How to: Attach the profiler to a native stand-alone application and collect concurrency data by using the command line

Applies to: Visual Studio Visual Studio for Mac

This article describes how to use Visual Studio Profiling Tools command-line tools to attach the profiler to a running native (C/C++) stand-alone application and collect thread contention data.

While the profiler is attached to the application, you can pause and resume data collection. To end a profiling session, the Profiler must no longer be attached to the application, and the Profiler must be explicitly shut down.

Attach the profiler to a running native application

To attach the profiler to a running native application

1. At a command prompt, type the following command:

   VSPerfCmd /start:concurrency

   You can use any of the options in the following table with the /start:concurrency option.

   Option	Description
   /user :[Domain\]Username	Specifies the optional domain and user name of the account to be granted access to the profiler.
   /crosssession	Enables profiling of processes in other logon sessions.
   /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. The default value is 500.
   /events : Config	Specifies an Event Tracing for Windows (ETW) event to be collected during profiling. ETW events are collected in a separate (.etl) file.

2. Attach the profiler to the target application by typing the following command:

   VSPerfCmd /attach :{PID|ProcName}

   PID specifies the process ID of the target application. You can view the process IDs of all running processes in Windows Task Manager.

Control data collection

While 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. By controlling data collection, you can collect data for a specific part of program execution, such as the starting or shutting down of the application.

To start and stop data collection

• The pairs of options in the following table 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 the process ID (PID) specifies.
  /attach :{PID|ProcName} /detach[:{PID|ProcName}]	/attach starts to collect data for the process that the process ID (PID) or process name (ProcName) specifies. /detach stops data collection for the specified process or for all processes if no process is specified.

End the profiling session

To end a profiling session, the profiler must not be collecting data. You can stop collecting data from an application that is profiled with the sampling method by closing the application or by invoking the VSPerfCmd /detach option. You then invoke the VSPerfCmd /shutdown option to turn the profiler off and close the profiling data file.

To end a profiling session

1. Detach the profiler from the target application by closing it or by typing the following command:

   VSPerfCmd /detach

2. Shut down the profiler by typing the following command:

   VSPerfCmd /shutdown