ThreadAbortException

Question

Let\'s say we have some code like this running in the separate thread:

private static void ThreadFunc() {
    ulong counter = 0;

    while (true) {

                


        

Answer 1

Actually, ThreadAbortException is special in case it's thrown by CLR or Thread.Abort method. Compare output:

• Slightly modified example (added Console.WriteLine) from Joe Duffy's "Concurrent Programming on Windows". It throws the exception by Thread.CurrentThread.Abort:

  
  try
  {
      try
      {
          Thread.CurrentThread.Abort();
      }
      catch (ThreadAbortException)
      {
          Console.WriteLine("First");
          //Try to swallow it.
      } //CLR automatically reraises the exception here .
  }
  catch (ThreadAbortException)
  {
      Console.WriteLine("Second");
      Thread.ResetAbort();
      //Try to swallow it again .
  } //The in - flight abort was reset , so it is not reraised again .
  
  
  

  Output:

  First
  Second
  

• Modify previous example to use different approach of ThreadAbortException instance creation:

  
  try
  {
      try
      {
          // get non-public constructor
          var cstor = typeof(ThreadAbortException)
              .GetConstructor(BindingFlags.Instance | BindingFlags.NonPublic, null, Type.EmptyTypes, null);
          // create ThreadAbortException instance
          ThreadAbortException ex = cstor.Invoke(null) as ThreadAbortException;
  
          // throw..
          throw ex;
      }
      catch (ThreadAbortException)
      {
          Console.WriteLine("First");
      } 
  }
  catch (ThreadAbortException)
  {
      Console.WriteLine("Second");
      Thread.ResetAbort();
  } 
  

  Output:

  First
  

It seems like Thread's methods call native code internally which makes raised exception specific.