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 #ifdef HAVE_UNISTD_H
  35 #include <unistd.h>
  36 #endif /* HAVE_UNISTD_H */
  37
  38 #ifndef G_OS_WIN32
  39 #include <sys/time.h>
  40 #include <time.h>
  41 #include <errno.h>
  42 #endif /* G_OS_WIN32 */
  43
  44 #ifdef G_OS_WIN32
  45 #include <windows.h>
  46 #endif /* G_OS_WIN32 */
  47
  48 #include "glib.h"
  49
  50
  51 struct _GTimer
  52 {
  53 #ifdef G_OS_WIN32
  54   DWORD start;
  55   DWORD end;
  56 #else /* !G_OS_WIN32 */
  57   struct timeval start;
  58   struct timeval end;
  59 #endif /* !G_OS_WIN32 */
  60
  61   guint active : 1;
  62 };
  63
  64 #ifdef G_OS_WIN32
  65 #  define GETTIME(v) \
  66      v = GetTickCount ()
  67 #else /* !G_OS_WIN32 */
  68 #  define GETTIME(v) \
  69      gettimeofday (&v, NULL)
  70 #endif /* !G_OS_WIN32 */
  71
  72 GTimer*
  73 g_timer_new (void)
  74 {
  75   GTimer *timer;
  76
  77   timer = g_new (GTimer, 1);
  78   timer->active = TRUE;
  79
  80   GETTIME (timer->start);
  81
  82   return timer;
  83 }
  84
  85 void
  86 g_timer_destroy (GTimer *timer)
  87 {
  88   g_return_if_fail (timer != NULL);
  89
  90   g_free (timer);
  91 }
  92
  93 void
  94 g_timer_start (GTimer *timer)
  95 {
  96   g_return_if_fail (timer != NULL);
  97
  98   timer->active = TRUE;
  99
 100   GETTIME (timer->start);
 101 }
 102
 103 void
 104 g_timer_stop (GTimer *timer)
 105 {
 106   g_return_if_fail (timer != NULL);
 107
 108   timer->active = FALSE;
 109
 110   GETTIME(timer->end);
 111 }
 112
 113 void
 114 g_timer_reset (GTimer *timer)
 115 {
 116   g_return_if_fail (timer != NULL);
 117
 118   GETTIME (timer->start);
 119 }
 120
 121 void
 122 g_timer_continue (GTimer *timer)
 123 {
 124 #ifdef G_OS_WIN32
 125   DWORD elapsed;
 126 #else
 127   struct timeval elapsed;
 128 #endif /* G_OS_WIN32 */
 129
 130   g_return_if_fail (timer != NULL);
 131   g_return_if_fail (timer->active == FALSE);
 132
 133   /* Get elapsed time and reset timer start time
 134    *  to the current time minus the previously
 135    *  elapsed interval.
 136    */
 137
 138 #ifdef G_OS_WIN32
 139
 140   elapsed = timer->end - timer->start;
 141
 142   GETTIME (timer->start);
 143
 144   timer->start -= elapsed;
 145
 146 #else /* !G_OS_WIN32 */
 147
 148   if (timer->start.tv_usec > timer->end.tv_usec)
 149     {
 150       timer->end.tv_usec += G_USEC_PER_SEC;
 151       timer->end.tv_sec--;
 152     }
 153
 154   elapsed.tv_usec = timer->end.tv_usec - timer->start.tv_usec;
 155   elapsed.tv_sec = timer->end.tv_sec - timer->start.tv_sec;
 156
 157   GETTIME (timer->start);
 158
 159   if (timer->start.tv_usec < elapsed.tv_usec)
 160     {
 161       timer->start.tv_usec += G_USEC_PER_SEC;
 162       timer->start.tv_sec--;
 163     }
 164
 165   timer->start.tv_usec -= elapsed.tv_usec;
 166   timer->start.tv_sec -= elapsed.tv_sec;
 167
 168 #endif /* !G_OS_WIN32 */
 169
 170   timer->active = TRUE;
 171 }
 172
 173 gdouble
 174 g_timer_elapsed (GTimer *timer,
 175                  gulong *microseconds)
 176 {
 177   gdouble total;
 178 #ifndef G_OS_WIN32
 179   struct timeval elapsed;
 180 #endif /* G_OS_WIN32 */
 181
 182   g_return_val_if_fail (timer != NULL, 0);
 183
 184 #ifdef G_OS_WIN32
 185   if (timer->active)
 186     timer->end = GetTickCount ();
 187
 188   /* Check for wraparound, which happens every 49.7 days. */
 189   if (timer->end < timer->start)
 190     total = (UINT_MAX - (timer->start - timer->end - 1)) / 1000.0;
 191   else
 192     total = (timer->end - timer->start) / 1000.0;
 193
 194   if (microseconds)
 195     {
 196       if (timer->end < timer->start)
 197         *microseconds =
 198           ((UINT_MAX - (timer->start - timer->end - 1)) % 1000) * 1000;
 199       else
 200         *microseconds =
 201           ((timer->end - timer->start) % 1000) * 1000;
 202     }
 203 #else /* !G_OS_WIN32 */
 204   if (timer->active)
 205     gettimeofday (&timer->end, NULL);
 206
 207   if (timer->start.tv_usec > timer->end.tv_usec)
 208     {
 209       timer->end.tv_usec += G_USEC_PER_SEC;
 210       timer->end.tv_sec--;
 211     }
 212
 213   elapsed.tv_usec = timer->end.tv_usec - timer->start.tv_usec;
 214   elapsed.tv_sec = timer->end.tv_sec - timer->start.tv_sec;
 215
 216   total = elapsed.tv_sec + ((gdouble) elapsed.tv_usec / 1e6);
 217   if (total < 0)
 218     {
 219       total = 0;
 220
 221       if (microseconds)
 222         *microseconds = 0;
 223     }
 224   else if (microseconds)
 225     *microseconds = elapsed.tv_usec;
 226
 227 #endif /* !G_OS_WIN32 */
 228
 229   return total;
 230 }
 231
 232 void
 233 g_usleep (gulong microseconds)
 234 {
 235 #ifdef G_OS_WIN32
 236   Sleep (microseconds / 1000);
 237 #else /* !G_OS_WIN32 */
 238 # ifdef HAVE_NANOSLEEP
 239   struct timespec request, remaining;
 240   request.tv_sec = microseconds / G_USEC_PER_SEC;
 241   request.tv_nsec = 1000 * (microseconds % G_USEC_PER_SEC);
 242   while (nanosleep (&request, &remaining) == EINTR)
 243     request = remaining;
 244 # else /* !HAVE_NANOSLEEP */
 245   if (g_thread_supported ())
 246     {
 247       static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
 248       static GCond* cond = NULL;
 249       GTimeVal end_time;
 250
 251       g_get_current_time (&end_time);
 252       if (microseconds > G_MAXLONG)
 253         {
 254           microseconds -= G_MAXLONG;
 255           g_time_val_add (&end_time, G_MAXLONG);
 256         }
 257       g_time_val_add (&end_time, microseconds);
 258
 259       g_static_mutex_lock (&mutex);
 260
 261       if (!cond)
 262         cond = g_cond_new ();
 263
 264       while (g_cond_timed_wait (cond, g_static_mutex_get_mutex (&mutex),
 265                                 &end_time))
 266         /* do nothing */;
 267
 268       g_static_mutex_unlock (&mutex);
 269     }
 270   else
 271     {
 272       struct timeval tv;
 273       tv.tv_sec = microseconds / G_USEC_PER_SEC;
 274       tv.tv_usec = microseconds % G_USEC_PER_SEC;
 275       select(0, NULL, NULL, NULL, &tv);
 276     }
 277 # endif /* !HAVE_NANOSLEEP */
 278 #endif /* !G_OS_WIN32 */
 279 }
 280
 281 /**
 282  * g_time_val_add:
 283  * @time_: a #GTimeVal
 284  * @microseconds: number of microseconds to add to @time
 285  *
 286  * Adds the given number of microseconds to @time_. @microseconds can
 287  * also be negative to decrease the value of @time_.
 288  **/
 289 void
 290 g_time_val_add (GTimeVal *time_, glong microseconds)
 291 {
 292   g_return_if_fail (time_->tv_usec >= 0 && time_->tv_usec < G_USEC_PER_SEC);
 293
 294   if (microseconds >= 0)
 295     {
 296       time_->tv_usec += microseconds % G_USEC_PER_SEC;
 297       time_->tv_sec += microseconds / G_USEC_PER_SEC;
 298       if (time_->tv_usec >= G_USEC_PER_SEC)
 299        {
 300          time_->tv_usec -= G_USEC_PER_SEC;
 301          time_->tv_sec++;
 302        }
 303     }
 304   else
 305     {
 306       microseconds *= -1;
 307       time_->tv_usec -= microseconds % G_USEC_PER_SEC;
 308       time_->tv_sec -= microseconds / G_USEC_PER_SEC;
 309       if (time_->tv_usec < 0)
 310        {
 311          time_->tv_usec += G_USEC_PER_SEC;
 312          time_->tv_sec--;
 313        }
 314     }
 315 }