Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 1 | //===------------------------- chrono.cpp ---------------------------------===// |
| 2 | // |
Howard Hinnant | f5256e1 | 2010-05-11 21:36:01 +0000 | [diff] [blame] | 3 | // The LLVM Compiler Infrastructure |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 4 | // |
Howard Hinnant | b64f8b0 | 2010-11-16 22:09:02 +0000 | [diff] [blame] | 5 | // This file is dual licensed under the MIT and the University of Illinois Open |
| 6 | // Source Licenses. See LICENSE.TXT for details. |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | |
| 10 | #include "chrono" |
Marshall Clow | 8c42c8c | 2015-06-23 14:45:02 +0000 | [diff] [blame] | 11 | #include "cerrno" // errno |
| 12 | #include "system_error" // __throw_system_error |
| 13 | #include <time.h> // clock_gettime, CLOCK_MONOTONIC and CLOCK_REALTIME |
Ed Schouten | 22a6d5a | 2015-05-14 20:54:18 +0000 | [diff] [blame] | 14 | |
| 15 | #if !defined(CLOCK_REALTIME) |
| 16 | #include <sys/time.h> // for gettimeofday and timeval |
| 17 | #endif |
| 18 | |
| 19 | #if !defined(_LIBCPP_HAS_NO_MONOTONIC_CLOCK) && !defined(CLOCK_MONOTONIC) |
| 20 | #if __APPLE__ |
| 21 | #include <mach/mach_time.h> // mach_absolute_time, mach_timebase_info_data_t |
| 22 | #else |
| 23 | #error "Monotonic clock not implemented" |
| 24 | #endif |
| 25 | #endif |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 26 | |
| 27 | _LIBCPP_BEGIN_NAMESPACE_STD |
| 28 | |
| 29 | namespace chrono |
| 30 | { |
| 31 | |
| 32 | // system_clock |
| 33 | |
Howard Hinnant | 0a69fa1 | 2012-12-12 21:14:28 +0000 | [diff] [blame] | 34 | const bool system_clock::is_steady; |
| 35 | |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 36 | system_clock::time_point |
Howard Hinnant | 756a176 | 2011-05-28 18:34:36 +0000 | [diff] [blame] | 37 | system_clock::now() _NOEXCEPT |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 38 | { |
Ed Schouten | 22a6d5a | 2015-05-14 20:54:18 +0000 | [diff] [blame] | 39 | #ifdef CLOCK_REALTIME |
| 40 | struct timespec tp; |
| 41 | if (0 != clock_gettime(CLOCK_REALTIME, &tp)) |
| 42 | __throw_system_error(errno, "clock_gettime(CLOCK_REALTIME) failed"); |
| 43 | return time_point(seconds(tp.tv_sec) + microseconds(tp.tv_nsec / 1000)); |
| 44 | #else // !CLOCK_REALTIME |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 45 | timeval tv; |
| 46 | gettimeofday(&tv, 0); |
| 47 | return time_point(seconds(tv.tv_sec) + microseconds(tv.tv_usec)); |
Ed Schouten | 22a6d5a | 2015-05-14 20:54:18 +0000 | [diff] [blame] | 48 | #endif // CLOCK_REALTIME |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 49 | } |
| 50 | |
| 51 | time_t |
Howard Hinnant | 756a176 | 2011-05-28 18:34:36 +0000 | [diff] [blame] | 52 | system_clock::to_time_t(const time_point& t) _NOEXCEPT |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 53 | { |
| 54 | return time_t(duration_cast<seconds>(t.time_since_epoch()).count()); |
| 55 | } |
| 56 | |
| 57 | system_clock::time_point |
Howard Hinnant | 756a176 | 2011-05-28 18:34:36 +0000 | [diff] [blame] | 58 | system_clock::from_time_t(time_t t) _NOEXCEPT |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 59 | { |
| 60 | return system_clock::time_point(seconds(t)); |
| 61 | } |
| 62 | |
Jonathan Roelofs | c578065 | 2014-09-02 21:14:38 +0000 | [diff] [blame] | 63 | #ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 64 | // steady_clock |
Ed Schouten | 22a6d5a | 2015-05-14 20:54:18 +0000 | [diff] [blame] | 65 | // |
| 66 | // Warning: If this is not truly steady, then it is non-conforming. It is |
| 67 | // better for it to not exist and have the rest of libc++ use system_clock |
| 68 | // instead. |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 69 | |
Howard Hinnant | 0a69fa1 | 2012-12-12 21:14:28 +0000 | [diff] [blame] | 70 | const bool steady_clock::is_steady; |
| 71 | |
Ed Schouten | 22a6d5a | 2015-05-14 20:54:18 +0000 | [diff] [blame] | 72 | #ifdef CLOCK_MONOTONIC |
| 73 | |
| 74 | steady_clock::time_point |
| 75 | steady_clock::now() _NOEXCEPT |
| 76 | { |
| 77 | struct timespec tp; |
| 78 | if (0 != clock_gettime(CLOCK_MONOTONIC, &tp)) |
| 79 | __throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC) failed"); |
| 80 | return time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec)); |
| 81 | } |
| 82 | |
| 83 | #elif defined(__APPLE__) |
| 84 | |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 85 | // mach_absolute_time() * MachInfo.numer / MachInfo.denom is the number of |
| 86 | // nanoseconds since the computer booted up. MachInfo.numer and MachInfo.denom |
| 87 | // are run time constants supplied by the OS. This clock has no relationship |
| 88 | // to the Gregorian calendar. It's main use is as a high resolution timer. |
| 89 | |
| 90 | // MachInfo.numer / MachInfo.denom is often 1 on the latest equipment. Specialize |
| 91 | // for that case as an optimization. |
| 92 | |
| 93 | #pragma GCC visibility push(hidden) |
| 94 | |
| 95 | static |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 96 | steady_clock::rep |
| 97 | steady_simplified() |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 98 | { |
Howard Hinnant | ec3773c | 2011-12-01 20:21:04 +0000 | [diff] [blame] | 99 | return static_cast<steady_clock::rep>(mach_absolute_time()); |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 100 | } |
| 101 | |
| 102 | static |
| 103 | double |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 104 | compute_steady_factor() |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 105 | { |
| 106 | mach_timebase_info_data_t MachInfo; |
| 107 | mach_timebase_info(&MachInfo); |
| 108 | return static_cast<double>(MachInfo.numer) / MachInfo.denom; |
| 109 | } |
| 110 | |
| 111 | static |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 112 | steady_clock::rep |
| 113 | steady_full() |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 114 | { |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 115 | static const double factor = compute_steady_factor(); |
| 116 | return static_cast<steady_clock::rep>(mach_absolute_time() * factor); |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 117 | } |
| 118 | |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 119 | typedef steady_clock::rep (*FP)(); |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 120 | |
| 121 | static |
| 122 | FP |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 123 | init_steady_clock() |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 124 | { |
| 125 | mach_timebase_info_data_t MachInfo; |
| 126 | mach_timebase_info(&MachInfo); |
| 127 | if (MachInfo.numer == MachInfo.denom) |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 128 | return &steady_simplified; |
| 129 | return &steady_full; |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 130 | } |
| 131 | |
Daniel Dunbar | 04acaca | 2010-09-04 03:15:51 +0000 | [diff] [blame] | 132 | #pragma GCC visibility pop |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 133 | |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 134 | steady_clock::time_point |
Howard Hinnant | 756a176 | 2011-05-28 18:34:36 +0000 | [diff] [blame] | 135 | steady_clock::now() _NOEXCEPT |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 136 | { |
Howard Hinnant | f8f8521 | 2010-11-20 19:16:30 +0000 | [diff] [blame] | 137 | static FP fp = init_steady_clock(); |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 138 | return time_point(duration(fp())); |
| 139 | } |
| 140 | |
Ed Schouten | 22a6d5a | 2015-05-14 20:54:18 +0000 | [diff] [blame] | 141 | #else |
| 142 | #error "Monotonic clock not implemented" |
| 143 | #endif |
Howard Hinnant | adff489 | 2010-05-24 17:49:41 +0000 | [diff] [blame] | 144 | |
Jonathan Roelofs | c578065 | 2014-09-02 21:14:38 +0000 | [diff] [blame] | 145 | #endif // !_LIBCPP_HAS_NO_MONOTONIC_CLOCK |
| 146 | |
Howard Hinnant | bc8d3f9 | 2010-05-11 19:42:16 +0000 | [diff] [blame] | 147 | } |
| 148 | |
| 149 | _LIBCPP_END_NAMESPACE_STD |