1 // Compatibility symbols for previous versions, C++0x bits -*- C++ -*- 2 3 // Copyright (C) 2013-2018 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 <bits/c++config.h> 26 27 #ifdef _GLIBCXX_USE_C99_STDINT_TR1 28 29 #ifdef _GLIBCXX_USE_GETTIMEOFDAY 30 #include <sys/time.h> 31 #endif 32 33 #define system_clock system_clockXX 34 #define steady_clock steady_clockXX 35 #include <chrono> 36 #undef system_clock 37 #undef steady_clock 38 39 namespace std _GLIBCXX_VISIBILITY(default) 40 { 41 _GLIBCXX_BEGIN_NAMESPACE_VERSION 42 43 namespace chrono 44 { 45 // NB: Default configuration was no realtime. 46 struct system_clock 47 { 48 #ifdef _GLIBCXX_USE_GETTIMEOFDAY 49 typedef chrono::microseconds duration; 50 #else 51 typedef chrono::seconds duration; 52 #endif 53 54 typedef duration::rep rep; 55 typedef duration::period period; 56 typedef chrono::time_point<system_clock, duration> time_point; 57 58 static_assert(system_clock::duration::min() 59 < system_clock::duration::zero(), 60 "a clock's minimum duration cannot be less than its epoch"); 61 62 static constexpr bool is_steady = false; 63 64 static time_point 65 now() noexcept; 66 }; 67 68 constexpr bool system_clock::is_steady; 69 70 system_clock::time_point 71 system_clock::now() noexcept 72 { 73 #ifdef _GLIBCXX_USE_GETTIMEOFDAY 74 timeval tv; 75 // EINVAL, EFAULT 76 gettimeofday(&tv, 0); 77 return time_point(duration(chrono::seconds(tv.tv_sec) 78 + chrono::microseconds(tv.tv_usec))); 79 #else 80 std::time_t __sec = std::time(0); 81 // This is the conversion done by system_clock::from_time_t(__sec) 82 typedef chrono::time_point<system_clock, seconds> __from; 83 return time_point_cast<system_clock::duration> 84 (__from(chrono::seconds(__sec))); 85 #endif 86 } 87 } // namespace chrono 88 89 _GLIBCXX_END_NAMESPACE_VERSION 90 } // namespace std 91 92 #endif // _GLIBCXX_USE_C99_STDINT_TR1 93