Add comments on the definition of SPIN_LOCK_RELEASED & SPIN_LOCK_ACQUIRED

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@2522 6f19259b-4bc3-4df7-8a09-765794883524

diff --git a/MdePkg/Library/BaseLib/Synchronization.c b/MdePkg/Library/BaseLib/Synchronization.c
index 225453149d30a476187250b076f0b53ffc19c520..59919a7f03b1ac1955d1075fd30585d060e10c94 100644 (file)
--- a/MdePkg/Library/BaseLib/Synchronization.c
+++ b/MdePkg/Library/BaseLib/Synchronization.c
@@ -16,6 +16,10 @@
 \r
 #include "BaseLibInternals.h"\r
 \r
+//\r
+// SPIN_LOCK_RELEASED & SPIN_LOCK_ACQUIRED should belong to type "SPIN_LOCK".\r
+// Here we use type-case "UINTN" to avoid "volatile" modifier on const integers.\r
+//\r
 #define SPIN_LOCK_RELEASED          ((UINTN) 1)\r
 #define SPIN_LOCK_ACQUIRED          ((UINTN) 2)\r
 \r