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
now_ms()17 static double now_ms() { return SkTime::GetNSecs() * 1e-6; }
18
TimingStateMachine()19 TimingStateMachine::TimingStateMachine()
20 : fCurrentFrame(0)
21 , fLoops(1)
22 , fLastMeasurement(0.)
23 , fState(kPreWarm_State)
24 , fInnerState(kTuning_InnerState) {
25 }
26
nextFrame(bool preWarmBetweenSamples)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
nextBenchmark()83 void TimingStateMachine::nextBenchmark() {
84 fLoops = 1;
85 fInnerState = kTuning_InnerState;
86 fState = kPreWarm_State;
87 }
88