1 // chrono -*- C++ -*- 2 3 // Copyright (C) 2008-2016 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 #include <chrono> 27 28 #ifdef _GLIBCXX_USE_C99_STDINT_TR1 29 30 // Conditional inclusion of sys/time.h for gettimeofday 31 #if !defined(_GLIBCXX_USE_CLOCK_MONOTONIC) && \ 32 !defined(_GLIBCXX_USE_CLOCK_REALTIME) && \ 33 defined(_GLIBCXX_USE_GETTIMEOFDAY) 34 #include <sys/time.h> 35 #endif 36 37 #ifdef _GLIBCXX_USE_CLOCK_GETTIME_SYSCALL 38 #include <unistd.h> 39 #include <sys/syscall.h> 40 #endif 41 42 namespace std _GLIBCXX_VISIBILITY(default) 43 { 44 namespace chrono 45 { 46 _GLIBCXX_BEGIN_NAMESPACE_VERSION 47 48 // XXX GLIBCXX_ABI Deprecated 49 inline namespace _V2 { 50 51 constexpr bool system_clock::is_steady; 52 53 system_clock::time_point now()54 system_clock::now() noexcept 55 { 56 #ifdef _GLIBCXX_USE_CLOCK_REALTIME 57 timespec tp; 58 // -EINVAL, -EFAULT 59 #ifdef _GLIBCXX_USE_CLOCK_GETTIME_SYSCALL 60 syscall(SYS_clock_gettime, CLOCK_REALTIME, &tp); 61 #else 62 clock_gettime(CLOCK_REALTIME, &tp); 63 #endif 64 return time_point(duration(chrono::seconds(tp.tv_sec) 65 + chrono::nanoseconds(tp.tv_nsec))); 66 #elif defined(_GLIBCXX_USE_GETTIMEOFDAY) 67 timeval tv; 68 // EINVAL, EFAULT 69 gettimeofday(&tv, 0); 70 return time_point(duration(chrono::seconds(tv.tv_sec) 71 + chrono::microseconds(tv.tv_usec))); 72 #else 73 std::time_t __sec = std::time(0); 74 return system_clock::from_time_t(__sec); 75 #endif 76 } 77 78 79 constexpr bool steady_clock::is_steady; 80 81 steady_clock::time_point now()82 steady_clock::now() noexcept 83 { 84 #ifdef _GLIBCXX_USE_CLOCK_MONOTONIC 85 timespec tp; 86 // -EINVAL, -EFAULT 87 #ifdef _GLIBCXX_USE_CLOCK_GETTIME_SYSCALL 88 syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &tp); 89 #else 90 clock_gettime(CLOCK_MONOTONIC, &tp); 91 #endif 92 return time_point(duration(chrono::seconds(tp.tv_sec) 93 + chrono::nanoseconds(tp.tv_nsec))); 94 #else 95 return time_point(system_clock::now().time_since_epoch()); 96 #endif 97 } 98 99 } // end inline namespace _V2 100 101 _GLIBCXX_END_NAMESPACE_VERSION 102 } // namespace chrono 103 } // namespace std 104 105 #endif // _GLIBCXX_USE_C99_STDINT_TR1 106