gio/gfilemonitor.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Alexander Larsson <alexl@redhat.com>
  21  */
  22
  23 #include "config.h"
  24 #include <string.h>
  25
  26 #include "gfilemonitor.h"
  27 #include "gioenumtypes.h"
  28 #include "gfile.h"
  29 #include "gvfs.h"
  30 #include "glibintl.h"
  31
  32
  33 struct _FileChange;
  34 typedef struct _FileChange FileChange;
  35 static void file_change_free (FileChange *change);
  36
  37 /**
  38  * SECTION:gfilemonitor
  39  * @short_description: File Monitor
  40  * @include: gio/gio.h
  41  *
  42  * Monitors a file or directory for changes.
  43  *
  44  * To obtain a #GFileMonitor for a file or directory, use
  45  * g_file_monitor(), g_file_monitor_file(), or
  46  * g_file_monitor_directory().
  47  *
  48  * To get informed about changes to the file or directory you are
  49  * monitoring, connect to the #GFileMonitor::changed signal. The
  50  * signal will be emitted in the <link
  51  * linkend="g-main-context-push-thread-default">thread-default main
  52  * context</link> of the thread that the monitor was created in
  53  * (though if the global default main context is blocked, this may
  54  * cause notifications to be blocked even if the thread-default
  55  * context is still running).
  56  **/
  57
  58 G_LOCK_DEFINE_STATIC(cancelled);
  59
  60 enum {
  61   CHANGED,
  62   LAST_SIGNAL
  63 };
  64
  65 /* work around a limitation of the aliasing foo */
  66 #undef g_file_monitor
  67
  68 G_DEFINE_ABSTRACT_TYPE (GFileMonitor, g_file_monitor, G_TYPE_OBJECT);
  69
  70 typedef struct {
  71   GFile *file;
  72   guint32 last_sent_change_time; /* 0 == not sent */
  73   guint32 send_delayed_change_at; /* 0 == never */
  74   guint32 send_virtual_changes_done_at; /* 0 == never */
  75 } RateLimiter;
  76
  77 struct _GFileMonitorPrivate {
  78   gboolean cancelled;
  79   int rate_limit_msec;
  80
  81   /* Rate limiting change events */
  82   GHashTable *rate_limiter;
  83
  84   GMutex mutex;
  85   GSource *pending_file_change_source;
  86   GSList *pending_file_changes; /* FileChange */
  87
  88   GSource *timeout;
  89   guint32 timeout_fires_at;
  90
  91   GMainContext *context;
  92 };
  93
  94 enum {
  95   PROP_0,
  96   PROP_RATE_LIMIT,
  97   PROP_CANCELLED
  98 };
  99
 100 static void
 101 g_file_monitor_set_property (GObject      *object,
 102                              guint         prop_id,
 103                              const GValue *value,
 104                              GParamSpec   *pspec)
 105 {
 106   GFileMonitor *monitor;
 107
 108   monitor = G_FILE_MONITOR (object);
 109
 110   switch (prop_id)
 111     {
 112     case PROP_RATE_LIMIT:
 113       g_file_monitor_set_rate_limit (monitor, g_value_get_int (value));
 114       break;
 115
 116     default:
 117       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 118       break;
 119     }
 120 }
 121
 122 static void
 123 g_file_monitor_get_property (GObject    *object,
 124                              guint       prop_id,
 125                              GValue     *value,
 126                              GParamSpec *pspec)
 127 {
 128   GFileMonitor *monitor;
 129   GFileMonitorPrivate *priv;
 130
 131   monitor = G_FILE_MONITOR (object);
 132   priv = monitor->priv;
 133
 134   switch (prop_id)
 135     {
 136     case PROP_RATE_LIMIT:
 137       g_value_set_int (value, priv->rate_limit_msec);
 138       break;
 139
 140     case PROP_CANCELLED:
 141       G_LOCK (cancelled);
 142       g_value_set_boolean (value, priv->cancelled);
 143       G_UNLOCK (cancelled);
 144       break;
 145
 146     default:
 147       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 148       break;
 149     }
 150 }
 151
 152 #define DEFAULT_RATE_LIMIT_MSECS 800
 153 #define DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS 2
 154
 155 static guint signals[LAST_SIGNAL] = { 0 };
 156
 157 static void
 158 rate_limiter_free (RateLimiter *limiter)
 159 {
 160   g_object_unref (limiter->file);
 161   g_slice_free (RateLimiter, limiter);
 162 }
 163
 164 static void
 165 g_file_monitor_finalize (GObject *object)
 166 {
 167   GFileMonitor *monitor;
 168
 169   monitor = G_FILE_MONITOR (object);
 170
 171   if (monitor->priv->timeout)
 172     {
 173       g_source_destroy (monitor->priv->timeout);
 174       g_source_unref (monitor->priv->timeout);
 175     }
 176
 177   g_hash_table_destroy (monitor->priv->rate_limiter);
 178
 179   g_main_context_unref (monitor->priv->context);
 180   g_mutex_clear (&monitor->priv->mutex);
 181
 182   G_OBJECT_CLASS (g_file_monitor_parent_class)->finalize (object);
 183 }
 184
 185 static void
 186 g_file_monitor_dispose (GObject *object)
 187 {
 188   GFileMonitor *monitor;
 189   GFileMonitorPrivate *priv;
 190
 191   monitor = G_FILE_MONITOR (object);
 192   priv = monitor->priv;
 193
 194   if (priv->pending_file_change_source)
 195     {
 196       g_source_destroy (priv->pending_file_change_source);
 197       g_source_unref (priv->pending_file_change_source);
 198       priv->pending_file_change_source = NULL;
 199     }
 200   g_slist_free_full (priv->pending_file_changes, (GDestroyNotify) file_change_free);
 201   priv->pending_file_changes = NULL;
 202
 203   /* Make sure we cancel on last unref */
 204   g_file_monitor_cancel (monitor);
 205
 206   G_OBJECT_CLASS (g_file_monitor_parent_class)->dispose (object);
 207 }
 208
 209 static void
 210 g_file_monitor_class_init (GFileMonitorClass *klass)
 211 {
 212   GObjectClass *object_class;
 213
 214   g_type_class_add_private (klass, sizeof (GFileMonitorPrivate));
 215
 216   object_class = G_OBJECT_CLASS (klass);
 217   object_class->finalize = g_file_monitor_finalize;
 218   object_class->dispose = g_file_monitor_dispose;
 219   object_class->get_property = g_file_monitor_get_property;
 220   object_class->set_property = g_file_monitor_set_property;
 221
 222   /**
 223    * GFileMonitor::changed:
 224    * @monitor: a #GFileMonitor.
 225    * @file: a #GFile.
 226    * @other_file: (allow-none): a #GFile or #NULL.
 227    * @event_type: a #GFileMonitorEvent.
 228    *
 229    * Emitted when @file has been changed.
 230    *
 231    * If using #G_FILE_MONITOR_SEND_MOVED flag and @event_type is
 232    * #G_FILE_MONITOR_EVENT_MOVED, @file will be set to a #GFile containing the
 233    * old path, and @other_file will be set to a #GFile containing the new path.
 234    *
 235    * In all the other cases, @other_file will be set to #NULL.
 236    **/
 237   signals[CHANGED] =
 238     g_signal_new (I_("changed"),
 239                   G_TYPE_FILE_MONITOR,
 240                   G_SIGNAL_RUN_LAST,
 241                   G_STRUCT_OFFSET (GFileMonitorClass, changed),
 242                   NULL, NULL,
 243                   NULL,
 244                   G_TYPE_NONE, 3,
 245                   G_TYPE_FILE, G_TYPE_FILE, G_TYPE_FILE_MONITOR_EVENT);
 246
 247   g_object_class_install_property (object_class,
 248                                    PROP_RATE_LIMIT,
 249                                    g_param_spec_int ("rate-limit",
 250                                                      P_("Rate limit"),
 251                                                      P_("The limit of the monitor to watch for changes, in milliseconds"),
 252                                                      0, G_MAXINT,
 253                                                      DEFAULT_RATE_LIMIT_MSECS,
 254                                                      G_PARAM_READWRITE|
 255                                                      G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 256
 257   g_object_class_install_property (object_class,
 258                                    PROP_CANCELLED,
 259                                    g_param_spec_boolean ("cancelled",
 260                                                          P_("Cancelled"),
 261                                                          P_("Whether the monitor has been cancelled"),
 262                                                          FALSE,
 263                                                          G_PARAM_READABLE|
 264                                                          G_PARAM_STATIC_NAME|G_PARAM_STATIC_NICK|G_PARAM_STATIC_BLURB));
 265 }
 266
 267 static void
 268 g_file_monitor_init (GFileMonitor *monitor)
 269 {
 270   monitor->priv = G_TYPE_INSTANCE_GET_PRIVATE (monitor,
 271                                                G_TYPE_FILE_MONITOR,
 272                                                GFileMonitorPrivate);
 273   monitor->priv->rate_limit_msec = DEFAULT_RATE_LIMIT_MSECS;
 274   monitor->priv->rate_limiter = g_hash_table_new_full (g_file_hash, (GEqualFunc)g_file_equal,
 275                                                        NULL, (GDestroyNotify) rate_limiter_free);
 276   monitor->priv->context = g_main_context_ref_thread_default ();
 277   g_mutex_init (&monitor->priv->mutex);
 278 }
 279
 280 /**
 281  * g_file_monitor_is_cancelled:
 282  * @monitor: a #GFileMonitor
 283  *
 284  * Returns whether the monitor is canceled.
 285  *
 286  * Returns: %TRUE if monitor is canceled. %FALSE otherwise.
 287  **/
 288 gboolean
 289 g_file_monitor_is_cancelled (GFileMonitor *monitor)
 290 {
 291   gboolean res;
 292
 293   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 294
 295   G_LOCK (cancelled);
 296   res = monitor->priv->cancelled;
 297   G_UNLOCK (cancelled);
 298
 299   return res;
 300 }
 301
 302 /**
 303  * g_file_monitor_cancel:
 304  * @monitor: a #GFileMonitor.
 305  *
 306  * Cancels a file monitor.
 307  *
 308  * Returns: %TRUE if monitor was cancelled.
 309  **/
 310 gboolean
 311 g_file_monitor_cancel (GFileMonitor* monitor)
 312 {
 313   GFileMonitorClass *klass;
 314
 315   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 316
 317   G_LOCK (cancelled);
 318   if (monitor->priv->cancelled)
 319     {
 320       G_UNLOCK (cancelled);
 321       return TRUE;
 322     }
 323
 324   monitor->priv->cancelled = TRUE;
 325   G_UNLOCK (cancelled);
 326
 327   g_object_notify (G_OBJECT (monitor), "cancelled");
 328
 329   klass = G_FILE_MONITOR_GET_CLASS (monitor);
 330   return (* klass->cancel) (monitor);
 331 }
 332
 333 /**
 334  * g_file_monitor_set_rate_limit:
 335  * @monitor: a #GFileMonitor.
 336  * @limit_msecs: a non-negative integer with the limit in milliseconds
 337  *     to poll for changes
 338  *
 339  * Sets the rate limit to which the @monitor will report
 340  * consecutive change events to the same file.
 341  */
 342 void
 343 g_file_monitor_set_rate_limit (GFileMonitor *monitor,
 344                                gint          limit_msecs)
 345 {
 346   GFileMonitorPrivate *priv;
 347
 348   g_return_if_fail (G_IS_FILE_MONITOR (monitor));
 349   g_return_if_fail (limit_msecs >= 0);
 350
 351   priv = monitor->priv;
 352   if (priv->rate_limit_msec != limit_msecs)
 353     {
 354       monitor->priv->rate_limit_msec = limit_msecs;
 355       g_object_notify (G_OBJECT (monitor), "rate-limit");
 356     }
 357 }
 358
 359 struct _FileChange {
 360   GFile             *child;
 361   GFile             *other_file;
 362   GFileMonitorEvent  event_type;
 363 };
 364
 365 static void
 366 file_change_free (FileChange *change)
 367 {
 368   g_object_unref (change->child);
 369   if (change->other_file)
 370     g_object_unref (change->other_file);
 371
 372   g_slice_free (FileChange, change);
 373 }
 374
 375 static gboolean
 376 emit_cb (gpointer data)
 377 {
 378   GFileMonitor *monitor = G_FILE_MONITOR (data);
 379   GSList *pending, *iter;
 380
 381   g_mutex_lock (&monitor->priv->mutex);
 382   pending = g_slist_reverse (monitor->priv->pending_file_changes);
 383   monitor->priv->pending_file_changes = NULL;
 384   if (monitor->priv->pending_file_change_source)
 385     {
 386       g_source_unref (monitor->priv->pending_file_change_source);
 387       monitor->priv->pending_file_change_source = NULL;
 388     }
 389   g_mutex_unlock (&monitor->priv->mutex);
 390
 391   g_object_ref (monitor);
 392   for (iter = pending; iter; iter = iter->next)
 393     {
 394        FileChange *change = iter->data;
 395
 396        g_signal_emit (monitor, signals[CHANGED], 0,
 397                       change->child, change->other_file, change->event_type);
 398        file_change_free (change);
 399     }
 400   g_slist_free (pending);
 401   g_object_unref (monitor);
 402
 403   return FALSE;
 404 }
 405
 406 static void
 407 emit_in_idle (GFileMonitor      *monitor,
 408               GFile             *child,
 409               GFile             *other_file,
 410               GFileMonitorEvent  event_type)
 411 {
 412   GSource *source;
 413   FileChange *change;
 414   GFileMonitorPrivate *priv;
 415
 416   priv = monitor->priv;
 417
 418   change = g_slice_new (FileChange);
 419
 420   change->child = g_object_ref (child);
 421   if (other_file)
 422     change->other_file = g_object_ref (other_file);
 423   else
 424     change->other_file = NULL;
 425   change->event_type = event_type;
 426
 427   g_mutex_lock (&monitor->priv->mutex);
 428   if (!priv->pending_file_change_source)
 429     {
 430       source = g_idle_source_new ();
 431       priv->pending_file_change_source = source;
 432       g_source_set_priority (source, 0);
 433
 434       /* We don't ref monitor here - instead dispose will free any
 435        * pending idles.
 436        */
 437       g_source_set_callback (source, emit_cb, monitor, NULL);
 438       g_source_attach (source, monitor->priv->context);
 439     }
 440   /* We reverse this in the processor */
 441   priv->pending_file_changes = g_slist_prepend (priv->pending_file_changes, change);
 442   g_mutex_unlock (&monitor->priv->mutex);
 443 }
 444
 445 static guint32
 446 get_time_msecs (void)
 447 {
 448   return g_get_monotonic_time () / G_TIME_SPAN_MILLISECOND;
 449 }
 450
 451 static guint32
 452 time_difference (guint32 from, guint32 to)
 453 {
 454   if (from > to)
 455     return 0;
 456   return to - from;
 457 }
 458
 459 /* Change event rate limiting support: */
 460
 461 static RateLimiter *
 462 new_limiter (GFileMonitor *monitor,
 463              GFile             *file)
 464 {
 465   RateLimiter *limiter;
 466
 467   limiter = g_slice_new0 (RateLimiter);
 468   limiter->file = g_object_ref (file);
 469   g_hash_table_insert (monitor->priv->rate_limiter, file, limiter);
 470
 471   return limiter;
 472 }
 473
 474 static void
 475 rate_limiter_send_virtual_changes_done_now (GFileMonitor *monitor,
 476                                             RateLimiter  *limiter)
 477 {
 478   if (limiter->send_virtual_changes_done_at != 0)
 479     {
 480       emit_in_idle (monitor, limiter->file, NULL,
 481                     G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT);
 482       limiter->send_virtual_changes_done_at = 0;
 483     }
 484 }
 485
 486 static void
 487 rate_limiter_send_delayed_change_now (GFileMonitor *monitor,
 488                                       RateLimiter *limiter,
 489                                       guint32 time_now)
 490 {
 491   if (limiter->send_delayed_change_at != 0)
 492     {
 493       emit_in_idle (monitor,
 494                     limiter->file, NULL,
 495                     G_FILE_MONITOR_EVENT_CHANGED);
 496       limiter->send_delayed_change_at = 0;
 497       limiter->last_sent_change_time = time_now;
 498     }
 499 }
 500
 501 typedef struct {
 502   guint32 min_time;
 503   guint32 time_now;
 504   GFileMonitor *monitor;
 505 } ForEachData;
 506
 507 static gboolean
 508 calc_min_time (GFileMonitor *monitor,
 509                RateLimiter *limiter,
 510                guint32 time_now,
 511                guint32 *min_time)
 512 {
 513   gboolean delete_me;
 514   guint32 expire_at;
 515
 516   delete_me = TRUE;
 517
 518   if (limiter->last_sent_change_time != 0)
 519     {
 520       /* Set a timeout at 2*rate limit so that we can clear out the change from the hash eventually */
 521       expire_at = limiter->last_sent_change_time + 2 * monitor->priv->rate_limit_msec;
 522
 523       if (time_difference (time_now, expire_at) > 0)
 524         {
 525           delete_me = FALSE;
 526           *min_time = MIN (*min_time,
 527                            time_difference (time_now, expire_at));
 528         }
 529     }
 530
 531   if (limiter->send_delayed_change_at != 0)
 532     {
 533       delete_me = FALSE;
 534       *min_time = MIN (*min_time,
 535                        time_difference (time_now, limiter->send_delayed_change_at));
 536     }
 537
 538   if (limiter->send_virtual_changes_done_at != 0)
 539     {
 540       delete_me = FALSE;
 541       *min_time = MIN (*min_time,
 542                        time_difference (time_now, limiter->send_virtual_changes_done_at));
 543     }
 544
 545   return delete_me;
 546 }
 547
 548 static gboolean
 549 foreach_rate_limiter_fire (gpointer key,
 550                            gpointer value,
 551                            gpointer user_data)
 552 {
 553   RateLimiter *limiter = value;
 554   ForEachData *data = user_data;
 555
 556   if (limiter->send_delayed_change_at != 0 &&
 557       time_difference (data->time_now, limiter->send_delayed_change_at) == 0)
 558     rate_limiter_send_delayed_change_now (data->monitor, limiter, data->time_now);
 559
 560   if (limiter->send_virtual_changes_done_at != 0 &&
 561       time_difference (data->time_now, limiter->send_virtual_changes_done_at) == 0)
 562     rate_limiter_send_virtual_changes_done_now (data->monitor, limiter);
 563
 564   return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
 565 }
 566
 567 static gboolean
 568 rate_limiter_timeout (gpointer timeout_data)
 569 {
 570   GFileMonitor *monitor = timeout_data;
 571   ForEachData data;
 572   GSource *source;
 573
 574   data.min_time = G_MAXUINT32;
 575   data.monitor = monitor;
 576   data.time_now = get_time_msecs ();
 577   g_hash_table_foreach_remove (monitor->priv->rate_limiter,
 578                                foreach_rate_limiter_fire,
 579                                &data);
 580
 581   /* Remove old timeout */
 582   if (monitor->priv->timeout)
 583     {
 584       g_source_destroy (monitor->priv->timeout);
 585       g_source_unref (monitor->priv->timeout);
 586       monitor->priv->timeout = NULL;
 587       monitor->priv->timeout_fires_at = 0;
 588     }
 589
 590   /* Set up new timeout */
 591   if (data.min_time != G_MAXUINT32)
 592     {
 593       source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
 594       g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
 595       g_source_attach (source, monitor->priv->context);
 596
 597       monitor->priv->timeout = source;
 598       monitor->priv->timeout_fires_at = data.time_now + data.min_time;
 599     }
 600
 601   return FALSE;
 602 }
 603
 604 static gboolean
 605 foreach_rate_limiter_update (gpointer key,
 606                              gpointer value,
 607                              gpointer user_data)
 608 {
 609   RateLimiter *limiter = value;
 610   ForEachData *data = user_data;
 611
 612   return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
 613 }
 614
 615 static void
 616 update_rate_limiter_timeout (GFileMonitor *monitor,
 617                              guint new_time)
 618 {
 619   ForEachData data;
 620   GSource *source;
 621
 622   if (monitor->priv->timeout_fires_at != 0 && new_time != 0 &&
 623       time_difference (new_time, monitor->priv->timeout_fires_at) == 0)
 624     return; /* Nothing to do, we already fire earlier than that */
 625
 626   data.min_time = G_MAXUINT32;
 627   data.monitor = monitor;
 628   data.time_now = get_time_msecs ();
 629   g_hash_table_foreach_remove (monitor->priv->rate_limiter,
 630                                foreach_rate_limiter_update,
 631                                &data);
 632
 633   /* Remove old timeout */
 634   if (monitor->priv->timeout)
 635     {
 636       g_source_destroy (monitor->priv->timeout);
 637       g_source_unref (monitor->priv->timeout);
 638       monitor->priv->timeout_fires_at = 0;
 639       monitor->priv->timeout = NULL;
 640     }
 641
 642   /* Set up new timeout */
 643   if (data.min_time != G_MAXUINT32)
 644     {
 645       source = g_timeout_source_new (data.min_time + 1);  /* + 1 to make sure we've really passed the time */
 646       g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
 647       g_source_attach (source, monitor->priv->context);
 648
 649       monitor->priv->timeout = source;
 650       monitor->priv->timeout_fires_at = data.time_now + data.min_time;
 651     }
 652 }
 653
 654 /**
 655  * g_file_monitor_emit_event:
 656  * @monitor: a #GFileMonitor.
 657  * @child: a #GFile.
 658  * @other_file: a #GFile.
 659  * @event_type: a set of #GFileMonitorEvent flags.
 660  *
 661  * Emits the #GFileMonitor::changed signal if a change
 662  * has taken place. Should be called from file monitor
 663  * implementations only.
 664  *
 665  * The signal will be emitted from an idle handler (in the <link
 666  * linkend="g-main-context-push-thread-default">thread-default main
 667  * context</link>).
 668  **/
 669 void
 670 g_file_monitor_emit_event (GFileMonitor      *monitor,
 671                            GFile             *child,
 672                            GFile             *other_file,
 673                            GFileMonitorEvent  event_type)
 674 {
 675   guint32 time_now, since_last;
 676   gboolean emit_now;
 677   RateLimiter *limiter;
 678
 679   g_return_if_fail (G_IS_FILE_MONITOR (monitor));
 680   g_return_if_fail (G_IS_FILE (child));
 681
 682   limiter = g_hash_table_lookup (monitor->priv->rate_limiter, child);
 683
 684   if (event_type != G_FILE_MONITOR_EVENT_CHANGED)
 685     {
 686       if (limiter)
 687         {
 688           rate_limiter_send_delayed_change_now (monitor, limiter, get_time_msecs ());
 689           if (event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT)
 690             limiter->send_virtual_changes_done_at = 0;
 691           else
 692             rate_limiter_send_virtual_changes_done_now (monitor, limiter);
 693           update_rate_limiter_timeout (monitor, 0);
 694         }
 695       emit_in_idle (monitor, child, other_file, event_type);
 696     }
 697   else
 698     {
 699       /* Changed event, rate limit */
 700       time_now = get_time_msecs ();
 701       emit_now = TRUE;
 702
 703       if (limiter)
 704         {
 705           since_last = time_difference (limiter->last_sent_change_time, time_now);
 706           if (since_last < monitor->priv->rate_limit_msec)
 707             {
 708               /* We ignore this change, but arm a timer so that we can fire it later if we
 709                  don't get any other events (that kill this timeout) */
 710               emit_now = FALSE;
 711               if (limiter->send_delayed_change_at == 0)
 712                 {
 713                   limiter->send_delayed_change_at = time_now + monitor->priv->rate_limit_msec;
 714                   update_rate_limiter_timeout (monitor, limiter->send_delayed_change_at);
 715                 }
 716             }
 717         }
 718
 719       if (limiter == NULL)
 720         limiter = new_limiter (monitor, child);
 721
 722       if (emit_now)
 723         {
 724           emit_in_idle (monitor, child, other_file, event_type);
 725
 726           limiter->last_sent_change_time = time_now;
 727           limiter->send_delayed_change_at = 0;
 728           /* Set a timeout of 2*rate limit so that we can clear out the change from the hash eventually */
 729           update_rate_limiter_timeout (monitor, time_now + 2 * monitor->priv->rate_limit_msec);
 730         }
 731
 732       /* Schedule a virtual change done. This is removed if we get a real one, and
 733          postponed if we get more change events. */
 734
 735       limiter->send_virtual_changes_done_at = time_now + DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS * 1000;
 736       update_rate_limiter_timeout (monitor, limiter->send_virtual_changes_done_at);
 737     }
 738 }