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How to: Launch a stand-alone .NET Framework application with the profiler to collect memory data by using the command line

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Applies to: yesVisual Studio noVisual Studio for Mac

Note

This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here

This topic describes how to use Visual Studio Profiling Tools command-line tools to start a .NET Framework stand-alone (client) application and collect memory data.

A profiling session has three parts:

  • Starting the application by using the profiler.

  • Collecting profiling data.

  • Ending the profiling session.

Note

To get the path to the profiling tools, see Specify the path to command line tools. On 64-bit computers, both 64-bit and 32-bit versions of the tools are available. To use the profiler command-line tools, you must add the tools path to the PATH environment variable of the Command Prompt window or add it to the command itself.

Start the application with the profiler

To start a target application by using the profiler, you use the VSPerfCmd.exe/start and /launch options to initialize the profiler and start the application. You can specify /start and /launch and their respective options on one command line.

You can also add the /globaloff options to pause data collection at the start of the target application. You then use /globalon to start to collect data.

To start an application by using the profiler

  1. Open a Command Prompt window.

  2. Start the profiler. Type:

    VSPerfCmd /start:sample /output: OutputFile [Options]

    • The /start:sample option initializes the profiler.

    • The /output:OutputFile option is required with /start. OutputFile specifies the name and location of the profiling data (.vsp) file.

      You can use any of the following options with the /start:sample option.

    Option Description
    /wincounter : WinCounterPath Specifies a Windows performance counter to be collected during profiling.
    /automark : Interval Use with /wincounter only. Specifies the number of milliseconds between Windows performance counter collection events. Default is 500 ms.

  3. Start the target application. Type:

    VSPerfCmd /launch : appName /gc:{allocation|lifetime}[Options]

    • The /gc:Keyword option is required to collect .NET Framework memory data. The keyword parameter specifies whether to collect memory allocation data, or to collect both memory allocation and object lifetime data.

      Keyword Description
      allocation Collect memory allocation data only.
      lifetime Collect both memory allocation and object lifetime data.

      You can use any of the following options with the /launch option.

    Option Description
    /args : Arguments Specifies a string that contains the command-line arguments to be passed to the target application.
    /console Starts the target command-line application in a separate window.
    /events : Config Specifies an Event Tracing for Windows (ETW) event to be collected during profiling. ETW events are collected in a separate (.etl) file.
    /targetclr : Version Specifies the version of the common language runtime (CLR) to profile when more than one version of the runtime is loaded in an application.

Control data collection

When the target application is running, you can control data collection by starting and stopping the writing of data to the file by using VSPerfCmd.exe options. Controlling data collection enables you to collect data for a specific part of program execution, such as starting or shutting down the application.

To start and stop data collection

  • The following pairs of options start and stop data collection. Specify each option on a separate command line. You can turn data collection on and off multiple times.

    Option Description
    /globalon /globaloff Starts (/globalon) or stops (/globaloff) data collection for all processes.
    /processon : PID processoff : PID Starts (/processon) or stops (/processoff) data collection for the process that is specified by the process ID (PID).
    /attach : PID /detach /attach starts to collect data for the process that is specified by PID (the process ID). /detach stops data collection for all processes.

  • You can also use the VSPerfCmd.exe/mark option to insert a profiling mark into the data file. The /mark command adds an identifier, a time stamp, and an optional user-defined text string. Marks can be used to filter the data.

End the profiling session

To end a profiling session, the profiler must be detached from all profiled processes and the profiler must be explicitly shut down. You can detach the profiler from an application that was profiled by using the sampling method by closing the application or by calling the VSPerfCmd /detach option. You then call the VSPerfCmd /shutdown option to turn off the profiler and close the profiling data file. The VSPerfClrEnv /off command clears the profiling environment variables.

To end a profiling session

  1. Perform one of the following steps to detach the profiler from the target application:

    • Close the target application.

      -or-

    • Type VSPerfCmd /detach

  2. Shut down the profiler. Type:

    VSPerfCmd /shutdown

See also