Index: bus/dir-watch-dnotify.c
===================================================================
--- bus/dir-watch-dnotify.c.orig	2009-09-08 16:42:18.000000000 +0000
+++ bus/dir-watch-dnotify.c	2011-01-12 19:36:51.293682972 +0000
@@ -1,7 +1,7 @@
 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
 /* dir-watch-dnotify.c  OS specific directory change notification for message bus
  *
- * Copyright (C) 2003 Red Hat, Inc.
+ * Copyright (C) 2003, 2011 Red Hat, Inc.
  *
  * Licensed under the Academic Free License version 2.1
  * 
@@ -32,62 +32,156 @@
 #endif
 
 #include <dbus/dbus-internals.h>
+#include <dbus/dbus-list.h>
 #include "dir-watch.h"
 
 #define MAX_DIRS_TO_WATCH 128
 
 /* use a static array to avoid handling OOM */
 static int fds[MAX_DIRS_TO_WATCH];
+static char *dirs[MAX_DIRS_TO_WATCH];
 static int num_fds = 0;
+static int _dnotify_inited = -1;
 
-void
-bus_watch_directory (const char *dir, BusContext *context)
+static void
+_shutdown_dnotify (void *data)
 {
-  int fd;
+  int i;
+  for (i = 0; i < num_fds; i++)
+    {
+      close (fds[i]);
+      dbus_free (dirs[i]);
+      fds[i] = -1;
+      dirs[i] = NULL;
+    }
+  num_fds = 0;
+}
 
-  _dbus_assert (dir != NULL);
+static int
+_init_dnotify (void)
+{
+  if (_dnotify_inited < 0)
+    {
+      _dbus_register_shutdown_func (_shutdown_dnotify, NULL);
+      _dnotify_inited = 0;
+    }
+  return _dnotify_inited;
+}
+
+/* This interface was introduced to avoid a race condition where
+ * "watched" dirs could momentarily be unwatched */
+void
+bus_set_watched_dirs (BusContext * context, DBusList ** directories)
+{
+  DBusList *link = _dbus_list_get_first_link (directories);
+  int new_fds[MAX_DIRS_TO_WATCH];
+  char *new_dirs[MAX_DIRS_TO_WATCH];
+  int fd, i, j;
 
-  if (num_fds >= MAX_DIRS_TO_WATCH )
+  if (_init_dnotify ())
     {
-      _dbus_warn ("Cannot watch config directory '%s'. Already watching %d directories\n", dir, MAX_DIRS_TO_WATCH);
+      _dbus_warn ("Cannot init dnotify\n");
       goto out;
     }
 
-  fd = open (dir, O_RDONLY);
-  if (fd < 0)
+  for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
     {
-      _dbus_warn ("Cannot open directory '%s'; error '%s'\n", dir, _dbus_strerror (errno));
-      goto out;
+      new_fds[i] = -1;
+      new_dirs[i] = NULL;
     }
+  i = 0;
 
-  if (fcntl (fd, F_NOTIFY, DN_CREATE|DN_DELETE|DN_RENAME|DN_MODIFY) == -1)
+  while (link != NULL)
     {
-      _dbus_warn ("Cannot setup D_NOTIFY for '%s' error '%s'\n", dir, _dbus_strerror (errno));
-      close (fd);
-      goto out;
+      new_dirs[i++] = (char *) link->data;
+      link = _dbus_list_get_next_link (directories, link);
+    }
+  /* Look for directories in both the old and new sets, if
+   * we find one, move its data into the new set.
+   */
+  for (i = 0; new_dirs[i]; i++)
+    {
+      for (j = 0; j < num_fds; j++)
+	{
+	  if (dirs[j] && strcmp (new_dirs[i], dirs[j]) == 0)
+	    {
+	      new_fds[i] = fds[j];
+	      new_dirs[i] = dirs[j];
+	      fds[j] = -1;
+	      dirs[j] = NULL;
+	      break;
+	    }
+	}
     }
-  
-  fds[num_fds++] = fd;
-  _dbus_verbose ("Added watch on config directory '%s'\n", dir);
 
- out:
-  ;
-}
+  /* Any directories we find in "fds" with a nonzero fd must
+   * not be in the new set, so perform cleanup now.
+   */
+  for (j = 0; j < num_fds; j++)
+    {
+      if (fds[j] != -1)
+	{
+	  close (fds[j]);
+	  dbus_free (dirs[j]);
+	  fds[j] = -1;
+	  dirs[j] = NULL;
+	}
+    }
 
-void 
-bus_drop_all_directory_watches (void)
-{
-  int i;
- 
-  _dbus_verbose ("Dropping all watches on config directories\n");
- 
-  for (i = 0; i < num_fds; i++)
+  for (i = 0; new_dirs[i]; i++)
     {
-      if (close (fds[i]) != 0)
+      if (new_fds[i] == -1)
 	{
-	  _dbus_verbose ("Error closing fd %d for config directory watch\n", fds[i]);
+	  fd = open (new_dirs[i], O_RDONLY);
+	  if (fd < 0)
+	    {
+	      if (errno != ENOENT)
+		{
+		  _dbus_warn ("Cannot open directory '%s'; error '%s'\n",
+			      new_dirs[i], _dbus_strerror (errno));
+		  goto out;
+		}
+	      else
+		{
+		  new_fds[i] = -1;
+		  new_dirs[i] = NULL;
+		  continue;
+		}
+	    }
+
+          _dbus_fd_set_close_on_exec (fd);
+
+	  if (fcntl
+	      (fd, F_NOTIFY,
+	       DN_CREATE | DN_DELETE | DN_RENAME | DN_MODIFY) == -1)
+	    {
+	      _dbus_warn ("Cannot setup D_NOTIFY for '%s' error '%s'\n",
+			  new_dirs[i], _dbus_strerror (errno));
+	      close (fd);
+	      goto out;
+	    }
+
+	  new_fds[i] = fd;
+	  new_dirs[i] = _dbus_strdup (new_dirs[i]);
+	  if (!new_dirs[i])
+	    {
+	      close (fd);
+	      new_fds[i] = -1;
+	    }
+	  else
+	    {
+	      _dbus_verbose ("Added watch on config directory '%s'\n",
+			     new_dirs[i]);
+	    }
 	}
     }
-  
-  num_fds = 0;
+  num_fds = i;
+
+  for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
+    {
+      fds[i] = new_fds[i];
+      dirs[i] = new_dirs[i];
+    }
+
+out:;
 }