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   Sleep (microseconds / 1000);
 255 #else
 256   struct timespec request, remaining;
 257   request.tv_sec = microseconds / G_USEC_PER_SEC;
 258   request.tv_nsec = 1000 * (microseconds % G_USEC_PER_SEC);
 259   while (nanosleep (&request, &remaining) == -1 && errno == EINTR)
 260     request = remaining;
 261 #endif
 262 }
 263
 264 /**
 265  * g_time_val_add:
 266  * @time_: a #GTimeVal
 267  * @microseconds: number of microseconds to add to @time
 268  *
 269  * Adds the given number of microseconds to @time_. @microseconds can
 270  * also be negative to decrease the value of @time_.
 271  **/
 272 void
 273 g_time_val_add (GTimeVal *time_, glong microseconds)
 274 {
 275   g_return_if_fail (time_->tv_usec >= 0 && time_->tv_usec < G_USEC_PER_SEC);
 276
 277   if (microseconds >= 0)
 278     {
 279       time_->tv_usec += microseconds % G_USEC_PER_SEC;
 280       time_->tv_sec += microseconds / G_USEC_PER_SEC;
 281       if (time_->tv_usec >= G_USEC_PER_SEC)
 282        {
 283          time_->tv_usec -= G_USEC_PER_SEC;
 284          time_->tv_sec++;
 285        }
 286     }
 287   else
 288     {
 289       microseconds *= -1;
 290       time_->tv_usec -= microseconds % G_USEC_PER_SEC;
 291       time_->tv_sec -= microseconds / G_USEC_PER_SEC;
 292       if (time_->tv_usec < 0)
 293        {
 294          time_->tv_usec += G_USEC_PER_SEC;
 295          time_->tv_sec--;
 296        }
 297     }
 298 }
 299
 300 /* converts a broken down date representation, relative to UTC,
 301  * to a timestamp; it uses timegm() if it's available.
 302  */
 303 static time_t
 304 mktime_utc (struct tm *tm)
 305 {
 306   time_t retval;
 307
 308 #ifndef HAVE_TIMEGM
 309   static const gint days_before[] =
 310   {
 311     0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
 312   };
 313 #endif
 314
 315 #ifndef HAVE_TIMEGM
 316   if (tm->tm_mon < 0 || tm->tm_mon > 11)
 317     return (time_t) -1;
 318
 319   retval = (tm->tm_year - 70) * 365;
 320   retval += (tm->tm_year - 68) / 4;
 321   retval += days_before[tm->tm_mon] + tm->tm_mday - 1;
 322
 323   if (tm->tm_year % 4 == 0 && tm->tm_mon < 2)
 324     retval -= 1;
 325
 326   retval = ((((retval * 24) + tm->tm_hour) * 60) + tm->tm_min) * 60 + tm->tm_sec;
 327 #else
 328   retval = timegm (tm);
 329 #endif /* !HAVE_TIMEGM */
 330
 331   return retval;
 332 }
 333
 334 /**
 335  * g_time_val_from_iso8601:
 336  * @iso_date: an ISO 8601 encoded date string
 337  * @time_: (out): a #GTimeVal
 338  *
 339  * Converts a string containing an ISO 8601 encoded date and time
 340  * to a #GTimeVal and puts it into @time_.
 341  *
 342  * @iso_date must include year, month, day, hours, minutes, and
 343  * seconds. It can optionally include fractions of a second and a time
 344  * zone indicator. (In the absence of any time zone indication, the
 345  * timestamp is assumed to be in local time.)
 346  *
 347  * Returns: %TRUE if the conversion was successful.
 348  *
 349  * Since: 2.12
 350  */
 351 gboolean
 352 g_time_val_from_iso8601 (const gchar *iso_date,
 353                          GTimeVal    *time_)
 354 {
 355   struct tm tm = {0};
 356   long val;
 357
 358   g_return_val_if_fail (iso_date != NULL, FALSE);
 359   g_return_val_if_fail (time_ != NULL, FALSE);
 360
 361   /* Ensure that the first character is a digit, the first digit
 362    * of the date, otherwise we don't have an ISO 8601 date
 363    */
 364   while (g_ascii_isspace (*iso_date))
 365     iso_date++;
 366
 367   if (*iso_date == '\0')
 368     return FALSE;
 369
 370   if (!g_ascii_isdigit (*iso_date) && *iso_date != '-' && *iso_date != '+')
 371     return FALSE;
 372
 373   val = strtoul (iso_date, (char **)&iso_date, 10);
 374   if (*iso_date == '-')
 375     {
 376       /* YYYY-MM-DD */
 377       tm.tm_year = val - 1900;
 378       iso_date++;
 379       tm.tm_mon = strtoul (iso_date, (char **)&iso_date, 10) - 1;
 380
 381       if (*iso_date++ != '-')
 382         return FALSE;
 383
 384       tm.tm_mday = strtoul (iso_date, (char **)&iso_date, 10);
 385     }
 386   else
 387     {
 388       /* YYYYMMDD */
 389       tm.tm_mday = val % 100;
 390       tm.tm_mon = (val % 10000) / 100 - 1;
 391       tm.tm_year = val / 10000 - 1900;
 392     }
 393
 394   if (*iso_date != 'T')
 395     return FALSE;
 396
 397   iso_date++;
 398
 399   /* If there is a 'T' then there has to be a time */
 400   if (!g_ascii_isdigit (*iso_date))
 401     return FALSE;
 402
 403   val = strtoul (iso_date, (char **)&iso_date, 10);
 404   if (*iso_date == ':')
 405     {
 406       /* hh:mm:ss */
 407       tm.tm_hour = val;
 408       iso_date++;
 409       tm.tm_min = strtoul (iso_date, (char **)&iso_date, 10);
 410
 411       if (*iso_date++ != ':')
 412         return FALSE;
 413
 414       tm.tm_sec = strtoul (iso_date, (char **)&iso_date, 10);
 415     }
 416   else
 417     {
 418       /* hhmmss */
 419       tm.tm_sec = val % 100;
 420       tm.tm_min = (val % 10000) / 100;
 421       tm.tm_hour = val / 10000;
 422     }
 423
 424   time_->tv_usec = 0;
 425
 426   if (*iso_date == ',' || *iso_date == '.')
 427     {
 428       glong mul = 100000;
 429
 430       while (g_ascii_isdigit (*++iso_date))
 431         {
 432           time_->tv_usec += (*iso_date - '0') * mul;
 433           mul /= 10;
 434         }
 435     }
 436
 437   /* Now parse the offset and convert tm to a time_t */
 438   if (*iso_date == 'Z')
 439     {
 440       iso_date++;
 441       time_->tv_sec = mktime_utc (&tm);
 442     }
 443   else if (*iso_date == '+' || *iso_date == '-')
 444     {
 445       gint sign = (*iso_date == '+') ? -1 : 1;
 446
 447       val = strtoul (iso_date + 1, (char **)&iso_date, 10);
 448
 449       if (*iso_date == ':')
 450         val = 60 * val + strtoul (iso_date + 1, (char **)&iso_date, 10);
 451       else
 452         val = 60 * (val / 100) + (val % 100);
 453
 454       time_->tv_sec = mktime_utc (&tm) + (time_t) (60 * val * sign);
 455     }
 456   else
 457     {
 458       /* No "Z" or offset, so local time */
 459       tm.tm_isdst = -1; /* locale selects DST */
 460       time_->tv_sec = mktime (&tm);
 461     }
 462
 463   while (g_ascii_isspace (*iso_date))
 464     iso_date++;
 465
 466   return *iso_date == '\0';
 467 }
 468
 469 /**
 470  * g_time_val_to_iso8601:
 471  * @time_: a #GTimeVal
 472  *
 473  * Converts @time_ into an RFC 3339 encoded string, relative to the
 474  * Coordinated Universal Time (UTC). This is one of the many formats
 475  * allowed by ISO 8601.
 476  *
 477  * ISO 8601 allows a large number of date/time formats, with or without
 478  * punctuation and optional elements. The format returned by this function
 479  * is a complete date and time, with optional punctuation included, the
 480  * UTC time zone represented as "Z", and the @tv_usec part included if
 481  * and only if it is nonzero, i.e. either
 482  * "YYYY-MM-DDTHH:MM:SSZ" or "YYYY-MM-DDTHH:MM:SS.fffffZ".
 483  *
 484  * This corresponds to the Internet date/time format defined by
 485  * [RFC 3339](https://www.ietf.org/rfc/rfc3339.txt),
 486  * and to either of the two most-precise formats defined by
 487  * the W3C Note
 488  * [Date and Time Formats](http://www.w3.org/TR/NOTE-datetime-19980827).
 489  * Both of these documents are profiles of ISO 8601.
 490  *
 491  * Use g_date_time_format() or g_strdup_printf() if a different
 492  * variation of ISO 8601 format is required.
 493  *
 494  * If @time_ represents a date which is too large to fit into a `struct tm`,
 495  * %NULL will be returned. This is platform dependent, but it is safe to assume
 496  * years up to 3000 are supported. The return value of g_time_val_to_iso8601()
 497  * has been nullable since GLib 2.54; before then, GLib would crash under the
 498  * same conditions.
 499  *
 500  * Returns: (nullable): a newly allocated string containing an ISO 8601 date,
 501  *    or %NULL if @time_ was too large
 502  *
 503  * Since: 2.12
 504  */
 505 gchar *
 506 g_time_val_to_iso8601 (GTimeVal *time_)
 507 {
 508   gchar *retval;
 509   struct tm *tm;
 510 #ifdef HAVE_GMTIME_R
 511   struct tm tm_;
 512 #endif
 513   time_t secs;
 514
 515   g_return_val_if_fail (time_->tv_usec >= 0 && time_->tv_usec < G_USEC_PER_SEC, NULL);
 516
 517   secs = time_->tv_sec;
 518 #ifdef _WIN32
 519   tm = gmtime (&secs);
 520 #else
 521 #ifdef HAVE_GMTIME_R
 522   tm = gmtime_r (&secs, &tm_);
 523 #else
 524   tm = gmtime (&secs);
 525 #endif
 526 #endif
 527
 528   /* If the gmtime() call has failed, time_->tv_sec is too big. */
 529   if (tm == NULL)
 530     return NULL;
 531
 532   if (time_->tv_usec != 0)
 533     {
 534       /* ISO 8601 date and time format, with fractionary seconds:
 535        *   YYYY-MM-DDTHH:MM:SS.MMMMMMZ
 536        */
 537       retval = g_strdup_printf ("%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ",
 538                                 tm->tm_year + 1900,
 539                                 tm->tm_mon + 1,
 540                                 tm->tm_mday,
 541                                 tm->tm_hour,
 542                                 tm->tm_min,
 543                                 tm->tm_sec,
 544                                 time_->tv_usec);
 545     }
 546   else
 547     {
 548       /* ISO 8601 date and time format:
 549        *   YYYY-MM-DDTHH:MM:SSZ
 550        */
 551       retval = g_strdup_printf ("%4d-%02d-%02dT%02d:%02d:%02dZ",
 552                                 tm->tm_year + 1900,
 553                                 tm->tm_mon + 1,
 554                                 tm->tm_mday,
 555                                 tm->tm_hour,
 556                                 tm->tm_min,
 557                                 tm->tm_sec);
 558     }
 559
 560   return retval;
 561 }