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 18 namespace android { 19 namespace uirenderer { 20 namespace renderthread { 21 22 TimeLord::TimeLord() 23 : mFrameIntervalNanos(milliseconds_to_nanoseconds(16)) 24 , mFrameTimeNanos(0) { 25 } 26 27 bool TimeLord::vsyncReceived(nsecs_t vsync) { 28 if (vsync > mFrameTimeNanos) { 29 mFrameTimeNanos = vsync; 30 return true; 31 } 32 return false; 33 } 34 35 nsecs_t TimeLord::computeFrameTimeMs() { 36 // Logic copied from Choreographer.java 37 nsecs_t now = systemTime(CLOCK_MONOTONIC); 38 nsecs_t jitterNanos = now - mFrameTimeNanos; 39 if (jitterNanos >= mFrameIntervalNanos) { 40 nsecs_t lastFrameOffset = jitterNanos % mFrameIntervalNanos; 41 mFrameTimeNanos = now - lastFrameOffset; 42 } 43 return nanoseconds_to_milliseconds(mFrameTimeNanos); 44 } 45 46 } /* namespace renderthread */ 47 } /* namespace uirenderer */ 48 } /* namespace android */ 49
