1 files changed, 46 insertions, 0 deletions
diff --git a/libs/hwui/renderthread/TimeLord.cpp b/libs/hwui/renderthread/TimeLord.cpp
new file mode 100644
index 000000000000..758d96e96043
--- /dev/null
+++ b/libs/hwui/renderthread/TimeLord.cpp
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+#include "TimeLord.h"
+
+namespace android {
+namespace uirenderer {
+namespace renderthread {
+
+TimeLord::TimeLord()
+        : mFrameIntervalNanos(0)
+        , mFrameTimeNanos(0) {
+}
+
+void TimeLord::vsyncReceived(nsecs_t vsync) {
+    if (vsync > mFrameTimeNanos) {
+        mFrameTimeNanos = vsync;
+    }
+}
+
+nsecs_t TimeLord::frameTimeMs() {
+    // Logic copied from Choreographer.java
+    nsecs_t now = systemTime(CLOCK_MONOTONIC);
+    nsecs_t jitterNanos = now - mFrameTimeNanos;
+    if (jitterNanos >= mFrameIntervalNanos) {
+        nsecs_t lastFrameOffset = jitterNanos % mFrameIntervalNanos;
+        mFrameTimeNanos = now - lastFrameOffset;
+    }
+    return nanoseconds_to_milliseconds(mFrameTimeNanos);
+}
+
+} /* namespace renderthread */
+} /* namespace uirenderer */
+} /* namespace android */