diff --git a/include/ui/FramebufferNativeWindow.h b/include/ui/FramebufferNativeWindow.h
index 0f4594f..c913355 100644
--- a/include/ui/FramebufferNativeWindow.h
+++ b/include/ui/FramebufferNativeWindow.h
@@ -56,6 +56,9 @@
     status_t setUpdateRectangle(const Rect& updateRect);
     status_t compositionComplete();
     
+    // for debugging only
+    int getCurrentBufferIndex() const;
+
 private:
     friend class LightRefBase<FramebufferNativeWindow>;    
     ~FramebufferNativeWindow(); // this class cannot be overloaded
@@ -77,6 +80,7 @@
     int32_t mNumBuffers;
     int32_t mNumFreeBuffers;
     int32_t mBufferHead;
+    int32_t mCurrentBufferIndex;
     bool mUpdateOnDemand;
 };
     
diff --git a/include/ui/GraphicLog.h b/include/ui/GraphicLog.h
new file mode 100644
index 0000000..f929e6a
--- /dev/null
+++ b/include/ui/GraphicLog.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _UI_GRAPHIC_LOG_H
+#define _UI_GRAPHIC_LOG_H
+
+#include <utils/Singleton.h>
+#include <cutils/compiler.h>
+
+namespace android {
+
+class GraphicLog : public Singleton<GraphicLog>
+{
+    int32_t mEnabled;
+    static void logImpl(int32_t tag, int32_t buffer);
+    static void logImpl(int32_t tag, int32_t identity, int32_t buffer);
+
+public:
+    enum {
+        SF_APP_DEQUEUE_BEFORE   = 60000,
+        SF_APP_DEQUEUE_AFTER    = 60001,
+        SF_APP_LOCK_BEFORE      = 60002,
+        SF_APP_LOCK_AFTER       = 60003,
+        SF_APP_QUEUE            = 60004,
+
+        SF_REPAINT              = 60005,
+        SF_COMPOSITION_COMPLETE = 60006,
+        SF_UNLOCK_CLIENTS       = 60007,
+        SF_SWAP_BUFFERS         = 60008,
+        SF_REPAINT_DONE         = 60009,
+
+        SF_FB_POST_BEFORE       = 60010,
+        SF_FB_POST_AFTER        = 60011,
+        SF_FB_DEQUEUE_BEFORE    = 60012,
+        SF_FB_DEQUEUE_AFTER     = 60013,
+        SF_FB_LOCK_BEFORE       = 60014,
+        SF_FB_LOCK_AFTER        = 60015,
+    };
+
+    inline void log(int32_t tag, int32_t buffer) {
+        if (CC_UNLIKELY(mEnabled))
+            logImpl(tag, buffer);
+    }
+    inline void log(int32_t tag, int32_t identity, int32_t buffer) {
+        if (CC_UNLIKELY(mEnabled))
+            logImpl(tag, identity, buffer);
+    }
+
+    GraphicLog();
+
+    void setEnabled(bool enable);
+};
+
+}
+
+#endif // _UI_GRAPHIC_LOG_H
+