1 // chrono -*- C++ -*-
2 
3 // Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 #include <chrono>
26 
27 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
28 
29 // conditional inclusion of sys/time.h for gettimeofday
30 #if !defined(_GLIBCXX_USE_CLOCK_MONOTONIC) && \
31     !defined(_GLIBCXX_USE_CLOCK_REALTIME) && \
32      defined(_GLIBCXX_USE_GETTIMEOFDAY)
33 #include <sys/time.h>
34 #endif
35 
36 namespace std _GLIBCXX_VISIBILITY(default)
37 {
38   namespace chrono
39   {
40   _GLIBCXX_BEGIN_NAMESPACE_VERSION
41 
42     constexpr bool system_clock::is_steady;
43 
44     system_clock::time_point
45     system_clock::now() noexcept
46     {
47 #ifdef _GLIBCXX_USE_CLOCK_REALTIME
48       timespec tp;
49       // -EINVAL, -EFAULT
50       clock_gettime(CLOCK_REALTIME, &tp);
51       return time_point(duration(chrono::seconds(tp.tv_sec)
52 				 + chrono::nanoseconds(tp.tv_nsec)));
53 #elif defined(_GLIBCXX_USE_GETTIMEOFDAY)
54       timeval tv;
55       // EINVAL, EFAULT
56       gettimeofday(&tv, 0);
57       return time_point(duration(chrono::seconds(tv.tv_sec)
58 				 + chrono::microseconds(tv.tv_usec)));
59 #else
60       std::time_t __sec = std::time(0);
61       return system_clock::from_time_t(__sec);
62 #endif
63     }
64 
65 #ifdef _GLIBCXX_USE_CLOCK_MONOTONIC
66     constexpr bool steady_clock::is_steady;
67 
68     steady_clock::time_point
69     steady_clock::now() noexcept
70     {
71       timespec tp;
72       // -EINVAL, -EFAULT
73       clock_gettime(CLOCK_MONOTONIC, &tp);
74       return time_point(duration(chrono::seconds(tp.tv_sec)
75 				 + chrono::nanoseconds(tp.tv_nsec)));
76     }
77 #endif
78 
79   _GLIBCXX_END_NAMESPACE_VERSION
80   } // namespace chrono
81 } // namespace std
82 
83 #endif // _GLIBCXX_USE_C99_STDINT_TR1
84