How to: Flag and Unflag Threads (C#, Visual Basic, C++)
Applies to: 
Visual Studio 
Visual 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
You can flag a thread that you want to give special attention by marking it with an icon in the Threads, Parallel Stacks (thread view), Parallel Watch, and GPU Threads windows. This icon can help you and others distinguish flagged threads from other threads.
Flagged threads also receive special treatment in the Thread list on the Debug Location toolbar and in the other multithreaded debugging windows. You can show all threads or only flagged threads in the Thread list or in the other windows.
To flag or unflag a thread
- In the Threads or Parallel Watch window, find the thread you are interested in and click the flag icon to select or clear the flag.
- In the Parallel Stacks window, right-click on a thread or group of threads and select Flag / <thread> or Unflag / <thread>.
To unflag all threads
- In the Threads window, right-click any thread and then click Unflag All Threads.
- In the Parallel Watch window, select all flagged threads, then right-click and select Unflag.
To display only flagged threads
- Choose the Show Flagged Threads Only button in one of the multithreaded debugging windows.
To flag Just My Code
On the toolbar at the top of the Threads window, click the flag icon.
In the drop-down list, click Flag Just My Code.
To flag threads that are associated with selected modules
On the toolbar of the Threads window, click the flag icon.
In the drop-down list, click Flag Custom Module Selection.
In the Select Modules dialog box, select the modules that you want.
(Optional) In the Search box, type a string to search for specific modules.
Click OK.