xref: /llvm-project/libcxx/src/filesystem/filesystem_clock.cpp (revision 5f1ba3a5020acdac4a7368f19b074577b5a6da8c)
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 #include "time_utils.h"
15 
16 #if defined(_LIBCPP_WIN32API)
17 # define WIN32_LEAN_AND_MEAN
18 # define NOMINMAX
19 # include <windows.h>
20 #endif
21 
22 #if __has_include(<unistd.h>)
23 # include <unistd.h> // _POSIX_TIMERS
24 #endif
25 
26 #if __has_include(<sys/time.h>)
27 # include <sys/time.h> // for gettimeofday and timeval
28 #endif
29 
30 #if !defined(__APPLE__) && defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0
31 # define _LIBCPP_USE_CLOCK_GETTIME
32 #endif
33 
34 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
35 
36 const bool _FilesystemClock::is_steady;
37 
38 _FilesystemClock::time_point _FilesystemClock::now() noexcept {
39   typedef chrono::duration<rep> __secs;
40 #if defined(_LIBCPP_WIN32API)
41   typedef chrono::duration<rep, nano> __nsecs;
42   FILETIME time;
43   GetSystemTimeAsFileTime(&time);
44   detail::TimeSpec tp = detail::filetime_to_timespec(time);
45   return time_point(__secs(tp.tv_sec) +
46                     chrono::duration_cast<duration>(__nsecs(tp.tv_nsec)));
47 #elif defined(_LIBCPP_USE_CLOCK_GETTIME) && defined(CLOCK_REALTIME)
48   typedef chrono::duration<rep, nano> __nsecs;
49   struct timespec tp;
50   if (0 != clock_gettime(CLOCK_REALTIME, &tp))
51     __throw_system_error(errno, "clock_gettime(CLOCK_REALTIME) failed");
52   return time_point(__secs(tp.tv_sec) +
53                     chrono::duration_cast<duration>(__nsecs(tp.tv_nsec)));
54 #else
55   typedef chrono::duration<rep, micro> __microsecs;
56   timeval tv;
57   gettimeofday(&tv, 0);
58   return time_point(__secs(tv.tv_sec) + __microsecs(tv.tv_usec));
59 #endif // CLOCK_REALTIME
60 }
61 
62 _LIBCPP_END_NAMESPACE_FILESYSTEM
63