xref: /netbsd-src/external/apache2/llvm/dist/libcxx/src/chrono.cpp (revision 4d6fc14bc9b0c5bf3e30be318c143ee82cadd108)
1*4d6fc14bSjoerg //===------------------------- chrono.cpp ---------------------------------===//
2*4d6fc14bSjoerg //
3*4d6fc14bSjoerg // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*4d6fc14bSjoerg // See https://llvm.org/LICENSE.txt for license information.
5*4d6fc14bSjoerg // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*4d6fc14bSjoerg //
7*4d6fc14bSjoerg //===----------------------------------------------------------------------===//
8*4d6fc14bSjoerg 
9*4d6fc14bSjoerg #if defined(__MVS__)
10*4d6fc14bSjoerg // As part of monotonic clock support on z/OS we need macro _LARGE_TIME_API
11*4d6fc14bSjoerg // to be defined before any system header to include definition of struct timespec64.
12*4d6fc14bSjoerg #define _LARGE_TIME_API
13*4d6fc14bSjoerg #endif
14*4d6fc14bSjoerg 
15*4d6fc14bSjoerg #include "chrono"
16*4d6fc14bSjoerg #include "cerrno"        // errno
17*4d6fc14bSjoerg #include "system_error"  // __throw_system_error
18*4d6fc14bSjoerg 
19*4d6fc14bSjoerg #if defined(__MVS__)
20*4d6fc14bSjoerg #include <__support/ibm/gettod_zos.h> // gettimeofdayMonotonic
21*4d6fc14bSjoerg #endif
22*4d6fc14bSjoerg 
23*4d6fc14bSjoerg #include <time.h>        // clock_gettime and CLOCK_{MONOTONIC,REALTIME,MONOTONIC_RAW}
24*4d6fc14bSjoerg #include "include/apple_availability.h"
25*4d6fc14bSjoerg 
26*4d6fc14bSjoerg #if __has_include(<unistd.h>)
27*4d6fc14bSjoerg # include <unistd.h>
28*4d6fc14bSjoerg #endif
29*4d6fc14bSjoerg 
30*4d6fc14bSjoerg #if __has_include(<sys/time.h>)
31*4d6fc14bSjoerg # include <sys/time.h> // for gettimeofday and timeval
32*4d6fc14bSjoerg #endif
33*4d6fc14bSjoerg 
34*4d6fc14bSjoerg #if !defined(__APPLE__) && _POSIX_TIMERS > 0
35*4d6fc14bSjoerg # define _LIBCPP_USE_CLOCK_GETTIME
36*4d6fc14bSjoerg #endif
37*4d6fc14bSjoerg 
38*4d6fc14bSjoerg #if defined(_LIBCPP_WIN32API)
39*4d6fc14bSjoerg #  define WIN32_LEAN_AND_MEAN
40*4d6fc14bSjoerg #  define VC_EXTRA_LEAN
41*4d6fc14bSjoerg #  include <windows.h>
42*4d6fc14bSjoerg #  if _WIN32_WINNT >= _WIN32_WINNT_WIN8
43*4d6fc14bSjoerg #    include <winapifamily.h>
44*4d6fc14bSjoerg #  endif
45*4d6fc14bSjoerg #endif // defined(_LIBCPP_WIN32API)
46*4d6fc14bSjoerg 
47*4d6fc14bSjoerg #if __has_include(<mach/mach_time.h>)
48*4d6fc14bSjoerg # include <mach/mach_time.h>
49*4d6fc14bSjoerg #endif
50*4d6fc14bSjoerg 
51*4d6fc14bSjoerg #if defined(__ELF__) && defined(_LIBCPP_LINK_RT_LIB)
52*4d6fc14bSjoerg #  pragma comment(lib, "rt")
53*4d6fc14bSjoerg #endif
54*4d6fc14bSjoerg 
55*4d6fc14bSjoerg _LIBCPP_BEGIN_NAMESPACE_STD
56*4d6fc14bSjoerg 
57*4d6fc14bSjoerg namespace chrono
58*4d6fc14bSjoerg {
59*4d6fc14bSjoerg 
60*4d6fc14bSjoerg //
61*4d6fc14bSjoerg // system_clock
62*4d6fc14bSjoerg //
63*4d6fc14bSjoerg 
64*4d6fc14bSjoerg #if defined(_LIBCPP_WIN32API)
65*4d6fc14bSjoerg 
__libcpp_system_clock_now()66*4d6fc14bSjoerg static system_clock::time_point __libcpp_system_clock_now() {
67*4d6fc14bSjoerg   // FILETIME is in 100ns units
68*4d6fc14bSjoerg   using filetime_duration =
69*4d6fc14bSjoerg       _VSTD::chrono::duration<__int64,
70*4d6fc14bSjoerg                               _VSTD::ratio_multiply<_VSTD::ratio<100, 1>,
71*4d6fc14bSjoerg                                                     nanoseconds::period>>;
72*4d6fc14bSjoerg 
73*4d6fc14bSjoerg   // The Windows epoch is Jan 1 1601, the Unix epoch Jan 1 1970.
74*4d6fc14bSjoerg   static _LIBCPP_CONSTEXPR const seconds nt_to_unix_epoch{11644473600};
75*4d6fc14bSjoerg 
76*4d6fc14bSjoerg   FILETIME ft;
77*4d6fc14bSjoerg #if _WIN32_WINNT >= _WIN32_WINNT_WIN8 && WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
78*4d6fc14bSjoerg   GetSystemTimePreciseAsFileTime(&ft);
79*4d6fc14bSjoerg #else
80*4d6fc14bSjoerg   GetSystemTimeAsFileTime(&ft);
81*4d6fc14bSjoerg #endif
82*4d6fc14bSjoerg 
83*4d6fc14bSjoerg   filetime_duration d{(static_cast<__int64>(ft.dwHighDateTime) << 32) |
84*4d6fc14bSjoerg                        static_cast<__int64>(ft.dwLowDateTime)};
85*4d6fc14bSjoerg   return system_clock::time_point(duration_cast<system_clock::duration>(d - nt_to_unix_epoch));
86*4d6fc14bSjoerg }
87*4d6fc14bSjoerg 
88*4d6fc14bSjoerg #elif defined(CLOCK_REALTIME) && defined(_LIBCPP_USE_CLOCK_GETTIME)
89*4d6fc14bSjoerg 
90*4d6fc14bSjoerg static system_clock::time_point __libcpp_system_clock_now() {
91*4d6fc14bSjoerg   struct timespec tp;
92*4d6fc14bSjoerg   if (0 != clock_gettime(CLOCK_REALTIME, &tp))
93*4d6fc14bSjoerg     __throw_system_error(errno, "clock_gettime(CLOCK_REALTIME) failed");
94*4d6fc14bSjoerg   return system_clock::time_point(seconds(tp.tv_sec) + microseconds(tp.tv_nsec / 1000));
95*4d6fc14bSjoerg }
96*4d6fc14bSjoerg 
97*4d6fc14bSjoerg #else
98*4d6fc14bSjoerg 
99*4d6fc14bSjoerg static system_clock::time_point __libcpp_system_clock_now() {
100*4d6fc14bSjoerg     timeval tv;
101*4d6fc14bSjoerg     gettimeofday(&tv, 0);
102*4d6fc14bSjoerg     return system_clock::time_point(seconds(tv.tv_sec) + microseconds(tv.tv_usec));
103*4d6fc14bSjoerg }
104*4d6fc14bSjoerg 
105*4d6fc14bSjoerg #endif
106*4d6fc14bSjoerg 
107*4d6fc14bSjoerg const bool system_clock::is_steady;
108*4d6fc14bSjoerg 
109*4d6fc14bSjoerg system_clock::time_point
now()110*4d6fc14bSjoerg system_clock::now() noexcept
111*4d6fc14bSjoerg {
112*4d6fc14bSjoerg     return __libcpp_system_clock_now();
113*4d6fc14bSjoerg }
114*4d6fc14bSjoerg 
115*4d6fc14bSjoerg time_t
to_time_t(const time_point & t)116*4d6fc14bSjoerg system_clock::to_time_t(const time_point& t) noexcept
117*4d6fc14bSjoerg {
118*4d6fc14bSjoerg     return time_t(duration_cast<seconds>(t.time_since_epoch()).count());
119*4d6fc14bSjoerg }
120*4d6fc14bSjoerg 
121*4d6fc14bSjoerg system_clock::time_point
from_time_t(time_t t)122*4d6fc14bSjoerg system_clock::from_time_t(time_t t) noexcept
123*4d6fc14bSjoerg {
124*4d6fc14bSjoerg     return system_clock::time_point(seconds(t));
125*4d6fc14bSjoerg }
126*4d6fc14bSjoerg 
127*4d6fc14bSjoerg //
128*4d6fc14bSjoerg // steady_clock
129*4d6fc14bSjoerg //
130*4d6fc14bSjoerg // Warning:  If this is not truly steady, then it is non-conforming.  It is
131*4d6fc14bSjoerg //  better for it to not exist and have the rest of libc++ use system_clock
132*4d6fc14bSjoerg //  instead.
133*4d6fc14bSjoerg //
134*4d6fc14bSjoerg 
135*4d6fc14bSjoerg #ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK
136*4d6fc14bSjoerg 
137*4d6fc14bSjoerg #if defined(__APPLE__)
138*4d6fc14bSjoerg 
139*4d6fc14bSjoerg // TODO(ldionne):
140*4d6fc14bSjoerg // This old implementation of steady_clock is retained until Chrome drops supports
141*4d6fc14bSjoerg // for macOS < 10.12. The issue is that they link libc++ statically into their
142*4d6fc14bSjoerg // application, which means that libc++ must support being built for such deployment
143*4d6fc14bSjoerg // targets. See https://llvm.org/D74489 for details.
144*4d6fc14bSjoerg #if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101200) || \
145*4d6fc14bSjoerg     (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 100000) || \
146*4d6fc14bSjoerg     (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 100000) || \
147*4d6fc14bSjoerg     (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 30000)
148*4d6fc14bSjoerg # define _LIBCPP_USE_OLD_MACH_ABSOLUTE_TIME
149*4d6fc14bSjoerg #endif
150*4d6fc14bSjoerg 
151*4d6fc14bSjoerg #if defined(_LIBCPP_USE_OLD_MACH_ABSOLUTE_TIME)
152*4d6fc14bSjoerg 
153*4d6fc14bSjoerg //   mach_absolute_time() * MachInfo.numer / MachInfo.denom is the number of
154*4d6fc14bSjoerg //   nanoseconds since the computer booted up.  MachInfo.numer and MachInfo.denom
155*4d6fc14bSjoerg //   are run time constants supplied by the OS.  This clock has no relationship
156*4d6fc14bSjoerg //   to the Gregorian calendar.  It's main use is as a high resolution timer.
157*4d6fc14bSjoerg 
158*4d6fc14bSjoerg // MachInfo.numer / MachInfo.denom is often 1 on the latest equipment.  Specialize
159*4d6fc14bSjoerg //   for that case as an optimization.
160*4d6fc14bSjoerg 
steady_simplified()161*4d6fc14bSjoerg static steady_clock::rep steady_simplified() {
162*4d6fc14bSjoerg     return static_cast<steady_clock::rep>(mach_absolute_time());
163*4d6fc14bSjoerg }
compute_steady_factor()164*4d6fc14bSjoerg static double compute_steady_factor() {
165*4d6fc14bSjoerg     mach_timebase_info_data_t MachInfo;
166*4d6fc14bSjoerg     mach_timebase_info(&MachInfo);
167*4d6fc14bSjoerg     return static_cast<double>(MachInfo.numer) / MachInfo.denom;
168*4d6fc14bSjoerg }
169*4d6fc14bSjoerg 
steady_full()170*4d6fc14bSjoerg static steady_clock::rep steady_full() {
171*4d6fc14bSjoerg     static const double factor = compute_steady_factor();
172*4d6fc14bSjoerg     return static_cast<steady_clock::rep>(mach_absolute_time() * factor);
173*4d6fc14bSjoerg }
174*4d6fc14bSjoerg 
175*4d6fc14bSjoerg typedef steady_clock::rep (*FP)();
176*4d6fc14bSjoerg 
init_steady_clock()177*4d6fc14bSjoerg static FP init_steady_clock() {
178*4d6fc14bSjoerg     mach_timebase_info_data_t MachInfo;
179*4d6fc14bSjoerg     mach_timebase_info(&MachInfo);
180*4d6fc14bSjoerg     if (MachInfo.numer == MachInfo.denom)
181*4d6fc14bSjoerg         return &steady_simplified;
182*4d6fc14bSjoerg     return &steady_full;
183*4d6fc14bSjoerg }
184*4d6fc14bSjoerg 
__libcpp_steady_clock_now()185*4d6fc14bSjoerg static steady_clock::time_point __libcpp_steady_clock_now() {
186*4d6fc14bSjoerg     static FP fp = init_steady_clock();
187*4d6fc14bSjoerg     return steady_clock::time_point(steady_clock::duration(fp()));
188*4d6fc14bSjoerg }
189*4d6fc14bSjoerg 
190*4d6fc14bSjoerg #else // vvvvv default behavior for Apple platforms  vvvvv
191*4d6fc14bSjoerg 
192*4d6fc14bSjoerg // On Apple platforms, only CLOCK_UPTIME_RAW, CLOCK_MONOTONIC_RAW or
193*4d6fc14bSjoerg // mach_absolute_time are able to time functions in the nanosecond range.
194*4d6fc14bSjoerg // Furthermore, only CLOCK_MONOTONIC_RAW is truly monotonic, because it
195*4d6fc14bSjoerg // also counts cycles when the system is asleep. Thus, it is the only
196*4d6fc14bSjoerg // acceptable implementation of steady_clock.
__libcpp_steady_clock_now()197*4d6fc14bSjoerg static steady_clock::time_point __libcpp_steady_clock_now() {
198*4d6fc14bSjoerg     struct timespec tp;
199*4d6fc14bSjoerg     if (0 != clock_gettime(CLOCK_MONOTONIC_RAW, &tp))
200*4d6fc14bSjoerg         __throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC_RAW) failed");
201*4d6fc14bSjoerg     return steady_clock::time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec));
202*4d6fc14bSjoerg }
203*4d6fc14bSjoerg 
204*4d6fc14bSjoerg #endif
205*4d6fc14bSjoerg 
206*4d6fc14bSjoerg #elif defined(_LIBCPP_WIN32API)
207*4d6fc14bSjoerg 
208*4d6fc14bSjoerg // https://msdn.microsoft.com/en-us/library/windows/desktop/ms644905(v=vs.85).aspx says:
209*4d6fc14bSjoerg //    If the function fails, the return value is zero. <snip>
210*4d6fc14bSjoerg //    On systems that run Windows XP or later, the function will always succeed
211*4d6fc14bSjoerg //      and will thus never return zero.
212*4d6fc14bSjoerg 
213*4d6fc14bSjoerg static LARGE_INTEGER
__QueryPerformanceFrequency()214*4d6fc14bSjoerg __QueryPerformanceFrequency()
215*4d6fc14bSjoerg {
216*4d6fc14bSjoerg     LARGE_INTEGER val;
217*4d6fc14bSjoerg     (void) QueryPerformanceFrequency(&val);
218*4d6fc14bSjoerg     return val;
219*4d6fc14bSjoerg }
220*4d6fc14bSjoerg 
__libcpp_steady_clock_now()221*4d6fc14bSjoerg static steady_clock::time_point __libcpp_steady_clock_now() {
222*4d6fc14bSjoerg   static const LARGE_INTEGER freq = __QueryPerformanceFrequency();
223*4d6fc14bSjoerg 
224*4d6fc14bSjoerg   LARGE_INTEGER counter;
225*4d6fc14bSjoerg   (void) QueryPerformanceCounter(&counter);
226*4d6fc14bSjoerg   auto seconds = counter.QuadPart / freq.QuadPart;
227*4d6fc14bSjoerg   auto fractions = counter.QuadPart % freq.QuadPart;
228*4d6fc14bSjoerg   auto dur = seconds * nano::den + fractions * nano::den / freq.QuadPart;
229*4d6fc14bSjoerg   return steady_clock::time_point(steady_clock::duration(dur));
230*4d6fc14bSjoerg }
231*4d6fc14bSjoerg 
232*4d6fc14bSjoerg #elif defined(__MVS__)
233*4d6fc14bSjoerg 
__libcpp_steady_clock_now()234*4d6fc14bSjoerg static steady_clock::time_point __libcpp_steady_clock_now() {
235*4d6fc14bSjoerg   struct timespec64 ts;
236*4d6fc14bSjoerg   if (0 != gettimeofdayMonotonic(&ts))
237*4d6fc14bSjoerg     __throw_system_error(errno, "failed to obtain time of day");
238*4d6fc14bSjoerg 
239*4d6fc14bSjoerg   return steady_clock::time_point(seconds(ts.tv_sec) + nanoseconds(ts.tv_nsec));
240*4d6fc14bSjoerg }
241*4d6fc14bSjoerg 
242*4d6fc14bSjoerg #elif defined(CLOCK_MONOTONIC)
243*4d6fc14bSjoerg 
__libcpp_steady_clock_now()244*4d6fc14bSjoerg static steady_clock::time_point __libcpp_steady_clock_now() {
245*4d6fc14bSjoerg     struct timespec tp;
246*4d6fc14bSjoerg     if (0 != clock_gettime(CLOCK_MONOTONIC, &tp))
247*4d6fc14bSjoerg         __throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC) failed");
248*4d6fc14bSjoerg     return steady_clock::time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec));
249*4d6fc14bSjoerg }
250*4d6fc14bSjoerg 
251*4d6fc14bSjoerg #else
252*4d6fc14bSjoerg #   error "Monotonic clock not implemented on this platform"
253*4d6fc14bSjoerg #endif
254*4d6fc14bSjoerg 
255*4d6fc14bSjoerg const bool steady_clock::is_steady;
256*4d6fc14bSjoerg 
257*4d6fc14bSjoerg steady_clock::time_point
now()258*4d6fc14bSjoerg steady_clock::now() noexcept
259*4d6fc14bSjoerg {
260*4d6fc14bSjoerg     return __libcpp_steady_clock_now();
261*4d6fc14bSjoerg }
262*4d6fc14bSjoerg 
263*4d6fc14bSjoerg #endif // !_LIBCPP_HAS_NO_MONOTONIC_CLOCK
264*4d6fc14bSjoerg 
265*4d6fc14bSjoerg }
266*4d6fc14bSjoerg 
267*4d6fc14bSjoerg _LIBCPP_END_NAMESPACE_STD
268