Next version of the threading queue deadlock fix.

We now just use the read/write counters, as suggested by Gilbert.

src/threading/Manager.cc

@@ -82,17 +82,7 @@ double Manager::NextTimestamp(double* network_time)
 		{
 		MsgThread* t = *i;
 
-		// We check here if there's something ready to read from the
+		if ( (*i)->MightHaveOut() && ! t->Killed() )
-		// queue. Normally the queue will tell us that reliably via
-		// MightHaveOut() because we keep sending heartbeats that
-		// will ensure that the method will eventually return true.
-		// However, when running without network source and without
-		// any communication, the timer_manager's time will always
-		// remain at 1.0, which means that heartbeats will never be
-		// triggered. In that case, we make sure to still process our
-		// threads from time to time.
-		if ( ((*i)->MightHaveOut() && ! t->Killed())
-		     || (timer_mgr->Time() == 1.0 && random() % 10000 == 0) )
 			return timer_mgr->Time();
 		}
 

src/threading/Queue.h

@@ -69,7 +69,7 @@ public:
 	 * it is empty. In other words, this method helps to avoid locking the queue
 	 * frequently, but doesn't allow you to forgo it completely.
 	 */
-	bool MaybeReady() { return (read_ptr != write_ptr); }
+	bool MaybeReady() { return (num_reads != num_writes); }
 
 	/** Wake up the reader if it's currently blocked for input. This is
 	 primarily to give it a chance to check termination quickly.