* Added an atomic_pointer_set() template function to util/atomic.h.

* Made the pointers const.
* Changed how the ARP module maintains its arp_entry::request_buffer: it
  now uses the atomic_pointer*() functions to make sure there is no race
  condition, and it's deleted only once.
* Getting an ARP entry would return uninitialized data, if the entry hadn't
  been resolved yet.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25263 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/util/atomic.h

@@ -14,8 +14,8 @@
 #ifdef __cplusplus
 
 template<typename PointerType> PointerType*
-atomic_pointer_test_and_set(PointerType** _pointer, PointerType* set,
-	PointerType* test)
+atomic_pointer_test_and_set(PointerType** _pointer, const PointerType* set,
+	const PointerType* test)
 {
 #if LONG_MAX == INT_MAX
 	return (PointerType*)atomic_test_and_set((vint32*)_pointer, (int32)set,
@@ -26,6 +26,17 @@ atomic_pointer_test_and_set(PointerType** _pointer, PointerType* set,
 #endif
 }
 
+
+template<typename PointerType> PointerType*
+atomic_pointer_set(PointerType** _pointer, const PointerType* set)
+{
+#if LONG_MAX == INT_MAX
+	return (PointerType*)atomic_set((vint32*)_pointer, (int32)set);
+#else
+	return (PointerType*)atomic_set64((vint64*)_pointer, (int64)set);
+#endif
+}
+
 #endif	// __cplusplus
 
 #endif	/* _KERNEL_UTIL_ATOMIC_H */