fix "trickles[id].period << scale" overflow

mmaroti · mmaroti · commit 11ff9646f674 · 2009-07-16T13:00:08.000Z
git-svn-id: http://tinyos-main.googlecode.com/svn/trunk@4641 285f258d-8064-b571-fbc6-9656dc998e90
diff --git a/tos/lib/net/TrickleTimerImplP.nc b/tos/lib/net/TrickleTimerImplP.nc
@@ -1,4 +1,4 @@
-// $Id: TrickleTimerImplP.nc,v 1.5 2007-07-30 00:42:00 scipio Exp $
+// $Id: TrickleTimerImplP.nc,v 1.6 2009-07-16 13:00:08 mmaroti Exp $
 /*
  * "Copyright (c) 2006 Stanford University. All rights reserved.
  *
@@ -262,7 +262,7 @@ implementation {
     rval = call Random.rand16() % (trickles[id].period << (scale - 1));
     newTime += rval;
     
-    trickles[id].remainder = (trickles[id].period << scale) - newTime;
+    trickles[id].remainder = (((uint32_t)trickles[id].period) << scale) - newTime;
     trickles[id].time += newTime;
     dbg("Trickle,TrickleTimes", "Generated time for %hhu with period %hu (%u) is %u (%i + %hu)\n", id, trickles[id].period, (uint32_t)trickles[id].period << scale, trickles[id].time, (trickles[id].period << (scale - 1)), rval);
   }

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-// $Id: TrickleTimerImplP.nc,v 1.5 2007-07-30 00:42:00 scipio Exp $`
	`1`	`+// $Id: TrickleTimerImplP.nc,v 1.6 2009-07-16 13:00:08 mmaroti Exp $`
`2`	`2`	`/*`
`3`	`3`	`* "Copyright (c) 2006 Stanford University. All rights reserved.`
`4`	`4`	`*`
`@@ -262,7 +262,7 @@ implementation {`
`262`	`262`	`rval = call Random.rand16() % (trickles[id].period << (scale - 1));`
`263`	`263`	`newTime += rval;`
`264`	`264`
`265`		`- trickles[id].remainder = (trickles[id].period << scale) - newTime;`
	`265`	`+ trickles[id].remainder = (((uint32_t)trickles[id].period) << scale) - newTime;`
`266`	`266`	`trickles[id].time += newTime;`
`267`	`267`	`dbg("Trickle,TrickleTimes", "Generated time for %hhu with period %hu (%u) is %u (%i + %hu)\n", id, trickles[id].period, (uint32_t)trickles[id].period << scale, trickles[id].time, (trickles[id].period << (scale - 1)), rval);`
`268`	`268`	`}`