Introducing - the check if a thread queue might have data. Without locks. Who needs those anyways.

src/threading/Manager.cc

@@ -83,6 +83,12 @@ double Manager::NextTimestamp(double* network_time)
 		// is due), we want to check for more asap.
 		return timer_mgr->Time();
 	
+	for ( msg_thread_list::iterator i = msg_threads.begin(); i != msg_threads.end(); i++ )
+		{
+			if ( (*i)->MightHaveOut() ) 
+				return timer_mgr->Time();
+		}
+
 	return -1.0;
 	}
 

src/threading/MsgThread.h

@@ -261,6 +261,12 @@ private:
 	 */
 	bool HasOut()	{ return queue_out.Ready(); }
 
+	/**
+	 * Returns true if there might be at least one message pending for the main
+	 * thread.
+	 */
+	bool MightHaveOut() { return queue_out.MaybeReady(); }
+
 	Queue<BasicInputMessage *> queue_in;
 	Queue<BasicOutputMessage *> queue_out;
 

src/threading/Queue.h

@@ -53,6 +53,11 @@ public:
 	 */
 	bool Ready();
 
+	/**
+	 * Returns true if the next Get() operation might succeed.
+	 */
+	bool MaybeReady() { return ( ( read_ptr - write_ptr) != 0 ); }
+
 	/**
 	 * Returns the number of queued items not yet retrieved.
 	 */