starboard/shared/win32/time_utils.h

// Copyright 2017 The Cobalt 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.

#ifndef STARBOARD_SHARED_WIN32_TIME_UTILS_H_
#define STARBOARD_SHARED_WIN32_TIME_UTILS_H_

#include "starboard/common/log.h"

namespace starboard {
namespace shared {
namespace win32 {

inline int64_t ConvertFileTimeTicksToUsec(const LARGE_INTEGER ticks) {
  // According to
  // https://msdn.microsoft.com/en-us/library/windows/desktop/ms724284(v=vs.85).aspx
  // FILETIME format is "Contains a 64-bit value representing the number of
  // 100-nanosecond intervals since January 1, 1601 (UTC)"
  const uint64_t kNumber100nanosecondTicksInMicrosecond = 10;
  return ticks.QuadPart / kNumber100nanosecondTicksInMicrosecond;
}

inline int64_t ConvertFileTimeToUsec(const FILETIME file_time) {
  // According to
  // https://msdn.microsoft.com/en-us/library/windows/desktop/ms724284(v=vs.85).aspx
  // FILETIME format is "Contains a 64-bit value representing the number of
  // 100-nanosecond intervals since January 1, 1601 (UTC)"
  LARGE_INTEGER ticks;
  ticks.QuadPart = (static_cast<LONGLONG>(file_time.dwHighDateTime) << 32) |
                   file_time.dwLowDateTime;
  return ConvertFileTimeTicksToUsec(ticks);
}

// Many Win32 calls take millis, but Starboard uses microseconds.
// Many nplb tests assume waits are at least as long as requested, so
// round up.
inline DWORD ConvertUsecToMillisRoundUp(int64_t duration_usec) {
  const int64_t milliseconds_to_sleep = (duration_usec + 1000 - 1) / 1000;
  return static_cast<DWORD>(milliseconds_to_sleep);
}

}  // namespace win32
}  // namespace shared
}  // namespace starboard

#endif  // STARBOARD_SHARED_WIN32_TIME_UTILS_H_