From 12ab8ebcade3a0ecd693c71e63e04cc857111776 Mon Sep 17 00:00:00 2001
From: klueska <klueska>
Date: Fri, 24 Aug 2007 16:10:09 +0000
Subject: [PATCH] Fixed bug that allowed isOwner() to return false ownership
 between pending requests being granted.

---
 tos/system/ArbiterP.nc       | 13 +++++++++++--
 tos/system/SimpleArbiterP.nc |  8 ++++++--
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/tos/system/ArbiterP.nc b/tos/system/ArbiterP.nc
index 9650a707..872b71f6 100644
--- a/tos/system/ArbiterP.nc
+++ b/tos/system/ArbiterP.nc
@@ -66,6 +66,7 @@ implementation {
 
   enum {RES_CONTROLLED, RES_GRANTING, RES_IMM_GRANTING, RES_BUSY};
   enum {default_owner_id = default_owner_id};
+  enum {NO_RES = 0xFF};
 
   uint8_t state = RES_CONTROLLED;
   norace uint8_t resId = default_owner_id;
@@ -144,6 +145,10 @@ implementation {
     Check if the Resource is currently in use
   */    
   async command bool ArbiterInfo.inUse() {
+    atomic {
+      if (state == RES_CONTROLLED)
+        return FALSE;
+    }
     return TRUE;
   }
 
@@ -153,7 +158,11 @@ implementation {
     will be 0xFF
   */      
   async command uint8_t ArbiterInfo.userId() {
-    atomic return resId;
+    atomic {
+      if(state != RES_BUSY)
+        return NO_RES;
+      return resId;
+    }
   }
 
   /**
@@ -161,7 +170,7 @@ implementation {
    */      
   async command uint8_t Resource.isOwner[uint8_t id]() {
     atomic {
-      if(resId == id) return TRUE;
+      if(resId == id && state == RES_BUSY) return TRUE;
       else return FALSE;
     }
   }
diff --git a/tos/system/SimpleArbiterP.nc b/tos/system/SimpleArbiterP.nc
index c5e82f29..91d883a0 100644
--- a/tos/system/SimpleArbiterP.nc
+++ b/tos/system/SimpleArbiterP.nc
@@ -134,7 +134,11 @@ implementation {
     will be 0xFF
   */      
   async command uint8_t ArbiterInfo.userId() {
-    atomic return resId;
+    atomic {
+      if(state != RES_BUSY)
+        return NO_RES;
+      return resId;
+    }
   }
 
   /**
@@ -142,7 +146,7 @@ implementation {
    */      
   async command uint8_t Resource.isOwner[uint8_t id]() {
     atomic {
-      if(resId == id) return TRUE;
+      if(resId == id && state == RES_BUSY) return TRUE;
       else return FALSE;
     }
   }
-- 
2.39.2