545 /** Mutex so that only one thread can communicate with the main program

   546  * at any given time */

   547 static ThreadMsg _message = 0;

   548 

   549 static inline void OTTD_ReleaseMutex(void) {_message = 0;}

   550 static inline ThreadMsg OTTD_PollThreadEvent(void) {return _message;}

   551 

   552 /** Called by running thread to execute some action in the main game.

   553  * It will stall as long as the mutex is not freed (handled) by the game */

   554 void OTTD_SendThreadMessage(ThreadMsg msg)

   555 {

   556 	while (_message != 0) CSleep(10);

   557 

   558 	_message = msg;

   559 }

   560 

   561 

   562 /** Handle the user-messages sent to us

   563  * @param message message sent

   564  */

   565 void ProcessSentMessage(ThreadMsg message)

   566 {

   567 	switch (message) {

   568 		case MSG_OTTD_SAVETHREAD_START: SaveFileStart(); break;

   569 		case MSG_OTTD_SAVETHREAD_DONE:  SaveFileDone(); break;

   570 		case MSG_OTTD_SAVETHREAD_ERROR: SaveFileError(); break;

   571 		default: NOT_REACHED();

   572 	}

   573 

   574 	OTTD_ReleaseMutex(); // release mutex so that other threads, messages can be handled

   575 }

   576 

   949 	ThreadMsg message;

   950 

   951 

   952 	if ((message = OTTD_PollThreadEvent()) != 0) ProcessSentMessage(message);