How do I determine which are the foreground .NET threads from WinDBG ?

Question

How do I determine which are the foreground .NET threads from WinDBG ? Using the !threads command the SOS extenstion tells us the count of the foreground threads but not which ones.

Answer 1

The state flag in the !threads output holds a lot of information. If the 0x00000200 flag is set the thread is a background thread.

In SOS for .NET 4 and PSSCOR2, there's a !threadstate command, that will list the texts for a given flag value. If you don't have that, there's an overview of the flags in the rotor source code and in Debugging .NET 2.0 applications by John Robbins.

Answer 2

You can use the thread state values given in this link and find out if a thread is a background thread or not.

TS_Background 0x00000200 Thread is a background thread