auto import from //depot/cupcake/@135843
diff --git a/include/private/ui/SurfaceFlingerSynchro.h b/include/private/ui/SurfaceFlingerSynchro.h
new file mode 100644
index 0000000..ff91b61
--- /dev/null
+++ b/include/private/ui/SurfaceFlingerSynchro.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2008 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 ANDROID_SURFACE_FLINGER_SYNCHRO_H
+#define ANDROID_SURFACE_FLINGER_SYNCHRO_H
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <utils/Errors.h>
+#include <utils/threads.h>
+#include <ui/ISurfaceComposer.h>
+
+namespace android {
+
+class SurfaceFlinger;
+
+class SurfaceFlingerSynchro
+{
+public:
+
+ // client constructor
+ SurfaceFlingerSynchro(const sp<ISurfaceComposer>& flinger);
+ ~SurfaceFlingerSynchro();
+
+ // signal surfaceflinger for some work
+ status_t signal();
+
+private:
+ class Barrier {
+ public:
+ Barrier();
+ ~Barrier();
+ void open();
+ void close();
+ void waitAndClose();
+ status_t waitAndClose(nsecs_t timeout);
+ private:
+ enum { OPENED, CLOSED };
+ mutable Mutex lock;
+ mutable Condition cv;
+ volatile int state;
+ };
+
+ friend class SurfaceFlinger;
+
+ // server constructor
+ SurfaceFlingerSynchro();
+
+ void open();
+
+ // wait until there is some work to do
+ status_t wait();
+ status_t wait(nsecs_t timeout);
+
+ sp<ISurfaceComposer> mSurfaceComposer;
+ Barrier mBarrier;
+};
+
+}; // namespace android
+
+#endif // ANDROID_SURFACE_FLINGER_SYNCHRO_H
+