Question

I have a C# application which is hitting an ObjectDisposedException with the message

Safe handle has been closed

This happens as soon as I launch the application.

Sadly the stack trace is really unhelpful (see below). Is there any way for me to determine what call was being attempted asynchronously here?

Does DoAsyncCall() really imply an async method call?

mscorlib.dll!System.Threading.EventWaitHandle.Set() + 0xe bytes
mscorlib.dll!System.Runtime.Remoting.Messaging.AsyncResult.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage
msg) + 0x12f bytes
mscorlib.dll!System.Runtime.Remoting.Messaging.StackBuilderSink.AsyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage
msg, System.Runtime.Remoting.Messaging.IMessageSink replySink =
{System.Runtime.Remoting.Messaging.AsyncResult}) + 0x279 bytes
mscorlib.dll!System.Runtime.Remoting.Proxies.AgileAsyncWorkerItem.DoAsyncCall()
+ 0x32 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.AgileAsyncWorkerItem.ThreadPoolCallBack(object
o) + 0x28 bytes
mscorlib.dll!System.Threading._ThreadPoolWaitCallback.WaitCallback_Context(object
state) + 0x2f bytes
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext
executionContext, System.Threading.ContextCallback callback, object
state) + 0x6f bytes
mscorlib.dll!System.Threading._ThreadPoolWaitCallback.PerformWaitCallbackInternal(System.Threading._ThreadPoolWaitCallback
tpWaitCallBack) + 0x53 bytes
mscorlib.dll!System.Threading._ThreadPoolWaitCallback.PerformWaitCallback(object
state) + 0x59 bytes

Answer 1

The problem was caused by my use of a using(){} block.

    using (WaitHandle handle = asyncResponse.AsyncWaitHandle)
    {
      asyncResponse.AsyncWaitHandle.WaitOne();
      string response = asyncRequest.EndInvoke(asyncResponse);
      asyncResponse.AsyncWaitHandle.Close();
      return response;
    } 

When the calling thread is interrupted the using block is still calling Close on the WaitHandle.