glib/gtimer.c

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  20  * file for a list of people on the GLib Team.  See the ChangeLog
  21  * files for a list of changes.  These files are distributed with
  22  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  23  */
  24
  25 /*
  26  * MT safe
  27  */
  28
  29 #include "config.h"
  30 #include "glibconfig.h"
  31
  32 #include <stdlib.h>
  33
  34 #ifdef G_OS_UNIX
  35 #include <unistd.h>
  36 #endif /* G_OS_UNIX */
  37
  38 #ifdef HAVE_SYS_TIME_H
  39 #include <sys/time.h>
  40 #endif
  41 #include <time.h>
  42 #ifndef G_OS_WIN32
  43 #include <errno.h>
  44 #endif /* G_OS_WIN32 */
  45
  46 #ifdef G_OS_WIN32
  47 #include <windows.h>
  48 #endif /* G_OS_WIN32 */
  49
  50 #include "gtimer.h"
  51
  52 #include "gmem.h"
  53 #include "gstrfuncs.h"
  54 #include "gtestutils.h"
  55 #include "gmain.h"
  56
  57 /**
  58  * SECTION:timers
  59  * @title: Timers
  60  * @short_description: keep track of elapsed time
  61  *
  62  * #GTimer records a start time, and counts microseconds elapsed since
  63  * that time. This is done somewhat differently on different platforms,
  64  * and can be tricky to get exactly right, so #GTimer provides a
  65  * portable/convenient interface.
  66  **/
  67
  68 /**
  69  * GTimer:
  70  *
  71  * Opaque datatype that records a start time.
  72  **/
  73 struct _GTimer
  74 {
  75   guint64 start;
  76   guint64 end;
  77
  78   guint active : 1;
  79 };
  80
  81 /**
  82  * g_timer_new:
  83  *
  84  * Creates a new timer, and starts timing (i.e. g_timer_start() is
  85  * implicitly called for you).
  86  *
  87  * Returns: a new #GTimer.
  88  **/
  89 GTimer*
  90 g_timer_new (void)
  91 {
  92   GTimer *timer;
  93
  94   timer = g_new (GTimer, 1);
  95   timer->active = TRUE;
  96
  97   timer->start = g_get_monotonic_time ();
  98
  99   return timer;
 100 }
 101
 102 /**
 103  * g_timer_destroy:
 104  * @timer: a #GTimer to destroy.
 105  *
 106  * Destroys a timer, freeing associated resources.
 107  **/
 108 void
 109 g_timer_destroy (GTimer *timer)
 110 {
 111   g_return_if_fail (timer != NULL);
 112
 113   g_free (timer);
 114 }
 115
 116 /**
 117  * g_timer_start:
 118  * @timer: a #GTimer.
 119  *
 120  * Marks a start time, so that future calls to g_timer_elapsed() will
 121  * report the time since g_timer_start() was called. g_timer_new()
 122  * automatically marks the start time, so no need to call
 123  * g_timer_start() immediately after creating the timer.
 124  **/
 125 void
 126 g_timer_start (GTimer *timer)
 127 {
 128   g_return_if_fail (timer != NULL);
 129
 130   timer->active = TRUE;
 131
 132   timer->start = g_get_monotonic_time ();
 133 }
 134
 135 /**
 136  * g_timer_stop:
 137  * @timer: a #GTimer.
 138  *
 139  * Marks an end time, so calls to g_timer_elapsed() will return the
 140  * difference between this end time and the start time.
 141  **/
 142 void
 143 g_timer_stop (GTimer *timer)
 144 {
 145   g_return_if_fail (timer != NULL);
 146
 147   timer->active = FALSE;
 148
 149   timer->end = g_get_monotonic_time ();
 150 }
 151
 152 /**
 153  * g_timer_reset:
 154  * @timer: a #GTimer.
 155  *
 156  * This function is useless; it's fine to call g_timer_start() on an
 157  * already-started timer to reset the start time, so g_timer_reset()
 158  * serves no purpose.
 159  **/
 160 void
 161 g_timer_reset (GTimer *timer)
 162 {
 163   g_return_if_fail (timer != NULL);
 164
 165   timer->start = g_get_monotonic_time ();
 166 }
 167
 168 /**
 169  * g_timer_continue:
 170  * @timer: a #GTimer.
 171  *
 172  * Resumes a timer that has previously been stopped with
 173  * g_timer_stop(). g_timer_stop() must be called before using this
 174  * function.
 175  *
 176  * Since: 2.4
 177  **/
 178 void
 179 g_timer_continue (GTimer *timer)
 180 {
 181   guint64 elapsed;
 182
 183   g_return_if_fail (timer != NULL);
 184   g_return_if_fail (timer->active == FALSE);
 185
 186   /* Get elapsed time and reset timer start time
 187    *  to the current time minus the previously
 188    *  elapsed interval.
 189    */
 190
 191   elapsed = timer->end - timer->start;
 192
 193   timer->start = g_get_monotonic_time ();
 194
 195   timer->start -= elapsed;
 196
 197   timer->active = TRUE;
 198 }
 199
 200 /**
 201  * g_timer_elapsed:
 202  * @timer: a #GTimer.
 203  * @microseconds: return location for the fractional part of seconds
 204  *                elapsed, in microseconds (that is, the total number
 205  *                of microseconds elapsed, modulo 1000000), or %NULL
 206  *
 207  * If @timer has been started but not stopped, obtains the time since
 208  * the timer was started. If @timer has been stopped, obtains the
 209  * elapsed time between the time it was started and the time it was
 210  * stopped. The return value is the number of seconds elapsed,
 211  * including any fractional part. The @microseconds out parameter is
 212  * essentially useless.
 213  *
 214  * Returns: seconds elapsed as a floating point value, including any
 215  *          fractional part.
 216  **/
 217 gdouble
 218 g_timer_elapsed (GTimer *timer,
 219                  gulong *microseconds)
 220 {
 221   gdouble total;
 222   gint64 elapsed;
 223
 224   g_return_val_if_fail (timer != NULL, 0);
 225
 226   if (timer->active)
 227     timer->end = g_get_monotonic_time ();
 228
 229   elapsed = timer->end - timer->start;
 230
 231   total = elapsed / 1e6;
 232
 233   if (microseconds)
 234     *microseconds = elapsed % 1000000;
 235
 236   return total;
 237 }
 238
 239 /**
 240  * g_usleep:
 241  * @microseconds: number of microseconds to pause
 242  *
 243  * Pauses the current thread for the given number of microseconds.
 244  *
 245  * There are 1 million microseconds per second (represented by the
 246  * #G_USEC_PER_SEC macro). g_usleep() may have limited precision,
 247  * depending on hardware and operating system; don't rely on the exact
 248  * length of the sleep.
 249  */
 250 void
 251 g_usleep (gulong microseconds)
 252 {
 253 #ifdef G_OS_WIN32
 254   /* Round up to the next millisecond */
 255   Sleep (microseconds ? (1 + (microseconds - 1) / 1000) : 0);
 256 #else
 257   struct timespec request, remaining;
 258   request.tv_sec = microseconds / G_USEC_PER_SEC;
 259   request.tv_nsec = 1000 * (microseconds % G_USEC_PER_SEC);
 260   while (nanosleep (&request, &remaining) == -1 && errno == EINTR)
 261     request = remaining;
 262 #endif
 263 }
 264
 265 /**
 266  * g_time_val_add:
 267  * @time_: a #GTimeVal
 268  * @microseconds: number of microseconds to add to @time
 269  *
 270  * Adds the given number of microseconds to @time_. @microseconds can
 271  * also be negative to decrease the value of @time_.
 272  **/
 273 void
 274 g_time_val_add (GTimeVal *time_, glong microseconds)
 275 {
 276   g_return_if_fail (time_->tv_usec >= 0 && time_->tv_usec < G_USEC_PER_SEC);
 277
 278   if (microseconds >= 0)
 279     {
 280       time_->tv_usec += microseconds % G_USEC_PER_SEC;
 281       time_->tv_sec += microseconds / G_USEC_PER_SEC;
 282       if (time_->tv_usec >= G_USEC_PER_SEC)
 283        {
 284          time_->tv_usec -= G_USEC_PER_SEC;
 285          time_->tv_sec++;
 286        }
 287     }
 288   else
 289     {
 290       microseconds *= -1;
 291       time_->tv_usec -= microseconds % G_USEC_PER_SEC;
 292       time_->tv_sec -= microseconds / G_USEC_PER_SEC;
 293       if (time_->tv_usec < 0)
 294        {
 295          time_->tv_usec += G_USEC_PER_SEC;
 296          time_->tv_sec--;
 297        }
 298     }
 299 }
 300
 301 /* converts a broken down date representation, relative to UTC,
 302  * to a timestamp; it uses timegm() if it's available.
 303  */
 304 static time_t
 305 mktime_utc (struct tm *tm)
 306 {
 307   time_t retval;
 308
 309 #ifndef HAVE_TIMEGM
 310   static const gint days_before[] =
 311   {
 312     0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
 313   };
 314 #endif
 315
 316 #ifndef HAVE_TIMEGM
 317   if (tm->tm_mon < 0 || tm->tm_mon > 11)
 318     return (time_t) -1;
 319
 320   retval = (tm->tm_year - 70) * 365;
 321   retval += (tm->tm_year - 68) / 4;
 322   retval += days_before[tm->tm_mon] + tm->tm_mday - 1;
 323
 324   if (tm->tm_year % 4 == 0 && tm->tm_mon < 2)
 325     retval -= 1;
 326
 327   retval = ((((retval * 24) + tm->tm_hour) * 60) + tm->tm_min) * 60 + tm->tm_sec;
 328 #else
 329   retval = timegm (tm);
 330 #endif /* !HAVE_TIMEGM */
 331
 332   return retval;
 333 }
 334
 335 /**
 336  * g_time_val_from_iso8601:
 337  * @iso_date: an ISO 8601 encoded date string
 338  * @time_: (out): a #GTimeVal
 339  *
 340  * Converts a string containing an ISO 8601 encoded date and time
 341  * to a #GTimeVal and puts it into @time_.
 342  *
 343  * @iso_date must include year, month, day, hours, minutes, and
 344  * seconds. It can optionally include fractions of a second and a time
 345  * zone indicator. (In the absence of any time zone indication, the
 346  * timestamp is assumed to be in local time.)
 347  *
 348  * Any leading or trailing space in @iso_date is ignored.
 349  *
 350  * Returns: %TRUE if the conversion was successful.
 351  *
 352  * Since: 2.12
 353  */
 354 gboolean
 355 g_time_val_from_iso8601 (const gchar *iso_date,
 356                          GTimeVal    *time_)
 357 {
 358   struct tm tm = {0};
 359   long val;
 360   long mday, mon, year;
 361   long hour, min, sec;
 362
 363   g_return_val_if_fail (iso_date != NULL, FALSE);
 364   g_return_val_if_fail (time_ != NULL, FALSE);
 365
 366   /* Ensure that the first character is a digit, the first digit
 367    * of the date, otherwise we don't have an ISO 8601 date
 368    */
 369   while (g_ascii_isspace (*iso_date))
 370     iso_date++;
 371
 372   if (*iso_date == '\0')
 373     return FALSE;
 374
 375   if (!g_ascii_isdigit (*iso_date) && *iso_date != '+')
 376     return FALSE;
 377
 378   val = strtoul (iso_date, (char **)&iso_date, 10);
 379   if (*iso_date == '-')
 380     {
 381       /* YYYY-MM-DD */
 382       year = val;
 383       iso_date++;
 384
 385       mon = strtoul (iso_date, (char **)&iso_date, 10);
 386       if (*iso_date++ != '-')
 387         return FALSE;
 388
 389       mday = strtoul (iso_date, (char **)&iso_date, 10);
 390     }
 391   else
 392     {
 393       /* YYYYMMDD */
 394       mday = val % 100;
 395       mon = (val % 10000) / 100;
 396       year = val / 10000;
 397     }
 398
 399   /* Validation. */
 400   if (year < 1900 || year > G_MAXINT)
 401     return FALSE;
 402   if (mon < 1 || mon > 12)
 403     return FALSE;
 404   if (mday < 1 || mday > 31)
 405     return FALSE;
 406
 407   tm.tm_mday = mday;
 408   tm.tm_mon = mon - 1;
 409   tm.tm_year = year - 1900;
 410
 411   if (*iso_date != 'T')
 412     return FALSE;
 413
 414   iso_date++;
 415
 416   /* If there is a 'T' then there has to be a time */
 417   if (!g_ascii_isdigit (*iso_date))
 418     return FALSE;
 419
 420   val = strtoul (iso_date, (char **)&iso_date, 10);
 421   if (*iso_date == ':')
 422     {
 423       /* hh:mm:ss */
 424       hour = val;
 425       iso_date++;
 426       min = strtoul (iso_date, (char **)&iso_date, 10);
 427
 428       if (*iso_date++ != ':')
 429         return FALSE;
 430
 431       sec = strtoul (iso_date, (char **)&iso_date, 10);
 432     }
 433   else
 434     {
 435       /* hhmmss */
 436       sec = val % 100;
 437       min = (val % 10000) / 100;
 438       hour = val / 10000;
 439     }
 440
 441   /* Validation. Allow up to 2 leap seconds when validating @sec. */
 442   if (hour > 23)
 443     return FALSE;
 444   if (min > 59)
 445     return FALSE;
 446   if (sec > 61)
 447     return FALSE;
 448
 449   tm.tm_hour = hour;
 450   tm.tm_min = min;
 451   tm.tm_sec = sec;
 452
 453   time_->tv_usec = 0;
 454
 455   if (*iso_date == ',' || *iso_date == '.')
 456     {
 457       glong mul = 100000;
 458
 459       while (mul >= 1 && g_ascii_isdigit (*++iso_date))
 460         {
 461           time_->tv_usec += (*iso_date - '0') * mul;
 462           mul /= 10;
 463         }
 464
 465       /* Skip any remaining digits after we’ve reached our limit of precision. */
 466       while (g_ascii_isdigit (*iso_date))
 467         iso_date++;
 468     }
 469
 470   /* Now parse the offset and convert tm to a time_t */
 471   if (*iso_date == 'Z')
 472     {
 473       iso_date++;
 474       time_->tv_sec = mktime_utc (&tm);
 475     }
 476   else if (*iso_date == '+' || *iso_date == '-')
 477     {
 478       gint sign = (*iso_date == '+') ? -1 : 1;
 479
 480       val = strtoul (iso_date + 1, (char **)&iso_date, 10);
 481
 482       if (*iso_date == ':')
 483         {
 484           /* hh:mm */
 485           hour = val;
 486           min = strtoul (iso_date + 1, (char **)&iso_date, 10);
 487         }
 488       else
 489         {
 490           /* hhmm */
 491           hour = val / 100;
 492           min = val % 100;
 493         }
 494
 495       if (hour > 99)
 496         return FALSE;
 497       if (min > 59)
 498         return FALSE;
 499
 500       time_->tv_sec = mktime_utc (&tm) + (time_t) (60 * (gint64) (60 * hour + min) * sign);
 501     }
 502   else
 503     {
 504       /* No "Z" or offset, so local time */
 505       tm.tm_isdst = -1; /* locale selects DST */
 506       time_->tv_sec = mktime (&tm);
 507     }
 508
 509   while (g_ascii_isspace (*iso_date))
 510     iso_date++;
 511
 512   return *iso_date == '\0';
 513 }
 514
 515 /**
 516  * g_time_val_to_iso8601:
 517  * @time_: a #GTimeVal
 518  *
 519  * Converts @time_ into an RFC 3339 encoded string, relative to the
 520  * Coordinated Universal Time (UTC). This is one of the many formats
 521  * allowed by ISO 8601.
 522  *
 523  * ISO 8601 allows a large number of date/time formats, with or without
 524  * punctuation and optional elements. The format returned by this function
 525  * is a complete date and time, with optional punctuation included, the
 526  * UTC time zone represented as "Z", and the @tv_usec part included if
 527  * and only if it is nonzero, i.e. either
 528  * "YYYY-MM-DDTHH:MM:SSZ" or "YYYY-MM-DDTHH:MM:SS.fffffZ".
 529  *
 530  * This corresponds to the Internet date/time format defined by
 531  * [RFC 3339](https://www.ietf.org/rfc/rfc3339.txt),
 532  * and to either of the two most-precise formats defined by
 533  * the W3C Note
 534  * [Date and Time Formats](http://www.w3.org/TR/NOTE-datetime-19980827).
 535  * Both of these documents are profiles of ISO 8601.
 536  *
 537  * Use g_date_time_format() or g_strdup_printf() if a different
 538  * variation of ISO 8601 format is required.
 539  *
 540  * If @time_ represents a date which is too large to fit into a `struct tm`,
 541  * %NULL will be returned. This is platform dependent, but it is safe to assume
 542  * years up to 3000 are supported. The return value of g_time_val_to_iso8601()
 543  * has been nullable since GLib 2.54; before then, GLib would crash under the
 544  * same conditions.
 545  *
 546  * Returns: (nullable): a newly allocated string containing an ISO 8601 date,
 547  *    or %NULL if @time_ was too large
 548  *
 549  * Since: 2.12
 550  */
 551 gchar *
 552 g_time_val_to_iso8601 (GTimeVal *time_)
 553 {
 554   gchar *retval;
 555   struct tm *tm;
 556 #ifdef HAVE_GMTIME_R
 557   struct tm tm_;
 558 #endif
 559   time_t secs;
 560
 561   g_return_val_if_fail (time_->tv_usec >= 0 && time_->tv_usec < G_USEC_PER_SEC, NULL);
 562
 563   secs = time_->tv_sec;
 564 #ifdef _WIN32
 565   tm = gmtime (&secs);
 566 #else
 567 #ifdef HAVE_GMTIME_R
 568   tm = gmtime_r (&secs, &tm_);
 569 #else
 570   tm = gmtime (&secs);
 571 #endif
 572 #endif
 573
 574   /* If the gmtime() call has failed, time_->tv_sec is too big. */
 575   if (tm == NULL)
 576     return NULL;
 577
 578   if (time_->tv_usec != 0)
 579     {
 580       /* ISO 8601 date and time format, with fractionary seconds:
 581        *   YYYY-MM-DDTHH:MM:SS.MMMMMMZ
 582        */
 583       retval = g_strdup_printf ("%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ",
 584                                 tm->tm_year + 1900,
 585                                 tm->tm_mon + 1,
 586                                 tm->tm_mday,
 587                                 tm->tm_hour,
 588                                 tm->tm_min,
 589                                 tm->tm_sec,
 590                                 time_->tv_usec);
 591     }
 592   else
 593     {
 594       /* ISO 8601 date and time format:
 595        *   YYYY-MM-DDTHH:MM:SSZ
 596        */
 597       retval = g_strdup_printf ("%4d-%02d-%02dT%02d:%02d:%02dZ",
 598                                 tm->tm_year + 1900,
 599                                 tm->tm_mon + 1,
 600                                 tm->tm_mday,
 601                                 tm->tm_hour,
 602                                 tm->tm_min,
 603                                 tm->tm_sec);
 604     }
 605
 606   return retval;
 607 }