2 * Copyright (C) 2014 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
19 namespace uirenderer {
20 namespace renderthread {
23 : mFrameIntervalNanos(milliseconds_to_nanoseconds(16))
24 , mFrameTimeNanos(0) {
27 void TimeLord::vsyncReceived(nsecs_t vsync) {
28 if (vsync > mFrameTimeNanos) {
29 mFrameTimeNanos = vsync;
33 nsecs_t TimeLord::computeFrameTimeMs() {
34 // Logic copied from Choreographer.java
35 nsecs_t now = systemTime(CLOCK_MONOTONIC);
36 nsecs_t jitterNanos = now - mFrameTimeNanos;
37 if (jitterNanos >= mFrameIntervalNanos) {
38 nsecs_t lastFrameOffset = jitterNanos % mFrameIntervalNanos;
39 mFrameTimeNanos = now - lastFrameOffset;
41 return nanoseconds_to_milliseconds(mFrameTimeNanos);
44 } /* namespace renderthread */
45 } /* namespace uirenderer */
46 } /* namespace android */