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  * Returns: %TRUE if the conversion was successful.
 349  *
 350  * Since: 2.12
 351  */
 352 gboolean
 353 g_time_val_from_iso8601 (const gchar *iso_date,
 354                          GTimeVal    *time_)
 355 {
 356   struct tm tm = {0};
 357   long val;
 358
 359   g_return_val_if_fail (iso_date != NULL, FALSE);
 360   g_return_val_if_fail (time_ != NULL, FALSE);
 361
 362   /* Ensure that the first character is a digit, the first digit
 363    * of the date, otherwise we don't have an ISO 8601 date
 364    */
 365   while (g_ascii_isspace (*iso_date))
 366     iso_date++;
 367
 368   if (*iso_date == '\0')
 369     return FALSE;
 370
 371   if (!g_ascii_isdigit (*iso_date) && *iso_date != '-' && *iso_date != '+')
 372     return FALSE;
 373
 374   val = strtoul (iso_date, (char **)&iso_date, 10);
 375   if (*iso_date == '-')
 376     {
 377       /* YYYY-MM-DD */
 378       tm.tm_year = val - 1900;
 379       iso_date++;
 380       tm.tm_mon = strtoul (iso_date, (char **)&iso_date, 10) - 1;
 381
 382       if (*iso_date++ != '-')
 383         return FALSE;
 384
 385       tm.tm_mday = strtoul (iso_date, (char **)&iso_date, 10);
 386     }
 387   else
 388     {
 389       /* YYYYMMDD */
 390       tm.tm_mday = val % 100;
 391       tm.tm_mon = (val % 10000) / 100 - 1;
 392       tm.tm_year = val / 10000 - 1900;
 393     }
 394
 395   if (*iso_date != 'T')
 396     return FALSE;
 397
 398   iso_date++;
 399
 400   /* If there is a 'T' then there has to be a time */
 401   if (!g_ascii_isdigit (*iso_date))
 402     return FALSE;
 403
 404   val = strtoul (iso_date, (char **)&iso_date, 10);
 405   if (*iso_date == ':')
 406     {
 407       /* hh:mm:ss */
 408       tm.tm_hour = val;
 409       iso_date++;
 410       tm.tm_min = strtoul (iso_date, (char **)&iso_date, 10);
 411
 412       if (*iso_date++ != ':')
 413         return FALSE;
 414
 415       tm.tm_sec = strtoul (iso_date, (char **)&iso_date, 10);
 416     }
 417   else
 418     {
 419       /* hhmmss */
 420       tm.tm_sec = val % 100;
 421       tm.tm_min = (val % 10000) / 100;
 422       tm.tm_hour = val / 10000;
 423     }
 424
 425   time_->tv_usec = 0;
 426
 427   if (*iso_date == ',' || *iso_date == '.')
 428     {
 429       glong mul = 100000;
 430
 431       while (g_ascii_isdigit (*++iso_date))
 432         {
 433           time_->tv_usec += (*iso_date - '0') * mul;
 434           mul /= 10;
 435         }
 436     }
 437
 438   /* Now parse the offset and convert tm to a time_t */
 439   if (*iso_date == 'Z')
 440     {
 441       iso_date++;
 442       time_->tv_sec = mktime_utc (&tm);
 443     }
 444   else if (*iso_date == '+' || *iso_date == '-')
 445     {
 446       gint sign = (*iso_date == '+') ? -1 : 1;
 447
 448       val = strtoul (iso_date + 1, (char **)&iso_date, 10);
 449
 450       if (*iso_date == ':')
 451         val = 60 * val + strtoul (iso_date + 1, (char **)&iso_date, 10);
 452       else
 453         val = 60 * (val / 100) + (val % 100);
 454
 455       time_->tv_sec = mktime_utc (&tm) + (time_t) (60 * val * sign);
 456     }
 457   else
 458     {
 459       /* No "Z" or offset, so local time */
 460       tm.tm_isdst = -1; /* locale selects DST */
 461       time_->tv_sec = mktime (&tm);
 462     }
 463
 464   while (g_ascii_isspace (*iso_date))
 465     iso_date++;
 466
 467   return *iso_date == '\0';
 468 }
 469
 470 /**
 471  * g_time_val_to_iso8601:
 472  * @time_: a #GTimeVal
 473  *
 474  * Converts @time_ into an RFC 3339 encoded string, relative to the
 475  * Coordinated Universal Time (UTC). This is one of the many formats
 476  * allowed by ISO 8601.
 477  *
 478  * ISO 8601 allows a large number of date/time formats, with or without
 479  * punctuation and optional elements. The format returned by this function
 480  * is a complete date and time, with optional punctuation included, the
 481  * UTC time zone represented as "Z", and the @tv_usec part included if
 482  * and only if it is nonzero, i.e. either
 483  * "YYYY-MM-DDTHH:MM:SSZ" or "YYYY-MM-DDTHH:MM:SS.fffffZ".
 484  *
 485  * This corresponds to the Internet date/time format defined by
 486  * [RFC 3339](https://www.ietf.org/rfc/rfc3339.txt),
 487  * and to either of the two most-precise formats defined by
 488  * the W3C Note
 489  * [Date and Time Formats](http://www.w3.org/TR/NOTE-datetime-19980827).
 490  * Both of these documents are profiles of ISO 8601.
 491  *
 492  * Use g_date_time_format() or g_strdup_printf() if a different
 493  * variation of ISO 8601 format is required.
 494  *
 495  * If @time_ represents a date which is too large to fit into a `struct tm`,
 496  * %NULL will be returned. This is platform dependent, but it is safe to assume
 497  * years up to 3000 are supported. The return value of g_time_val_to_iso8601()
 498  * has been nullable since GLib 2.54; before then, GLib would crash under the
 499  * same conditions.
 500  *
 501  * Returns: (nullable): a newly allocated string containing an ISO 8601 date,
 502  *    or %NULL if @time_ was too large
 503  *
 504  * Since: 2.12
 505  */
 506 gchar *
 507 g_time_val_to_iso8601 (GTimeVal *time_)
 508 {
 509   gchar *retval;
 510   struct tm *tm;
 511 #ifdef HAVE_GMTIME_R
 512   struct tm tm_;
 513 #endif
 514   time_t secs;
 515
 516   g_return_val_if_fail (time_->tv_usec >= 0 && time_->tv_usec < G_USEC_PER_SEC, NULL);
 517
 518   secs = time_->tv_sec;
 519 #ifdef _WIN32
 520   tm = gmtime (&secs);
 521 #else
 522 #ifdef HAVE_GMTIME_R
 523   tm = gmtime_r (&secs, &tm_);
 524 #else
 525   tm = gmtime (&secs);
 526 #endif
 527 #endif
 528
 529   /* If the gmtime() call has failed, time_->tv_sec is too big. */
 530   if (tm == NULL)
 531     return NULL;
 532
 533   if (time_->tv_usec != 0)
 534     {
 535       /* ISO 8601 date and time format, with fractionary seconds:
 536        *   YYYY-MM-DDTHH:MM:SS.MMMMMMZ
 537        */
 538       retval = g_strdup_printf ("%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ",
 539                                 tm->tm_year + 1900,
 540                                 tm->tm_mon + 1,
 541                                 tm->tm_mday,
 542                                 tm->tm_hour,
 543                                 tm->tm_min,
 544                                 tm->tm_sec,
 545                                 time_->tv_usec);
 546     }
 547   else
 548     {
 549       /* ISO 8601 date and time format:
 550        *   YYYY-MM-DDTHH:MM:SSZ
 551        */
 552       retval = g_strdup_printf ("%4d-%02d-%02dT%02d:%02d:%02dZ",
 553                                 tm->tm_year + 1900,
 554                                 tm->tm_mon + 1,
 555                                 tm->tm_mday,
 556                                 tm->tm_hour,
 557                                 tm->tm_min,
 558                                 tm->tm_sec);
 559     }
 560
 561   return retval;
 562 }