From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 25 Dec 2015 10:13:57 +0000 (+0200)
Subject: Refactor Timer::tick
X-Git-Url: http://git.tdb.fi/?p=libs%2Fcore.git;a=commitdiff_plain;h=ac26a7e3db27d27ea322ccc17bb093b348b30ae8

Refactor Timer::tick

The previous version had some bugs: the blocking flag was not reset and
it might have tried to execute a canceled (and thus deleted) slot.
---

diff --git a/source/time/timer.cpp b/source/time/timer.cpp
index f26900b..7c9567e 100644
--- a/source/time/timer.cpp
+++ b/source/time/timer.cpp
@@ -1,4 +1,5 @@
 #include <algorithm>
+#include <msp/core/raii.h>
 #include "timer.h"
 #include "utils.h"
 
@@ -60,30 +61,27 @@ void Timer::tick(bool block)
 		MutexLock l(mutex);
 		while(1)
 		{
-			if(slots.empty())
+			TimeStamp stamp;
+			TimeStamp t = now();
+			if(!slots.empty())
 			{
-				if(block)
-				{
-					blocking = true;
-					mutex.unlock();
-					sem.wait();
-					mutex.lock();
-				}
-				else
-					return;
+				next = slots.begin()->slot;
+				stamp = next->get_timeout();
+				if(stamp<=t)
+					break;
 			}
 
-			next = slots.begin()->slot;
-			const TimeStamp &stamp = next->get_timeout();
-			const TimeStamp t = now();
-			if(stamp<=t)
-				break;
-			else if(block)
+			if(block)
 			{
-				blocking = true;
+				SetFlag setf(blocking);
 				mutex.unlock();
-				sem.wait(stamp-t);
+				if(stamp)
+					sem.wait(stamp-t);
+				else
+					sem.wait();
 				mutex.lock();
+				// The slots may have changed while waiting so check again
+				continue;
 			}
 			else
 				return;