Added a listener mechanism to the scheduler (ATM only for scheduler_simple).

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30242 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/kscheduler.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008, Ingo Weinhold, [email protected].
+ * Copyright 2008-2009, Ingo Weinhold, [email protected].
  * Copyright 2005, Axel Dörfler, [email protected].
  * Distributed under the terms of the MIT License.
  */
@@ -12,6 +12,28 @@
 
 struct scheduling_analysis;
 struct thread;
+struct SchedulerListener;
+
+
+#ifdef __cplusplus
+
+#include <util/DoublyLinkedList.h>
+
+struct SchedulerListener : DoublyLinkedListLinkImpl<SchedulerListener> {
+	virtual						~SchedulerListener();
+
+	virtual	void				ThreadEnqueuedInRunQueue(
+									struct thread* thread) = 0;
+	virtual	void				ThreadRemovedFromRunQueue(
+									struct thread* thread) = 0;
+	virtual	void				ThreadScheduled(struct thread* oldThread,
+									struct thread* newThread) = 0;
+};
+
+typedef DoublyLinkedList<SchedulerListener> SchedulerListenerList;
+extern SchedulerListenerList gSchedulerListeners;
+
+#endif	// __cplusplus
 
 
 struct scheduler_ops {
@@ -29,7 +51,7 @@ struct scheduler_ops {
 	// called when a thread structure is freed - freeing up any allocated
 	// mem on the scheduler's part should be done here
 	void (*on_thread_destroy)(struct thread* thread);
-	
+
 	void (*start)(void);
 };
 
@@ -52,6 +74,9 @@ extern struct scheduler_ops* gScheduler;
 extern "C" {
 #endif
 
+void scheduler_add_listener(struct SchedulerListener* listener);
+void scheduler_remove_listener(struct SchedulerListener* listener);
+
 void scheduler_init(void);
 
 status_t _user_analyze_scheduling(bigtime_t from, bigtime_t until, void* buffer,