libcxx/src/filesystem/filesystem_clock.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include <__config>
  10 #include <chrono>
  11 #include <filesystem>
  12 #include <time.h>
  13
  14 #if defined(_LIBCPP_WIN32API)
  15 #  include "time_utils.h"
  16 #endif
  17
  18 #if defined(_LIBCPP_WIN32API)
  19 # define WIN32_LEAN_AND_MEAN
  20 # define NOMINMAX
  21 # include <windows.h>
  22 #endif
  23
  24 #if __has_include(<unistd.h>)
  25 # include <unistd.h> // _POSIX_TIMERS
  26 #endif
  27
  28 #if __has_include(<sys/time.h>)
  29 # include <sys/time.h> // for gettimeofday and timeval
  30 #endif
  31
  32 #if defined(__APPLE__) || defined (__gnu_hurd__) || (defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0)
  33 # define _LIBCPP_HAS_CLOCK_GETTIME
  34 #endif
  35
  36 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
  37
  38 const bool _FilesystemClock::is_steady;
  39
  40 _FilesystemClock::time_point _FilesystemClock::now() noexcept {
  41   typedef chrono::duration<rep> __secs;
  42 #if defined(_LIBCPP_WIN32API)
  43   typedef chrono::duration<rep, nano> __nsecs;
  44   FILETIME time;
  45   GetSystemTimeAsFileTime(&time);
  46   detail::TimeSpec tp = detail::filetime_to_timespec(time);
  47   return time_point(__secs(tp.tv_sec) +
  48                     chrono::duration_cast<duration>(__nsecs(tp.tv_nsec)));
  49 #elif defined(_LIBCPP_HAS_CLOCK_GETTIME)
  50   typedef chrono::duration<rep, nano> __nsecs;
  51   struct timespec tp;
  52   if (0 != clock_gettime(CLOCK_REALTIME, &tp))
  53     __throw_system_error(errno, "clock_gettime(CLOCK_REALTIME) failed");
  54   return time_point(__secs(tp.tv_sec) +
  55                     chrono::duration_cast<duration>(__nsecs(tp.tv_nsec)));
  56 #else
  57   typedef chrono::duration<rep, micro> __microsecs;
  58   timeval tv;
  59   gettimeofday(&tv, 0);
  60   return time_point(__secs(tv.tv_sec) + __microsecs(tv.tv_usec));
  61 #endif
  62 }
  63
  64 _LIBCPP_END_NAMESPACE_FILESYSTEM