Threads synchronization

Hi!

Please consult me on the following question:

1. There is main GUI thread, two buttons Start and ReStart

2. ManualResetEvent is used to stop the working thread 

3. "Start" creates and starts the thread

   {
      workThread = new Thread(() => DoWork());
      workThread.Start();
   }

  void DoWork()
  {         
     while (true)
     {              
        Thread.Sleep(1000);

         MethodInvoker methodInvoker = delegate() { "Update GUI" };
         this.Invoke(methodInvoker);

         if (manualResetEvent.WaitOne(0))
         {                    
            break;
         }                                                                
      }            
   }

4. ReStart should stop the thread and start new one with the same DoWork method.

My question is how correctly stop current thread and start new one?

{
  manualResetEvent.Set();

  //Incorrect because first thread can be still alive

  workThread = new Thread(() => DoWork());
  workThread.Start();
}

{
  manualResetEvent.Set();

  //Incorrect because there will be a deadlock on GUI thread
  workThread.Join();    

  workThread = new Thread(() => DoWork());
  workThread.Start();
}

Please advice correct implementation (maybe using tasks or other stuff from TPL)

Thank you

Alexander