Use InterlockedExchangeAdd() instead of InterlockedAdd() on Windows

InterlockedAdd() is not supported on all the platforms we wish to
support.  However, InterlockedExchangeAdd() is.  The two
functions are semantically similar with the exception that
InterlockedExchangeAdd() returns the initial value of the object
being modified while InterlockedAdd() returns the resulting
value.  Since the return value of the rx_MutexAdd() macro is
unused, this is irrelevant.

Reviewed-on: http://gerrit.openafs.org/98
Verified-by: Jeffrey Altman <jaltman@openafs.org>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>

diff --git a/src/rx/rx.h b/src/rx/rx.h
index ba9537f166a7d35d687b204d068e252c1c3798f7..5e2550bfc8d4024da250bf6d49900d4e52a3d291 100644 (file)
--- a/src/rx/rx.h
+++ b/src/rx/rx.h
@@ -1087,7 +1087,7 @@ typedef struct rx_interface_stat {
 extern int rx_DumpCalls(FILE *outputFile, char *cookie);
 
 #define rx_MutexIncrement(object, mutex) InterlockedIncrement(&object)
-#define rx_MutexAdd(object, addend, mutex) InterlockedAdd(&object, addend)
+#define rx_MutexAdd(object, addend, mutex) InterlockedExchangeAdd(&object, addend)
 #define rx_MutexDecrement(object, mutex) InterlockedDecrement(&object)
 #define rx_MutexAdd1Increment2(object1, addend, object2, mutex) \
     do { \