Home | History | Annotate | Download | only in VisualBench 
      1 /*
      2  * Copyright 2015 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "TimingStateMachine.h"
      9 
     10 #include "SkCanvas.h"
     11 #include "SkCommandLineFlags.h"
     12 
     13 DEFINE_int32(gpuFrameLag, 5, "Overestimate of maximum number of frames GPU is allowed to lag.");
     14 DEFINE_int32(frames, 5, "Number of frames of each skp to render per sample.");
     15 DEFINE_double(loopMs, 5, "Each benchmark will be tuned until it takes loopsMs millseconds.");
     16 
     17 static double now_ms() { return SkTime::GetNSecs() * 1e-6; }
     18 
     19 TimingStateMachine::TimingStateMachine()
     20     : fCurrentFrame(0)
     21     , fLoops(1)
     22     , fLastMeasurement(0.)
     23     , fState(kPreWarm_State)
     24     , fInnerState(kTuning_InnerState) {
     25 }
     26 
     27 TimingStateMachine::ParentEvents TimingStateMachine::nextFrame(bool preWarmBetweenSamples) {
     28     ParentEvents parentEvent = kTiming_ParentEvents;
     29     switch (fState) {
     30         case kPreWarm_State: {
     31             if (fCurrentFrame >= FLAGS_gpuFrameLag) {
     32                 fCurrentFrame = 0;
     33                 fStartTime = now_ms();
     34                 fState = kTiming_State;
     35             } else {
     36                 fCurrentFrame++;
     37             }
     38             break;
     39         }
     40         case kTiming_State: {
     41             switch (fInnerState) {
     42                 case kTuning_InnerState: {
     43                     if (1 << 30 == fLoops) {
     44                         // We're about to wrap.  Something's wrong with the bench.
     45                         SkDebugf("InnerLoops wrapped\n");
     46                         fLoops = 1;
     47                     } else {
     48                         double elapsedMs = now_ms() - fStartTime;
     49                         if (elapsedMs < FLAGS_loopMs) {
     50                             fLoops *= 2;
     51                         } else {
     52                             fInnerState = kTiming_InnerState;
     53                         }
     54                         fState = kPreWarm_State;
     55                         fCurrentFrame = 0;
     56                         parentEvent = kReset_ParentEvents;
     57                     }
     58                     break;
     59                 }
     60                 case kTiming_InnerState: {
     61                     if (fCurrentFrame >= FLAGS_frames) {
     62                         double now = now_ms();
     63                         fLastMeasurement = (now - fStartTime) / (FLAGS_frames * fLoops);
     64                         fCurrentFrame = 0;
     65                         parentEvent = kTimingFinished_ParentEvents;
     66                         if (preWarmBetweenSamples) {
     67                             fState = kPreWarm_State;
     68                         } else {
     69                             fStartTime = now;
     70                         }
     71                     } else {
     72                         fCurrentFrame++;
     73                     }
     74                     break;
     75                 }
     76             }
     77         }
     78         break;
     79     }
     80     return parentEvent;
     81 }
     82 
     83 void TimingStateMachine::nextBenchmark() {
     84     fLoops = 1;
     85     fInnerState = kTuning_InnerState;
     86     fState = kPreWarm_State;
     87 }
     88