WakeMainThread: TNotifyEvent = nil;
extern DELPHI_PACKAGE TNotifyEvent WakeMainThread;
Represents a method (event handler) that is forced into the main thread's queue.
Assign a method to WakeMainThread before calling a thread's Synchronize method. When you call a thread's Synchronize method, it calls the method assigned to WakeMainThread once it has obtained a lock on the main GUI thread. This allows other threads to quickly synchronize with the GUI thread even if no events are being processed due to an idle state.