TimeLord.cpp revision 18f16e6fba74eda173e1e7c869e6e2e2acc073ff
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 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 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 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. 15 */ 16#include "TimeLord.h" 17 18namespace android { 19namespace uirenderer { 20namespace renderthread { 21 22TimeLord::TimeLord() 23 : mFrameIntervalNanos(0) 24 , mFrameTimeNanos(0) { 25} 26 27void TimeLord::vsyncReceived(nsecs_t vsync) { 28 if (vsync > mFrameTimeNanos) { 29 mFrameTimeNanos = vsync; 30 } 31} 32 33nsecs_t TimeLord::frameTimeMs() { 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; 40 } 41 return nanoseconds_to_milliseconds(mFrameTimeNanos); 42} 43 44} /* namespace renderthread */ 45} /* namespace uirenderer */ 46} /* namespace android */ 47