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 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, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GLib Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 /*
  28  * MT safe
  29  */
  30
  31 #include "config.h"
  32 #include "glibconfig.h"
  33
  34 #include <stdlib.h>
  35
  36 #ifdef HAVE_UNISTD_H
  37 #include <unistd.h>
  38 #endif /* HAVE_UNISTD_H */
  39
  40 #ifndef G_OS_WIN32
  41 #include <sys/time.h>
  42 #include <time.h>
  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 "glib.h"
  51 #include "gthread.h"
  52 #include "galias.h"
  53
  54 /**
  55  * SECTION: timers
  56  * @title: Timers
  57  * @short_description: keep track of elapsed time
  58  *
  59  * #GTimer records a start time, and counts microseconds elapsed since
  60  * that time. This is done somewhat differently on different platforms,
  61  * and can be tricky to get exactly right, so #GTimer provides a
  62  * portable/convenient interface.
  63  *
  64  * <note><para>
  65  *  #GTimer uses a higher-quality clock when thread support is available.
  66  *  Therefore, calling g_thread_init() while timers are running may lead to
  67  *  unreliable results. It is best to call g_thread_init() before starting any
  68  *  timers, if you are using threads at all.
  69  * </para></note>
  70  **/
  71
  72 #define G_NSEC_PER_SEC 1000000000
  73
  74 #define GETTIME(v) (v = g_thread_gettime ())
  75
  76 /**
  77  * GTimer:
  78  *
  79  * Opaque datatype that records a start time.
  80  **/
  81 struct _GTimer
  82 {
  83   guint64 start;
  84   guint64 end;
  85
  86   guint active : 1;
  87 };
  88
  89 /**
  90  * g_timer_new:
  91  * @Returns: a new #GTimer.
  92  *
  93  * Creates a new timer, and starts timing (i.e. g_timer_start() is
  94  * implicitly called for you).
  95  **/
  96 GTimer*
  97 g_timer_new (void)
  98 {
  99   GTimer *timer;
 100
 101   timer = g_new (GTimer, 1);
 102   timer->active = TRUE;
 103
 104   GETTIME (timer->start);
 105
 106   return timer;
 107 }
 108
 109 /**
 110  * g_timer_destroy:
 111  * @timer: a #GTimer to destroy.
 112  *
 113  * Destroys a timer, freeing associated resources.
 114  **/
 115 void
 116 g_timer_destroy (GTimer *timer)
 117 {
 118   g_return_if_fail (timer != NULL);
 119
 120   g_free (timer);
 121 }
 122
 123 /**
 124  * g_timer_start:
 125  * @timer: a #GTimer.
 126  *
 127  * Marks a start time, so that future calls to g_timer_elapsed() will
 128  * report the time since g_timer_start() was called. g_timer_new()
 129  * automatically marks the start time, so no need to call
 130  * g_timer_start() immediately after creating the timer.
 131  **/
 132 void
 133 g_timer_start (GTimer *timer)
 134 {
 135   g_return_if_fail (timer != NULL);
 136
 137   timer->active = TRUE;
 138
 139   GETTIME (timer->start);
 140 }
 141
 142 /**
 143  * g_timer_stop:
 144  * @timer: a #GTimer.
 145  *
 146  * Marks an end time, so calls to g_timer_elapsed() will return the
 147  * difference between this end time and the start time.
 148  **/
 149 void
 150 g_timer_stop (GTimer *timer)
 151 {
 152   g_return_if_fail (timer != NULL);
 153
 154   timer->active = FALSE;
 155
 156   GETTIME (timer->end);
 157 }
 158
 159 /**
 160  * g_timer_reset:
 161  * @timer: a #GTimer.
 162  *
 163  * This function is useless; it's fine to call g_timer_start() on an
 164  * already-started timer to reset the start time, so g_timer_reset()
 165  * serves no purpose.
 166  **/
 167 void
 168 g_timer_reset (GTimer *timer)
 169 {
 170   g_return_if_fail (timer != NULL);
 171
 172   GETTIME (timer->start);
 173 }
 174
 175 /**
 176  * g_timer_continue:
 177  * @timer: a #GTimer.
 178  *
 179  * Resumes a timer that has previously been stopped with
 180  * g_timer_stop(). g_timer_stop() must be called before using this
 181  * function.
 182  *
 183  * Since: 2.4
 184  **/
 185 void
 186 g_timer_continue (GTimer *timer)
 187 {
 188   guint64 elapsed;
 189
 190   g_return_if_fail (timer != NULL);
 191   g_return_if_fail (timer->active == FALSE);
 192
 193   /* Get elapsed time and reset timer start time
 194    *  to the current time minus the previously
 195    *  elapsed interval.
 196    */
 197
 198   elapsed = timer->end - timer->start;
 199
 200   GETTIME (timer->start);
 201
 202   timer->start -= elapsed;
 203
 204   timer->active = TRUE;
 205 }
 206
 207 /**
 208  * g_timer_elapsed:
 209  * @timer: a #GTimer.
 210  * @microseconds: return location for the fractional part of seconds
 211  *                elapsed, in microseconds (that is, the total number
 212  *                of microseconds elapsed, modulo 1000000), or %NULL
 213  * @Returns: seconds elapsed as a floating point value, including any
 214  *           fractional part.
 215  *
 216  * If @timer has been started but not stopped, obtains the time since
 217  * the timer was started. If @timer has been stopped, obtains the
 218  * elapsed time between the time it was started and the time it was
 219  * stopped. The return value is the number of seconds elapsed,
 220  * including any fractional part. The @microseconds out parameter is
 221  * essentially useless.
 222  *
 223  * <warning><para>
 224  *  Calling initialization functions, in particular g_thread_init(), while a
 225  *  timer is running will cause invalid return values from this function.
 226  * </para></warning>
 227  **/
 228 gdouble
 229 g_timer_elapsed (GTimer *timer,
 230                  gulong *microseconds)
 231 {
 232   gdouble total;
 233   gint64 elapsed;
 234
 235   g_return_val_if_fail (timer != NULL, 0);
 236
 237   if (timer->active)
 238     GETTIME (timer->end);
 239
 240   elapsed = timer->end - timer->start;
 241
 242   total = elapsed / 1e9;
 243
 244   if (microseconds)
 245     *microseconds = (elapsed / 1000) % 1000000;
 246
 247   return total;
 248 }
 249
 250 void
 251 g_usleep (gulong microseconds)
 252 {
 253 #ifdef G_OS_WIN32
 254   Sleep (microseconds / 1000);
 255 #else /* !G_OS_WIN32 */
 256 # ifdef HAVE_NANOSLEEP
 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 # else /* !HAVE_NANOSLEEP */
 263 #  ifdef HAVE_NSLEEP
 264   /* on AIX, nsleep is analogous to nanosleep */
 265   struct timespec request, remaining;
 266   request.tv_sec = microseconds / G_USEC_PER_SEC;
 267   request.tv_nsec = 1000 * (microseconds % G_USEC_PER_SEC);
 268   while (nsleep (&request, &remaining) == -1 && errno == EINTR)
 269     request = remaining;
 270 #  else /* !HAVE_NSLEEP */
 271   if (g_thread_supported ())
 272     {
 273       static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
 274       static GCond* cond = NULL;
 275       GTimeVal end_time;
 276
 277       g_get_current_time (&end_time);
 278       if (microseconds > G_MAXLONG)
 279         {
 280           microseconds -= G_MAXLONG;
 281           g_time_val_add (&end_time, G_MAXLONG);
 282         }
 283       g_time_val_add (&end_time, microseconds);
 284
 285       g_static_mutex_lock (&mutex);
 286
 287       if (!cond)
 288         cond = g_cond_new ();
 289
 290       while (g_cond_timed_wait (cond, g_static_mutex_get_mutex (&mutex),
 291                                 &end_time))
 292         /* do nothing */;
 293
 294       g_static_mutex_unlock (&mutex);
 295     }
 296   else
 297     {
 298       struct timeval tv;
 299       tv.tv_sec = microseconds / G_USEC_PER_SEC;
 300       tv.tv_usec = microseconds % G_USEC_PER_SEC;
 301       select(0, NULL, NULL, NULL, &tv);
 302     }
 303 #  endif /* !HAVE_NSLEEP */
 304 # endif /* !HAVE_NANOSLEEP */
 305 #endif /* !G_OS_WIN32 */
 306 }
 307
 308 /**
 309  * g_time_val_add:
 310  * @time_: a #GTimeVal
 311  * @microseconds: number of microseconds to add to @time
 312  *
 313  * Adds the given number of microseconds to @time_. @microseconds can
 314  * also be negative to decrease the value of @time_.
 315  **/
 316 void
 317 g_time_val_add (GTimeVal *time_, glong microseconds)
 318 {
 319   g_return_if_fail (time_->tv_usec >= 0 && time_->tv_usec < G_USEC_PER_SEC);
 320
 321   if (microseconds >= 0)
 322     {
 323       time_->tv_usec += microseconds % G_USEC_PER_SEC;
 324       time_->tv_sec += microseconds / G_USEC_PER_SEC;
 325       if (time_->tv_usec >= G_USEC_PER_SEC)
 326        {
 327          time_->tv_usec -= G_USEC_PER_SEC;
 328          time_->tv_sec++;
 329        }
 330     }
 331   else
 332     {
 333       microseconds *= -1;
 334       time_->tv_usec -= microseconds % G_USEC_PER_SEC;
 335       time_->tv_sec -= microseconds / G_USEC_PER_SEC;
 336       if (time_->tv_usec < 0)
 337        {
 338          time_->tv_usec += G_USEC_PER_SEC;
 339          time_->tv_sec--;
 340        }
 341     }
 342 }
 343
 344 /* converts a broken down date representation, relative to UTC, to
 345  * a timestamp; it uses timegm() if it's available.
 346  */
 347 static time_t
 348 mktime_utc (struct tm *tm)
 349 {
 350   time_t retval;
 351
 352 #ifndef HAVE_TIMEGM
 353   static const gint days_before[] =
 354   {
 355     0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
 356   };
 357 #endif
 358
 359 #ifndef HAVE_TIMEGM
 360   if (tm->tm_mon < 0 || tm->tm_mon > 11)
 361     return (time_t) -1;
 362
 363   retval = (tm->tm_year - 70) * 365;
 364   retval += (tm->tm_year - 68) / 4;
 365   retval += days_before[tm->tm_mon] + tm->tm_mday - 1;
 366
 367   if (tm->tm_year % 4 == 0 && tm->tm_mon < 2)
 368     retval -= 1;
 369
 370   retval = ((((retval * 24) + tm->tm_hour) * 60) + tm->tm_min) * 60 + tm->tm_sec;
 371 #else
 372   retval = timegm (tm);
 373 #endif /* !HAVE_TIMEGM */
 374
 375   return retval;
 376 }
 377
 378 /**
 379  * g_time_val_from_iso8601:
 380  * @iso_date: an ISO 8601 encoded date string
 381  * @time_: a #GTimeVal
 382  *
 383  * Converts a string containing an ISO 8601 encoded date and time
 384  * to a #GTimeVal and puts it into @time_.
 385  *
 386  * Return value: %TRUE if the conversion was successful.
 387  *
 388  * Since: 2.12
 389  */
 390 gboolean
 391 g_time_val_from_iso8601 (const gchar *iso_date,
 392                          GTimeVal    *time_)
 393 {
 394   struct tm tm = {0};
 395   long val;
 396
 397   g_return_val_if_fail (iso_date != NULL, FALSE);
 398   g_return_val_if_fail (time_ != NULL, FALSE);
 399
 400   /* Ensure that the first character is a digit,
 401    * the first digit of the date, otherwise we don't
 402    * have an ISO 8601 date */
 403   while (g_ascii_isspace (*iso_date))
 404     iso_date++;
 405
 406   if (*iso_date == '\0')
 407     return FALSE;
 408
 409   if (!g_ascii_isdigit (*iso_date) && *iso_date != '-' && *iso_date != '+')
 410     return FALSE;
 411
 412   val = strtoul (iso_date, (char **)&iso_date, 10);
 413   if (*iso_date == '-')
 414     {
 415       /* YYYY-MM-DD */
 416       tm.tm_year = val - 1900;
 417       iso_date++;
 418       tm.tm_mon = strtoul (iso_date, (char **)&iso_date, 10) - 1;
 419
 420       if (*iso_date++ != '-')
 421         return FALSE;
 422
 423       tm.tm_mday = strtoul (iso_date, (char **)&iso_date, 10);
 424     }
 425   else
 426     {
 427       /* YYYYMMDD */
 428       tm.tm_mday = val % 100;
 429       tm.tm_mon = (val % 10000) / 100 - 1;
 430       tm.tm_year = val / 10000 - 1900;
 431     }
 432
 433   if (*iso_date++ != 'T')
 434     return FALSE;
 435
 436   val = strtoul (iso_date, (char **)&iso_date, 10);
 437   if (*iso_date == ':')
 438     {
 439       /* hh:mm:ss */
 440       tm.tm_hour = val;
 441       iso_date++;
 442       tm.tm_min = strtoul (iso_date, (char **)&iso_date, 10);
 443
 444       if (*iso_date++ != ':')
 445         return FALSE;
 446
 447       tm.tm_sec = strtoul (iso_date, (char **)&iso_date, 10);
 448     }
 449   else
 450     {
 451       /* hhmmss */
 452       tm.tm_sec = val % 100;
 453       tm.tm_min = (val % 10000) / 100;
 454       tm.tm_hour = val / 10000;
 455     }
 456
 457   time_->tv_usec = 0;
 458
 459   if (*iso_date == ',' || *iso_date == '.')
 460     {
 461       glong mul = 100000;
 462
 463       while (g_ascii_isdigit (*++iso_date))
 464         {
 465           time_->tv_usec += (*iso_date - '0') * mul;
 466           mul /= 10;
 467         }
 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         val = 60 * val + strtoul (iso_date + 1, (char **)&iso_date, 10);
 484       else
 485         val = 60 * (val / 100) + (val % 100);
 486
 487       time_->tv_sec = mktime_utc (&tm) + (time_t) (60 * val * sign);
 488     }
 489   else
 490     {
 491       /* No "Z" or offset, so local time */
 492       tm.tm_isdst = -1; /* locale selects DST */
 493       time_->tv_sec = mktime (&tm);
 494     }
 495
 496   while (g_ascii_isspace (*iso_date))
 497     iso_date++;
 498
 499   return *iso_date == '\0';
 500 }
 501
 502 /**
 503  * g_time_val_to_iso8601:
 504  * @time_: a #GTimeVal
 505  *
 506  * Converts @time_ into an ISO 8601 encoded string, relative to the
 507  * Coordinated Universal Time (UTC).
 508  *
 509  * Return value: a newly allocated string containing an ISO 8601 date
 510  *
 511  * Since: 2.12
 512  */
 513 gchar *
 514 g_time_val_to_iso8601 (GTimeVal *time_)
 515 {
 516   gchar *retval;
 517   struct tm *tm;
 518 #ifdef HAVE_GMTIME_R
 519   struct tm tm_;
 520 #endif
 521   time_t secs;
 522
 523   g_return_val_if_fail (time_->tv_usec >= 0 && time_->tv_usec < G_USEC_PER_SEC, NULL);
 524
 525  secs = time_->tv_sec;
 526 #ifdef _WIN32
 527  tm = gmtime (&secs);
 528 #else
 529 #ifdef HAVE_GMTIME_R
 530   tm = gmtime_r (&secs, &tm_);
 531 #else
 532   tm = gmtime (&secs);
 533 #endif
 534 #endif
 535
 536   if (time_->tv_usec != 0)
 537     {
 538       /* ISO 8601 date and time format, with fractionary seconds:
 539        *   YYYY-MM-DDTHH:MM:SS.MMMMMMZ
 540        */
 541       retval = g_strdup_printf ("%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ",
 542                                 tm->tm_year + 1900,
 543                                 tm->tm_mon + 1,
 544                                 tm->tm_mday,
 545                                 tm->tm_hour,
 546                                 tm->tm_min,
 547                                 tm->tm_sec,
 548                                 time_->tv_usec);
 549     }
 550   else
 551     {
 552       /* ISO 8601 date and time format:
 553        *   YYYY-MM-DDTHH:MM:SSZ
 554        */
 555       retval = g_strdup_printf ("%4d-%02d-%02dT%02d:%02d:%02dZ",
 556                                 tm->tm_year + 1900,
 557                                 tm->tm_mon + 1,
 558                                 tm->tm_mday,
 559                                 tm->tm_hour,
 560                                 tm->tm_min,
 561                                 tm->tm_sec);
 562     }
 563
 564   return retval;
 565 }
 566
 567 #define __G_TIMER_C__
 568 #include "galiasdef.c"