cc/debug/lap_timer.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "cc/debug/lap_timer.h"
   6
   7 #include "base/logging.h"
   8
   9 namespace cc {
  10
  11 namespace {
  12
  13 base::TimeTicks Now() {
  14   return base::TimeTicks::IsThreadNowSupported() ? base::TimeTicks::ThreadNow()
  15                                                  : base::TimeTicks::Now();
  16 }
  17
  18 // Default values.
  19 static const int kTimeLimitMillis = 3000;
  20 static const int kWarmupRuns = 5;
  21 static const int kTimeCheckInterval = 10;
  22
  23 }  // namespace
  24
  25 LapTimer::LapTimer(int warmup_laps,
  26                    base::TimeDelta time_limit,
  27                    int check_interval)
  28     : warmup_laps_(warmup_laps),
  29       remaining_warmups_(0),
  30       remaining_no_check_laps_(0),
  31       time_limit_(time_limit),
  32       check_interval_(check_interval) {
  33   DCHECK_GT(check_interval, 0);
  34   Reset();
  35 }
  36
  37 LapTimer::LapTimer()
  38     : LapTimer(kWarmupRuns,
  39                base::TimeDelta::FromMilliseconds(kTimeLimitMillis),
  40                kTimeCheckInterval) {
  41 }
  42
  43 void LapTimer::Reset() {
  44   accumulator_ = base::TimeDelta();
  45   num_laps_ = 0;
  46   remaining_warmups_ = warmup_laps_;
  47   remaining_no_check_laps_ = check_interval_;
  48   Start();
  49 }
  50
  51 void LapTimer::Start() {
  52   start_time_ = Now();
  53 }
  54
  55 bool LapTimer::IsWarmedUp() { return remaining_warmups_ <= 0; }
  56
  57 void LapTimer::NextLap() {
  58   if (!IsWarmedUp()) {
  59     --remaining_warmups_;
  60     if (IsWarmedUp()) {
  61       Start();
  62     }
  63     return;
  64   }
  65   ++num_laps_;
  66   --remaining_no_check_laps_;
  67   if (!remaining_no_check_laps_) {
  68     base::TimeTicks now = Now();
  69     accumulator_ += now - start_time_;
  70     start_time_ = now;
  71     remaining_no_check_laps_ = check_interval_;
  72   }
  73 }
  74
  75 bool LapTimer::HasTimeLimitExpired() { return accumulator_ >= time_limit_; }
  76
  77 bool LapTimer::HasTimedAllLaps() { return !(num_laps_ % check_interval_); }
  78
  79 float LapTimer::MsPerLap() {
  80   DCHECK(HasTimedAllLaps());
  81   return accumulator_.InMillisecondsF() / num_laps_;
  82 }
  83
  84 float LapTimer::LapsPerSecond() {
  85   DCHECK(HasTimedAllLaps());
  86   return num_laps_ / accumulator_.InSecondsF();
  87 }
  88
  89 int LapTimer::NumLaps() { return num_laps_; }
  90
  91 }  // namespace cc