How to tie a background thread to the lifetime of an object?

Question

I want to create a background thread that's owned by an object. When that object is no longer needed, so is its background thread.

pseudo code of what I currently have:

ResetEvent _isCanceled
ResetEvent _hasWork
ThreadSafeQueue _workItems

Init()
  new BackgroundThread(ThreadLoop).Start()

AddWork(work)
  _workItems.Enqueue(work)
  _hasWork.Set()

Dispose()
  _isCanceled.Set()

ThreadLoop()
  while(!_isCanceled)
    if(_hasWork)
      Execute(_workItems.Dequeue())
    if(_workItems.IsEmpty)
      _hasWork.Reset()
    WaitHandle.WaitAny(_isCanceled, _hasWork)

The problem is that if someone (not me of course) forgets to call Dispose(), the thread will never be stopped. What I understood about Finalize is that you can't refer to any members, because you must assume they are null-ed already.

So how can I stop the background thread if the owning object is or gets gc-ed?

Answer 1

Finalize is right place to do this. Just check is not it null.