// One of TCL.QUEUE_TAIL, TCL.QUEUE_HEAD or TCL.QUEUE_MARK.
public void QueueEvent(TclEvent evt, TCL.QUEUE position)
{
lock (this)
{
evt.notifier = this;
if (position == TCL.QUEUE.TAIL)
{
// Append the event on the end of the queue.
evt.next = null;
if (_firstEvent == null)
{
_firstEvent = evt;
}
else
{
_lastEvent.next = evt;
}
_lastEvent = evt;
}
else if (position == TCL.QUEUE.HEAD)
{
// Push the event on the head of the queue.
evt.next = _firstEvent;
if (_firstEvent == null)
{
_lastEvent = evt;
}
_firstEvent = evt;
}
else if (position == TCL.QUEUE.MARK)
{
// Insert the event after the current marker event and advance the marker to the new event.
if (_markerEvent == null)
{
evt.next = _firstEvent;
_firstEvent = evt;
}
else
{
evt.next = _markerEvent.next;
_markerEvent.next = evt;
}
_markerEvent = evt;
if (evt.next == null)
{
_lastEvent = evt;
}
}
else
{
// Wrong flag.
throw new TclRuntimeError("wrong position \"" + position + "\", must be TCL.QUEUE_HEAD, TCL.QUEUE_TAIL or TCL.QUEUE_MARK");
}
if (Thread.CurrentThread != PrimaryThread)
{
Monitor.PulseAll(this);
}
}
}
// The deleter that checks whether an event should be removed.
public void deleteEvents(IEventDeleter deleter)
{
lock (this)
{
TclEvent servicedEvent = null;
// Handle the special case of deletion of a single event that was just processed by the serviceEvent() method.
if (deleter == this)
{
servicedEvent = _servicedEvent;
if (servicedEvent == null)
{
throw new TclRuntimeError("servicedEvent was not set by serviceEvent()");
}
_servicedEvent = null;
}
for (TclEvent prev = null, evt = _firstEvent; evt != null; evt = evt.next)
{
if ((servicedEvent == null && deleter.DeleteEvent(evt)) || evt == servicedEvent)
{
if (evt == _firstEvent)
{
_firstEvent = evt.next;
}
else
{
prev.next = evt.next;
}
if (evt.next == null)
{
_lastEvent = prev;
}
if (evt == _markerEvent)
{
_markerEvent = prev;
}
if (evt == servicedEvent)
{
servicedEvent = null;
break; // Just service this one event in the special case
}
}
else
{
prev = evt;
}
}
if (servicedEvent != null)
{
throw new TclRuntimeError("servicedEvent was not removed from the queue");
}
}
}
private int _refCount; // Reference count of the notifier. It's used to tell when a notifier is no longer needed.
private Notifier(Thread primaryThread)
{
PrimaryThread = primaryThread;
_firstEvent = null;
_lastEvent = null;
_markerEvent = null;
TimerList = new ArrayList(10);
TimerGeneration = 0;
IdleList = new ArrayList(10);
IdleGeneration = 0;
TimerPending = false;
_refCount = 0;
}
private TclEvent getAvailableEvent(TclEvent skipEvent)
// Indicates that the given event should not
// be returned. This argument can be null.
{
lock (this)
{
TclEvent evt;
for (evt = _firstEvent; evt != null; evt = evt.next)
{
if ((evt.isProcessing == false) && (evt.isProcessed == false) && (evt != skipEvent))
{
return(evt);
}
}
return(null);
}
}
internal int serviceEvent(int flags)
// Indicates what events should be processed.
// May be any combination of TCL.WINDOW_EVENTS
// TCL.FILE_EVENTS, TCL.TIMER_EVENTS, or other
// flags defined elsewhere. Events not
// matching this will be skipped for processing
// later.
{
TclEvent evt;
// No event flags is equivalent to TCL_ALL_EVENTS.
if ((flags & TCL.ALL_EVENTS) == 0)
{
flags |= TCL.ALL_EVENTS;
}
// Loop through all the events in the queue until we find one
// that can actually be handled.
evt = null;
while ((evt = getAvailableEvent(evt)) != null)
{
// Call the handler for the event. If it actually handles the
// event then free the storage for the event. There are two
// tricky things here, both stemming from the fact that the event
// code may be re-entered while servicing the event:
//
// 1. Set the "isProcessing" field to true. This is a signal to
// ourselves that we shouldn't reexecute the handler if the
// event loop is re-entered.
// 2. When freeing the event, must search the queue again from the
// front to find it. This is because the event queue could
// change almost arbitrarily while handling the event, so we
// can't depend on pointers found now still being valid when
// the handler returns.
evt.isProcessing = true;
if (evt.processEvent(flags) != 0)
{
evt.isProcessed = true;
// Don't allocate/grab the monitor for the event unless sync()
// has been called in another thread. This is thread safe
// since sync() checks the isProcessed flag before calling wait.
if (evt.needsNotify)
{
lock (evt)
{
System.Threading.Monitor.PulseAll(evt);
}
}
// Remove this specific event from the queue
_servicedEvent = evt;
deleteEvents(this);
return(1);
}
else
{
// The event wasn't actually handled, so we have to
// restore the isProcessing field to allow the event to be
// attempted again.
evt.isProcessing = false;
}
// The handler for this event asked to defer it. Just go on to
// the next event.
continue;
}
return(0);
}
public bool DeleteEvent(TclEvent evt)
{
throw new TclRuntimeError("The Notifier.deleteEvent() method should not be called");
}
