1/* Implementation of the SYSTEM_CLOCK intrinsic. 2 Copyright (C) 2004-2020 Free Software Foundation, Inc. 3 4This file is part of the GNU Fortran runtime library (libgfortran). 5 6Libgfortran is free software; you can redistribute it and/or 7modify it under the terms of the GNU General Public 8License as published by the Free Software Foundation; either 9version 3 of the License, or (at your option) any later version. 10 11Libgfortran is distributed in the hope that it will be useful, 12but WITHOUT ANY WARRANTY; without even the implied warranty of 13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14GNU General Public License for more details. 15 16Under Section 7 of GPL version 3, you are granted additional 17permissions described in the GCC Runtime Library Exception, version 183.1, as published by the Free Software Foundation. 19 20You should have received a copy of the GNU General Public License and 21a copy of the GCC Runtime Library Exception along with this program; 22see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23<http://www.gnu.org/licenses/>. */ 24 25#include "libgfortran.h" 26 27#include <limits.h> 28 29#include "time_1.h" 30 31 32#if !defined(__MINGW32__) 33 34/* POSIX states that CLOCK_REALTIME must be present if clock_gettime 35 is available, others are optional. */ 36#if defined(HAVE_CLOCK_GETTIME) || defined(HAVE_CLOCK_GETTIME_LIBRT) 37#if defined(CLOCK_MONOTONIC) && defined(_POSIX_MONOTONIC_CLOCK) \ 38 && _POSIX_MONOTONIC_CLOCK >= 0 39#define GF_CLOCK_MONOTONIC CLOCK_MONOTONIC 40#else 41#define GF_CLOCK_MONOTONIC CLOCK_REALTIME 42#endif 43#endif 44 45/* Weakref trickery for clock_gettime(). On Glibc <= 2.16, 46 clock_gettime() requires us to link in librt, which also pulls in 47 libpthread. In order to avoid this by default, only call 48 clock_gettime() through a weak reference. */ 49#if SUPPORTS_WEAKREF && defined(HAVE_CLOCK_GETTIME_LIBRT) 50static int weak_gettime (clockid_t, struct timespec *) 51 __attribute__((__weakref__("clock_gettime"))); 52#endif 53 54 55/* High resolution monotonic clock, falling back to the realtime clock 56 if the target does not support such a clock. 57 58 Arguments: 59 secs - OUTPUT, seconds 60 fracsecs - OUTPUT, fractional seconds, units given by tk argument 61 tk - OUTPUT, clock resolution [counts/sec] 62 63 If the target supports a monotonic clock, the OUTPUT arguments 64 represent a monotonically incrementing clock starting from some 65 unspecified time in the past. 66 67 If a monotonic clock is not available, falls back to the realtime 68 clock which is not monotonic. 69 70 Return value: 0 for success, -1 for error. In case of error, errno 71 is set. 72*/ 73static int 74gf_gettime_mono (time_t * secs, long * fracsecs, long * tck) 75{ 76 int err; 77#ifdef HAVE_CLOCK_GETTIME 78 struct timespec ts; 79 *tck = 1000000000; 80 err = clock_gettime (GF_CLOCK_MONOTONIC, &ts); 81 *secs = ts.tv_sec; 82 *fracsecs = ts.tv_nsec; 83 return err; 84#else 85#if SUPPORTS_WEAKREF && defined(HAVE_CLOCK_GETTIME_LIBRT) 86 if (weak_gettime) 87 { 88 struct timespec ts; 89 *tck = 1000000000; 90 err = weak_gettime (GF_CLOCK_MONOTONIC, &ts); 91 *secs = ts.tv_sec; 92 *fracsecs = ts.tv_nsec; 93 return err; 94 } 95#endif 96 *tck = 1000000; 97 err = gf_gettime (secs, fracsecs); 98 return err; 99#endif 100} 101 102#endif /* !__MINGW32__ */ 103 104extern void 105system_clock_4 (GFC_INTEGER_4 *count, GFC_INTEGER_4 *count_rate, 106 GFC_INTEGER_4 *count_max); 107export_proto(system_clock_4); 108 109extern void 110system_clock_8 (GFC_INTEGER_8 *count, GFC_INTEGER_8 *count_rate, 111 GFC_INTEGER_8 *count_max); 112export_proto(system_clock_8); 113 114 115/* prefix(system_clock_4) is the INTEGER(4) version of the SYSTEM_CLOCK 116 intrinsic subroutine. It returns the number of clock ticks for the current 117 system time, the number of ticks per second, and the maximum possible value 118 for COUNT. */ 119 120void 121system_clock_4 (GFC_INTEGER_4 *count, GFC_INTEGER_4 *count_rate, 122 GFC_INTEGER_4 *count_max) 123{ 124#if defined(__MINGW32__) 125 if (count) 126 { 127 /* Use GetTickCount here as the resolution and range is 128 sufficient for the INTEGER(kind=4) version, and 129 QueryPerformanceCounter has potential issues. */ 130 uint32_t cnt = GetTickCount (); 131 if (cnt > GFC_INTEGER_4_HUGE) 132 cnt = cnt - GFC_INTEGER_4_HUGE - 1; 133 *count = cnt; 134 } 135 if (count_rate) 136 *count_rate = 1000; 137 if (count_max) 138 *count_max = GFC_INTEGER_4_HUGE; 139#else 140 time_t secs; 141 long fracsecs, tck; 142 143 if (gf_gettime_mono (&secs, &fracsecs, &tck) == 0) 144 { 145 long tck_out = tck > 1000 ? 1000 : tck; 146 long tck_r = tck / tck_out; 147 GFC_UINTEGER_4 ucnt = (GFC_UINTEGER_4) secs * tck_out; 148 ucnt += fracsecs / tck_r; 149 if (ucnt > GFC_INTEGER_4_HUGE) 150 ucnt = ucnt - GFC_INTEGER_4_HUGE - 1; 151 if (count) 152 *count = ucnt; 153 if (count_rate) 154 *count_rate = tck_out; 155 if (count_max) 156 *count_max = GFC_INTEGER_4_HUGE; 157 } 158 else 159 { 160 if (count) 161 *count = - GFC_INTEGER_4_HUGE; 162 if (count_rate) 163 *count_rate = 0; 164 if (count_max) 165 *count_max = 0; 166 } 167#endif 168} 169 170 171/* INTEGER(8) version of the above routine. */ 172 173void 174system_clock_8 (GFC_INTEGER_8 *count, GFC_INTEGER_8 *count_rate, 175 GFC_INTEGER_8 *count_max) 176{ 177#if defined(__MINGW32__) 178 LARGE_INTEGER cnt; 179 LARGE_INTEGER freq; 180 bool fail = false; 181 if (count && !QueryPerformanceCounter (&cnt)) 182 fail = true; 183 if (count_rate && !QueryPerformanceFrequency (&freq)) 184 fail = true; 185 if (fail) 186 { 187 if (count) 188 *count = - GFC_INTEGER_8_HUGE; 189 if (count_rate) 190 *count_rate = 0; 191 if (count_max) 192 *count_max = 0; 193 } 194 else 195 { 196 if (count) 197 *count = cnt.QuadPart; 198 if (count_rate) 199 *count_rate = freq.QuadPart; 200 if (count_max) 201 *count_max = GFC_INTEGER_8_HUGE; 202 } 203#else 204 time_t secs; 205 long fracsecs, tck; 206 207 if (gf_gettime_mono (&secs, &fracsecs, &tck) == 0) 208 { 209 GFC_UINTEGER_8 ucnt = (GFC_UINTEGER_8) secs * tck; 210 ucnt += fracsecs; 211 if (ucnt > GFC_INTEGER_8_HUGE) 212 ucnt = ucnt - GFC_INTEGER_8_HUGE - 1; 213 if (count) 214 *count = ucnt; 215 if (count_rate) 216 *count_rate = tck; 217 if (count_max) 218 *count_max = GFC_INTEGER_8_HUGE; 219 } 220 else 221 { 222 if (count) 223 *count = - GFC_INTEGER_8_HUGE; 224 if (count_rate) 225 *count_rate = 0; 226 if (count_max) 227 *count_max = 0; 228 } 229#endif 230} 231