Ignore ThreadAbortException when logging exceptions

Question

What's the correct way of ignoring ThreadAbortException when logging exceptions?

Is it safe to just catch it in an empty catch block to make it disappear?

Answer 1

If you need to stop a ThreadAbortException propogating further up the call stack, you can call Thread.ResetAbort. So try something like:

try
{
  // some code
}
catch (ThreadAbortException ex)
{
  // do some logging
  Thread.ResetAbort();
}

As for "correct" - that depends on your usage scenario. I'd generally be cautious about catching these unless you understand exactly why it has been raised. In escence it is a "stop now, quickly, and drop what you are doing" signal. Resetting it and going on to do further processing should be done with caution.

Answer 2

Employ two catch blocks: one for ThreadAbortException and one for the rest, for example:

void MainLoop()
{   bool workdone;
    try
    {   while( IsWorking ) // cross-thread volatile variable
        {   workdone = Process();
            if( !workdone )
            {   Thread.Sleep( 500 );  }
        }
    }
    catch( ThreadAbortException )
    {   // Forced termination. Exit silently.
    }
    catch (Exception e)
    {   LogError( e );  }
}