fix empty queue case

diff --git a/tos/system/RoundRobinResourceQueueC.nc b/tos/system/RoundRobinResourceQueueC.nc
index b6d5565beb1ccadf288f9d224fd6196a16a15e35..d2805a6427b2ad2966930aa8fb5ac96ffdf82737 100644 (file)
--- a/tos/system/RoundRobinResourceQueueC.nc
+++ b/tos/system/RoundRobinResourceQueueC.nc
@@ -36,9 +36,12 @@ generic module RoundRobinResourceQueueC(uint8_t size) {
   }
 }
 implementation {
-  enum {NO_ENTRY = 0xFF};
+  enum {
+    NO_ENTRY = 0xFF,
+    SIZE = size ? (size - 1) / 8 + 1 : 0
+  };
 
-  uint8_t resQ[(size-1)/8 + 1];
+  uint8_t resQ[SIZE];
   uint8_t last = 0;
 
   void clearEntry(uint8_t id) {