Fixed an initialization problem of the ReadWriteLock pointed out by geist, also added a comment on how the ownership is used when doing read locking. Thanks!

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@21314 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/kernel/file_systems/bfs/Lock.h

@@ -1,12 +1,15 @@
-/* Lock - simple semaphores, read/write lock implementation
- * Roughly based on a Be sample code written by Nathan Schrenk.
+/*
  *
- * Copyright 2001-2006, Axel Dörfler, [email protected].
+ * Copyright 2001-2007, Axel Dörfler, [email protected].
  * This file may be used under the terms of the MIT License.
  */
 #ifndef LOCK_H
 #define LOCK_H
 
+/*!	Simple semaphores, read/write lock implementation
+	Roughly based on a Be sample code written by Nathan Schrenk.
+*/
+
 #include "system_dependencies.h"
 
 #include "Utility.h"
@@ -333,11 +336,16 @@ class ReadWriteLock {
 class ReadWriteLock {
 	public:
 		ReadWriteLock(const char *name)
+			:
+			fOwner(-1)
 		{
 			Initialize(name);
 		}
 
 		ReadWriteLock()
+			:
+			fSemaphore(-1),
+			fOwner(-1)
 		{
 		}
 
@@ -362,6 +370,7 @@ class ReadWriteLock {
 
 		status_t Lock()
 		{
+			// This allows nested locking when holding a write lock
 			thread_id currentThread = find_thread(NULL);
 			if (currentThread == fOwner) {
 				fOwnerCount++;