text: // Copyright 2014 The Crashpad Authors. All rights reserved.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #include "util/misc/clock.h"
  
  #include <windows.h>
  #include <sys/types.h>
  
  namespace {
  
  LARGE_INTEGER QpcFrequencyInternal() {
    LARGE_INTEGER frequency;
    QueryPerformanceFrequency(&frequency);
    return frequency;
  }
  
  int64_t QpcFrequency() {
    static LARGE_INTEGER frequency = QpcFrequencyInternal();
    return frequency.QuadPart;
  }
  
  }  // namespace
  
  namespace crashpad {
  
  uint64_t ClockMonotonicNanoseconds() {
    LARGE_INTEGER time;
    QueryPerformanceCounter(&time);
    int64_t frequency = QpcFrequency();
    int64_t whole_seconds = time.QuadPart / frequency;
    int64_t leftover_ticks = time.QuadPart % frequency;
    const int64_t kNanosecondsPerSecond = static_cast<const int64_t>(1E9);
    return (whole_seconds * kNanosecondsPerSecond) +
           ((leftover_ticks * kNanosecondsPerSecond) / frequency);
  }
  
  }  // namespace crashpad
  