ThreadAbortException Class

Definition

Namespace:

System.Threading

Assembly:

System.Threading.Thread.dll

Source:

ThreadAbortException.cs

The exception that is thrown when a call is made to the Abort(Object) method. This class cannot be inherited.

public ref class ThreadAbortException sealed : SystemException

public sealed class ThreadAbortException : SystemException

type ThreadAbortException = class
    inherit SystemException

Public NotInheritable Class ThreadAbortException
Inherits SystemException

Inheritance

Object

Exception

SystemException

ThreadAbortException

Examples

The following example demonstrates aborting a thread. The thread that receives the ThreadAbortException uses the ResetAbort method to cancel the abort request and continue executing.

using namespace System;
using namespace System::Threading;
using namespace System::Security::Permissions;
ref class ThreadWork
{
public:
   static void DoWork()
   {
      try
      {
         for ( int i = 0; i < 100; i++ )
         {
            Console::WriteLine( "Thread - working." );
            Thread::Sleep( 100 );

         }
      }
      catch ( ThreadAbortException^ e ) 
      {
         Console::WriteLine( "Thread - caught ThreadAbortException - resetting." );
         Console::WriteLine( "Exception message: {0}", e->Message );
         Thread::ResetAbort();
      }

      Console::WriteLine( "Thread - still alive and working." );
      Thread::Sleep( 1000 );
      Console::WriteLine( "Thread - finished working." );
   }

};

int main()
{
   ThreadStart^ myThreadDelegate = gcnew ThreadStart( ThreadWork::DoWork );
   Thread^ myThread = gcnew Thread( myThreadDelegate );
   myThread->Start();
   Thread::Sleep( 100 );
   Console::WriteLine( "Main - aborting my thread." );
   myThread->Abort();
   myThread->Join();
   Console::WriteLine( "Main ending." );
}

using System;
using System.Threading;
using System.Security.Permissions;

public class ThreadWork {
    public static void DoWork() {
        try {
            for(int i=0; i<100; i++) {
                Console.WriteLine("Thread - working.");
                Thread.Sleep(100);
            }
        }
        catch(ThreadAbortException e) {
            Console.WriteLine("Thread - caught ThreadAbortException - resetting.");
            Console.WriteLine("Exception message: {0}", e.Message);
            Thread.ResetAbort();
        }
        Console.WriteLine("Thread - still alive and working.");
        Thread.Sleep(1000);
        Console.WriteLine("Thread - finished working.");
    }
}

class ThreadAbortTest {
    public static void Main() {
        ThreadStart myThreadDelegate = new ThreadStart(ThreadWork.DoWork);
        Thread myThread = new Thread(myThreadDelegate);
        myThread.Start();
        Thread.Sleep(100);
        Console.WriteLine("Main - aborting my thread.");
        myThread.Abort();
        myThread.Join();
        Console.WriteLine("Main ending.");
    }
}

Imports System.Threading
Imports System.Security.Permissions


Public Class ThreadWork
   Public Shared Sub DoWork()
      Try
         Dim i As Integer
         For i = 0 To 99
            Console.WriteLine("Thread - working.")
            Thread.Sleep(100)
         Next i
      Catch e As ThreadAbortException
         Console.WriteLine("Thread - caught ThreadAbortException - resetting.")
         Console.WriteLine("Exception message: {0}", e.Message)
         Thread.ResetAbort()
      End Try
      Console.WriteLine("Thread - still alive and working.")
      Thread.Sleep(1000)
      Console.WriteLine("Thread - finished working.")
   End Sub
End Class


Class ThreadAbortTest
   Public Shared Sub Main()
      Dim myThreadDelegate As New ThreadStart(AddressOf ThreadWork.DoWork)
      Dim myThread As New Thread(myThreadDelegate)
      myThread.Start()
      Thread.Sleep(100)
      Console.WriteLine("Main - aborting my thread.")
      myThread.Abort()
      myThread.Join()
      Console.WriteLine("Main ending.")
   End Sub
End Class

This code produces the following output:

Thread - working.  
Main - aborting my thread.  
Thread - caught ThreadAbortException - resetting.  
Exception message: Thread was being aborted.  
Thread - still alive and working.  
Thread - finished working.  
Main ending.  

Remarks

When a call is made to the Abort method to destroy a thread, the common language runtime throws a ThreadAbortException on .NET Framework. ThreadAbortException is a special exception that can be caught, but it will automatically be raised again at the end of the catch block. When this exception is raised, the runtime executes all the finally blocks before ending the thread. Because the thread can do an unbounded computation in the finally blocks or call Thread.ResetAbort to cancel the abort, there is no guarantee that the thread will ever end. If you want to wait until the aborted thread has ended, you can call the Thread.Join method. Join is a blocking call that does not return until the thread actually stops executing.

Note

.NET Core and .NET 5+ only: Even though this type exists in .NET Core and .NET 5+, since Abort is not supported, the common language runtime won't ever throw ThreadAbortException.

Note

When the common language runtime (CLR) stops background threads after all foreground threads in a managed executable have ended, it does not use Thread.Abort. Therefore, you cannot use ThreadAbortException to detect when background threads are being terminated by the CLR.

ThreadAbortException uses HRESULT COR_E_THREADABORTED, which has the value 0x80131530.

Note

The value of the inherited Data property is always null.

Properties

Data	Gets a collection of key/value pairs that provide additional user-defined information about the exception. (Inherited from Exception)
ExceptionState	Gets an object that contains application-specific information related to the thread abort.
HelpLink	Gets or sets a link to the help file associated with this exception. (Inherited from Exception)
HResult	Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception. (Inherited from Exception)
InnerException	Gets the Exception instance that caused the current exception. (Inherited from Exception)
Message	Gets a message that describes the current exception. (Inherited from Exception)
Source	Gets or sets the name of the application or the object that causes the error. (Inherited from Exception)
StackTrace	Gets a string representation of the immediate frames on the call stack. (Inherited from Exception)
TargetSite	Gets the method that throws the current exception. (Inherited from Exception)

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetBaseException()	When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions. (Inherited from Exception)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetObjectData(SerializationInfo, StreamingContext)	Obsolete. When overridden in a derived class, sets the SerializationInfo with information about the exception. (Inherited from Exception)
GetType()	Gets the runtime type of the current instance. (Inherited from Exception)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Creates and returns a string representation of the current exception. (Inherited from Exception)

Events

SerializeObjectState

Obsolete. Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception. (Inherited from Exception)

See also

• Thread
• Abort(Object)
• Destroying threads