text: //===-- Timer.cpp -----------------------------------------------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  #include "Timer.h"
  #include <assert.h>
  
  using namespace lldb_perf;
  
  TimeGauge::TimeType TimeGauge::Now() { return high_resolution_clock::now(); }
  
  TimeGauge::TimeGauge() : m_start(), m_state(TimeGauge::State::eNeverUsed) {}
  
  void TimeGauge::Start() {
    m_state = TimeGauge::State::eCounting;
    m_start = Now();
  }
  
  double TimeGauge::Stop() {
    m_stop = Now();
    assert(m_state == TimeGauge::State::eCounting &&
           "cannot stop a non-started clock");
    m_state = TimeGauge::State::eStopped;
    m_delta = duration_cast<duration<double>>(m_stop - m_start).count();
    return m_delta;
  }
  
  double TimeGauge::GetStartValue() const {
    return (double)m_start.time_since_epoch().count() *
           (double)system_clock::period::num / (double)system_clock::period::den;
  }
  
  double TimeGauge::GetStopValue() const {
    return (double)m_stop.time_since_epoch().count() *
           (double)system_clock::period::num / (double)system_clock::period::den;
  }
  
  double TimeGauge::GetDeltaValue() const {
    assert(m_state == TimeGauge::State::eStopped &&
           "clock must be used before you can evaluate it");
    return m_delta;
  }
  