// ------------------------------------------------------
//
// Private Methods
//
// ------------------------------------------------------
#region Private Methods
// Infinite loop. Wait for queue items to be processed.
private void WaitForWork()
{
SafeWaitHandle handle = _ev.SafeWaitHandle;
NativeMethods.MSG msg = new NativeMethods.MSG();
while (true)
{
try
{
// pump any messages
while (UnsafeNativeMethods.PeekMessage(ref msg, IntPtr.Zero, 0, 0, NativeMethods.PM_REMOVE))
{
if (msg.message == NativeMethods.WM_QUIT)
{
break;
}
Misc.DispatchMessage(ref msg);
}
// do any work items in the queue
// It's possible items could be enqueued between when we check for the count
// and dequeue but the event is set then and we'll come back into DrainQueue.
// (note: don't use a for loop here because as the counter is incremented
// Count is decremented and we'll only process half the queue)
while (_q.Count > 0)
{
// pull an item off the queue, process, then clear it
QueueItem item = (QueueItem)_q.Dequeue();
item.Process();
}
int result = Misc.MsgWaitForMultipleObjects(handle, false, NativeMethods.INFINITE, NativeMethods.QS_ALLINPUT);
if (result == NativeMethods.WAIT_FAILED || result == NativeMethods.WAIT_TIMEOUT)
{
Debug.Assert(false, "MsgWaitForMultipleObjects failed while WaitForWork");
break;
}
}
catch (Exception e)
{
if (Misc.IsCriticalException(e))
{
throw;
}
// Might happen when if the hwnd goes away between the peek and the dispatch
}
//
}
}
