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   GSource *pending_file_change_source;
  85   GSList *pending_file_changes; /* FileChange */
  86
  87   GSource *timeout;
  88   guint32 timeout_fires_at;
  89
  90   GMainContext *context;
  91 };
  92
  93 enum {
  94   PROP_0,
  95   PROP_RATE_LIMIT,
  96   PROP_CANCELLED
  97 };
  98
  99 static void
 100 g_file_monitor_set_property (GObject      *object,
 101                              guint         prop_id,
 102                              const GValue *value,
 103                              GParamSpec   *pspec)
 104 {
 105   GFileMonitor *monitor;
 106
 107   monitor = G_FILE_MONITOR (object);
 108
 109   switch (prop_id)
 110     {
 111     case PROP_RATE_LIMIT:
 112       g_file_monitor_set_rate_limit (monitor, g_value_get_int (value));
 113       break;
 114
 115     default:
 116       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 117       break;
 118     }
 119 }
 120
 121 static void
 122 g_file_monitor_get_property (GObject    *object,
 123                              guint       prop_id,
 124                              GValue     *value,
 125                              GParamSpec *pspec)
 126 {
 127   GFileMonitor *monitor;
 128   GFileMonitorPrivate *priv;
 129
 130   monitor = G_FILE_MONITOR (object);
 131   priv = monitor->priv;
 132
 133   switch (prop_id)
 134     {
 135     case PROP_RATE_LIMIT:
 136       g_value_set_int (value, priv->rate_limit_msec);
 137       break;
 138
 139     case PROP_CANCELLED:
 140       G_LOCK (cancelled);
 141       g_value_set_boolean (value, priv->cancelled);
 142       G_UNLOCK (cancelled);
 143       break;
 144
 145     default:
 146       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 147       break;
 148     }
 149 }
 150
 151 #define DEFAULT_RATE_LIMIT_MSECS 800
 152 #define DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS 2
 153
 154 static guint signals[LAST_SIGNAL] = { 0 };
 155
 156 static void
 157 rate_limiter_free (RateLimiter *limiter)
 158 {
 159   g_object_unref (limiter->file);
 160   g_slice_free (RateLimiter, limiter);
 161 }
 162
 163 static void
 164 g_file_monitor_finalize (GObject *object)
 165 {
 166   GFileMonitor *monitor;
 167
 168   monitor = G_FILE_MONITOR (object);
 169
 170   if (monitor->priv->timeout)
 171     {
 172       g_source_destroy (monitor->priv->timeout);
 173       g_source_unref (monitor->priv->timeout);
 174     }
 175
 176   g_hash_table_destroy (monitor->priv->rate_limiter);
 177
 178   if (monitor->priv->context)
 179     g_main_context_unref (monitor->priv->context);
 180
 181   G_OBJECT_CLASS (g_file_monitor_parent_class)->finalize (object);
 182 }
 183
 184 static void
 185 g_file_monitor_dispose (GObject *object)
 186 {
 187   GFileMonitor *monitor;
 188   GFileMonitorPrivate *priv;
 189
 190   monitor = G_FILE_MONITOR (object);
 191   priv = monitor->priv;
 192
 193   if (priv->pending_file_change_source)
 194     {
 195       g_source_destroy (priv->pending_file_change_source);
 196       g_source_unref (priv->pending_file_change_source);
 197       priv->pending_file_change_source = NULL;
 198     }
 199   g_slist_foreach (priv->pending_file_changes, (GFunc) file_change_free, NULL);
 200   g_slist_free (priv->pending_file_changes);
 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: 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_SEND_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_get_thread_default ();
 277 }
 278
 279 /**
 280  * g_file_monitor_is_cancelled:
 281  * @monitor: a #GFileMonitor
 282  *
 283  * Returns whether the monitor is canceled.
 284  *
 285  * Returns: %TRUE if monitor is canceled. %FALSE otherwise.
 286  **/
 287 gboolean
 288 g_file_monitor_is_cancelled (GFileMonitor *monitor)
 289 {
 290   gboolean res;
 291
 292   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 293
 294   G_LOCK (cancelled);
 295   res = monitor->priv->cancelled;
 296   G_UNLOCK (cancelled);
 297
 298   return res;
 299 }
 300
 301 /**
 302  * g_file_monitor_cancel:
 303  * @monitor: a #GFileMonitor.
 304  *
 305  * Cancels a file monitor.
 306  *
 307  * Returns: %TRUE if monitor was cancelled.
 308  **/
 309 gboolean
 310 g_file_monitor_cancel (GFileMonitor* monitor)
 311 {
 312   GFileMonitorClass *klass;
 313
 314   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 315
 316   G_LOCK (cancelled);
 317   if (monitor->priv->cancelled)
 318     {
 319       G_UNLOCK (cancelled);
 320       return TRUE;
 321     }
 322
 323   monitor->priv->cancelled = TRUE;
 324   G_UNLOCK (cancelled);
 325
 326   g_object_notify (G_OBJECT (monitor), "cancelled");
 327
 328   klass = G_FILE_MONITOR_GET_CLASS (monitor);
 329   return (* klass->cancel) (monitor);
 330 }
 331
 332 /**
 333  * g_file_monitor_set_rate_limit:
 334  * @monitor: a #GFileMonitor.
 335  * @limit_msecs: a non-negative integer with the limit in milliseconds
 336  *     to poll for changes
 337  *
 338  * Sets the rate limit to which the @monitor will report
 339  * consecutive change events to the same file.
 340  */
 341 void
 342 g_file_monitor_set_rate_limit (GFileMonitor *monitor,
 343                                gint          limit_msecs)
 344 {
 345   GFileMonitorPrivate *priv;
 346
 347   g_return_if_fail (G_IS_FILE_MONITOR (monitor));
 348   g_return_if_fail (limit_msecs >= 0);
 349
 350   priv = monitor->priv;
 351   if (priv->rate_limit_msec != limit_msecs)
 352     {
 353       monitor->priv->rate_limit_msec = limit_msecs;
 354       g_object_notify (G_OBJECT (monitor), "rate-limit");
 355     }
 356 }
 357
 358 struct _FileChange {
 359   GFile             *child;
 360   GFile             *other_file;
 361   GFileMonitorEvent  event_type;
 362 };
 363
 364 static void
 365 file_change_free (FileChange *change)
 366 {
 367   g_object_unref (change->child);
 368   if (change->other_file)
 369     g_object_unref (change->other_file);
 370
 371   g_slice_free (FileChange, change);
 372 }
 373
 374 static gboolean
 375 emit_cb (gpointer data)
 376 {
 377   GFileMonitor *monitor = G_FILE_MONITOR (data);
 378   GSList *pending, *iter;
 379
 380   pending = g_slist_reverse (monitor->priv->pending_file_changes);
 381   monitor->priv->pending_file_changes = NULL;
 382   if (monitor->priv->pending_file_change_source)
 383     {
 384       g_source_unref (monitor->priv->pending_file_change_source);
 385       monitor->priv->pending_file_change_source = NULL;
 386     }
 387
 388   g_object_ref (monitor);
 389   for (iter = pending; iter; iter = iter->next)
 390     {
 391        FileChange *change = iter->data;
 392        g_signal_emit (monitor, signals[CHANGED], 0,
 393                       change->child, change->other_file, change->event_type);
 394        file_change_free (change);
 395     }
 396   g_slist_free (pending);
 397   g_object_unref (monitor);
 398
 399   return FALSE;
 400 }
 401
 402 static void
 403 emit_in_idle (GFileMonitor      *monitor,
 404               GFile             *child,
 405               GFile             *other_file,
 406               GFileMonitorEvent  event_type)
 407 {
 408   GSource *source;
 409   FileChange *change;
 410   GFileMonitorPrivate *priv;
 411
 412   priv = monitor->priv;
 413
 414   change = g_slice_new (FileChange);
 415
 416   change->child = g_object_ref (child);
 417   if (other_file)
 418     change->other_file = g_object_ref (other_file);
 419   else
 420     change->other_file = NULL;
 421   change->event_type = event_type;
 422
 423   if (!priv->pending_file_change_source)
 424     {
 425       source = g_idle_source_new ();
 426       priv->pending_file_change_source = source;
 427       g_source_set_priority (source, 0);
 428
 429       /* We don't ref monitor here - instead dispose will free any
 430        * pending idles.
 431        */
 432       g_source_set_callback (source, emit_cb, monitor, NULL);
 433       g_source_attach (source, monitor->priv->context);
 434     }
 435   /* We reverse this in the processor */
 436   priv->pending_file_changes = g_slist_prepend (priv->pending_file_changes, change);
 437 }
 438
 439 static guint32
 440 get_time_msecs (void)
 441 {
 442   return g_get_monotonic_time () / G_TIME_SPAN_MILLISECOND;
 443 }
 444
 445 static guint32
 446 time_difference (guint32 from, guint32 to)
 447 {
 448   if (from > to)
 449     return 0;
 450   return to - from;
 451 }
 452
 453 /* Change event rate limiting support: */
 454
 455 static RateLimiter *
 456 new_limiter (GFileMonitor *monitor,
 457              GFile             *file)
 458 {
 459   RateLimiter *limiter;
 460
 461   limiter = g_slice_new0 (RateLimiter);
 462   limiter->file = g_object_ref (file);
 463   g_hash_table_insert (monitor->priv->rate_limiter, file, limiter);
 464
 465   return limiter;
 466 }
 467
 468 static void
 469 rate_limiter_send_virtual_changes_done_now (GFileMonitor *monitor,
 470                                             RateLimiter  *limiter)
 471 {
 472   if (limiter->send_virtual_changes_done_at != 0)
 473     {
 474       emit_in_idle (monitor, limiter->file, NULL,
 475                     G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT);
 476       limiter->send_virtual_changes_done_at = 0;
 477     }
 478 }
 479
 480 static void
 481 rate_limiter_send_delayed_change_now (GFileMonitor *monitor,
 482                                       RateLimiter *limiter,
 483                                       guint32 time_now)
 484 {
 485   if (limiter->send_delayed_change_at != 0)
 486     {
 487       emit_in_idle (monitor,
 488                     limiter->file, NULL,
 489                     G_FILE_MONITOR_EVENT_CHANGED);
 490       limiter->send_delayed_change_at = 0;
 491       limiter->last_sent_change_time = time_now;
 492     }
 493 }
 494
 495 typedef struct {
 496   guint32 min_time;
 497   guint32 time_now;
 498   GFileMonitor *monitor;
 499 } ForEachData;
 500
 501 static gboolean
 502 calc_min_time (GFileMonitor *monitor,
 503                RateLimiter *limiter,
 504                guint32 time_now,
 505                guint32 *min_time)
 506 {
 507   gboolean delete_me;
 508   guint32 expire_at;
 509
 510   delete_me = TRUE;
 511
 512   if (limiter->last_sent_change_time != 0)
 513     {
 514       /* Set a timeout at 2*rate limit so that we can clear out the change from the hash eventually */
 515       expire_at = limiter->last_sent_change_time + 2 * monitor->priv->rate_limit_msec;
 516
 517       if (time_difference (time_now, expire_at) > 0)
 518         {
 519           delete_me = FALSE;
 520           *min_time = MIN (*min_time,
 521                            time_difference (time_now, expire_at));
 522         }
 523     }
 524
 525   if (limiter->send_delayed_change_at != 0)
 526     {
 527       delete_me = FALSE;
 528       *min_time = MIN (*min_time,
 529                        time_difference (time_now, limiter->send_delayed_change_at));
 530     }
 531
 532   if (limiter->send_virtual_changes_done_at != 0)
 533     {
 534       delete_me = FALSE;
 535       *min_time = MIN (*min_time,
 536                        time_difference (time_now, limiter->send_virtual_changes_done_at));
 537     }
 538
 539   return delete_me;
 540 }
 541
 542 static gboolean
 543 foreach_rate_limiter_fire (gpointer key,
 544                            gpointer value,
 545                            gpointer user_data)
 546 {
 547   RateLimiter *limiter = value;
 548   ForEachData *data = user_data;
 549
 550   if (limiter->send_delayed_change_at != 0 &&
 551       time_difference (data->time_now, limiter->send_delayed_change_at) == 0)
 552     rate_limiter_send_delayed_change_now (data->monitor, limiter, data->time_now);
 553
 554   if (limiter->send_virtual_changes_done_at != 0 &&
 555       time_difference (data->time_now, limiter->send_virtual_changes_done_at) == 0)
 556     rate_limiter_send_virtual_changes_done_now (data->monitor, limiter);
 557
 558   return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
 559 }
 560
 561 static gboolean
 562 rate_limiter_timeout (gpointer timeout_data)
 563 {
 564   GFileMonitor *monitor = timeout_data;
 565   ForEachData data;
 566   GSource *source;
 567
 568   data.min_time = G_MAXUINT32;
 569   data.monitor = monitor;
 570   data.time_now = get_time_msecs ();
 571   g_hash_table_foreach_remove (monitor->priv->rate_limiter,
 572                                foreach_rate_limiter_fire,
 573                                &data);
 574
 575   /* Remove old timeout */
 576   if (monitor->priv->timeout)
 577     {
 578       g_source_destroy (monitor->priv->timeout);
 579       g_source_unref (monitor->priv->timeout);
 580       monitor->priv->timeout = NULL;
 581       monitor->priv->timeout_fires_at = 0;
 582     }
 583
 584   /* Set up new timeout */
 585   if (data.min_time != G_MAXUINT32)
 586     {
 587       source = g_timeout_source_new (data.min_time + 1); /* + 1 to make sure we've really passed the time */
 588       g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
 589       g_source_attach (source, monitor->priv->context);
 590
 591       monitor->priv->timeout = source;
 592       monitor->priv->timeout_fires_at = data.time_now + data.min_time;
 593     }
 594
 595   return FALSE;
 596 }
 597
 598 static gboolean
 599 foreach_rate_limiter_update (gpointer key,
 600                              gpointer value,
 601                              gpointer user_data)
 602 {
 603   RateLimiter *limiter = value;
 604   ForEachData *data = user_data;
 605
 606   return calc_min_time (data->monitor, limiter, data->time_now, &data->min_time);
 607 }
 608
 609 static void
 610 update_rate_limiter_timeout (GFileMonitor *monitor,
 611                              guint new_time)
 612 {
 613   ForEachData data;
 614   GSource *source;
 615
 616   if (monitor->priv->timeout_fires_at != 0 && new_time != 0 &&
 617       time_difference (new_time, monitor->priv->timeout_fires_at) == 0)
 618     return; /* Nothing to do, we already fire earlier than that */
 619
 620   data.min_time = G_MAXUINT32;
 621   data.monitor = monitor;
 622   data.time_now = get_time_msecs ();
 623   g_hash_table_foreach_remove (monitor->priv->rate_limiter,
 624                                foreach_rate_limiter_update,
 625                                &data);
 626
 627   /* Remove old timeout */
 628   if (monitor->priv->timeout)
 629     {
 630       g_source_destroy (monitor->priv->timeout);
 631       g_source_unref (monitor->priv->timeout);
 632       monitor->priv->timeout_fires_at = 0;
 633       monitor->priv->timeout = NULL;
 634     }
 635
 636   /* Set up new timeout */
 637   if (data.min_time != G_MAXUINT32)
 638     {
 639       source = g_timeout_source_new (data.min_time + 1);  /* + 1 to make sure we've really passed the time */
 640       g_source_set_callback (source, rate_limiter_timeout, monitor, NULL);
 641       g_source_attach (source, monitor->priv->context);
 642
 643       monitor->priv->timeout = source;
 644       monitor->priv->timeout_fires_at = data.time_now + data.min_time;
 645     }
 646 }
 647
 648 /**
 649  * g_file_monitor_emit_event:
 650  * @monitor: a #GFileMonitor.
 651  * @child: a #GFile.
 652  * @other_file: a #GFile.
 653  * @event_type: a set of #GFileMonitorEvent flags.
 654  *
 655  * Emits the #GFileMonitor::changed signal if a change
 656  * has taken place. Should be called from file monitor
 657  * implementations only.
 658  *
 659  * The signal will be emitted from an idle handler (in the <link
 660  * linkend="g-main-context-push-thread-default">thread-default main
 661  * context</link>).
 662  **/
 663 void
 664 g_file_monitor_emit_event (GFileMonitor      *monitor,
 665                            GFile             *child,
 666                            GFile             *other_file,
 667                            GFileMonitorEvent  event_type)
 668 {
 669   guint32 time_now, since_last;
 670   gboolean emit_now;
 671   RateLimiter *limiter;
 672
 673   g_return_if_fail (G_IS_FILE_MONITOR (monitor));
 674   g_return_if_fail (G_IS_FILE (child));
 675
 676   limiter = g_hash_table_lookup (monitor->priv->rate_limiter, child);
 677
 678   if (event_type != G_FILE_MONITOR_EVENT_CHANGED)
 679     {
 680       if (limiter)
 681         {
 682           rate_limiter_send_delayed_change_now (monitor, limiter, get_time_msecs ());
 683           if (event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT)
 684             limiter->send_virtual_changes_done_at = 0;
 685           else
 686             rate_limiter_send_virtual_changes_done_now (monitor, limiter);
 687           update_rate_limiter_timeout (monitor, 0);
 688         }
 689       emit_in_idle (monitor, child, other_file, event_type);
 690     }
 691   else
 692     {
 693       /* Changed event, rate limit */
 694       time_now = get_time_msecs ();
 695       emit_now = TRUE;
 696
 697       if (limiter)
 698         {
 699           since_last = time_difference (limiter->last_sent_change_time, time_now);
 700           if (since_last < monitor->priv->rate_limit_msec)
 701             {
 702               /* We ignore this change, but arm a timer so that we can fire it later if we
 703                  don't get any other events (that kill this timeout) */
 704               emit_now = FALSE;
 705               if (limiter->send_delayed_change_at == 0)
 706                 {
 707                   limiter->send_delayed_change_at = time_now + monitor->priv->rate_limit_msec;
 708                   update_rate_limiter_timeout (monitor, limiter->send_delayed_change_at);
 709                 }
 710             }
 711         }
 712
 713       if (limiter == NULL)
 714         limiter = new_limiter (monitor, child);
 715
 716       if (emit_now)
 717         {
 718           emit_in_idle (monitor, child, other_file, event_type);
 719
 720           limiter->last_sent_change_time = time_now;
 721           limiter->send_delayed_change_at = 0;
 722           /* Set a timeout of 2*rate limit so that we can clear out the change from the hash eventually */
 723           update_rate_limiter_timeout (monitor, time_now + 2 * monitor->priv->rate_limit_msec);
 724         }
 725
 726       /* Schedule a virtual change done. This is removed if we get a real one, and
 727          postponed if we get more change events. */
 728
 729       limiter->send_virtual_changes_done_at = time_now + DEFAULT_VIRTUAL_CHANGES_DONE_DELAY_SECS * 1000;
 730       update_rate_limiter_timeout (monitor, limiter->send_virtual_changes_done_at);
 731     }
 732 }