vsp file it is time to open it. The file ManagedAPI.vsp shows the following in visual studio:

From there you can analyze the results and find your performance bottlenecks.