Logo Search packages:      
Sourcecode: obexd version File versions  Download package

watch.c

/*
 *
 *  D-Bus helper library
 *
 *  Copyright (C) 2004-2009  Marcel Holtmann <marcel@holtmann.org>
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>

#include <glib.h>
#include <dbus/dbus.h>

#include "gdbus.h"

#define info(fmt...)
#define error(fmt...)
#define debug(fmt...)

static DBusHandlerResult name_exit_filter(DBusConnection *connection,
                              DBusMessage *message, void *user_data);

static guint listener_id = 0;
static GSList *name_listeners = NULL;

struct name_callback {
      GDBusWatchFunction conn_func;
      GDBusWatchFunction disc_func;
      void *user_data;
      guint id;
};

struct name_data {
      DBusConnection *connection;
      char *name;
      GSList *callbacks;
      GSList *processed;
      gboolean lock;
};

static struct name_data *name_data_find(DBusConnection *connection,
                                          const char *name)
{
      GSList *current;

      for (current = name_listeners;
                  current != NULL; current = current->next) {
            struct name_data *data = current->data;

            if (connection != data->connection)
                  continue;

            if (name == NULL || g_str_equal(name, data->name))
                  return data;
      }

      return NULL;
}

static struct name_callback *name_callback_find(GSList *callbacks, guint id)
{
      GSList *current;

      for (current = callbacks; current != NULL; current = current->next) {
            struct name_callback *cb = current->data;
            if (cb->id == id)
                  return cb;
      }

      return NULL;
}

static void name_data_call_and_free(struct name_data *data)
{
      GSList *l;

      for (l = data->callbacks; l != NULL; l = l->next) {
            struct name_callback *cb = l->data;
            if (cb->disc_func)
                  cb->disc_func(data->connection, cb->user_data);
            g_free(cb);
      }

      g_slist_free(data->callbacks);
      g_free(data->name);
      g_free(data);
}

static void name_data_free(struct name_data *data)
{
      GSList *l;

      for (l = data->callbacks; l != NULL; l = l->next)
            g_free(l->data);

      g_slist_free(data->callbacks);
      g_free(data->name);
      g_free(data);
}

static int name_data_add(DBusConnection *connection, const char *name,
                                    GDBusWatchFunction connect,
                                    GDBusWatchFunction disconnect,
                                    void *user_data, guint id)
{
      int first = 1;
      struct name_data *data = NULL;
      struct name_callback *cb = NULL;

      cb = g_new(struct name_callback, 1);

      cb->conn_func = connect;
      cb->disc_func = disconnect;
      cb->user_data = user_data;
      cb->id = id;

      data = name_data_find(connection, name);
      if (data) {
            first = 0;
            goto done;
      }

      data = g_new0(struct name_data, 1);

      data->connection = connection;
      data->name = g_strdup(name);

      name_listeners = g_slist_append(name_listeners, data);

done:
      if (data->lock)
            data->processed = g_slist_append(data->processed, cb);
      else
            data->callbacks = g_slist_append(data->callbacks, cb);

      return first;
}

static void name_data_remove(DBusConnection *connection,
                              const char *name, guint id)
{
      struct name_data *data;
      struct name_callback *cb = NULL;

      data = name_data_find(connection, name);
      if (!data)
            return;

      cb = name_callback_find(data->callbacks, id);
      if (cb) {
            data->callbacks = g_slist_remove(data->callbacks, cb);
            g_free(cb);
      }

      if (data->callbacks)
            return;

      name_listeners = g_slist_remove(name_listeners, data);
      name_data_free(data);

      /* Remove filter if there are no listeners left for the connection */
      data = name_data_find(connection, NULL);
      if (!data)
            dbus_connection_remove_filter(connection,
                                    name_exit_filter,
                                    NULL);
}

static gboolean add_match(DBusConnection *connection, const char *name)
{
      DBusError err;
      char match_string[128];

      snprintf(match_string, sizeof(match_string),
                  "interface=%s,member=NameOwnerChanged,arg0=%s",
                  DBUS_INTERFACE_DBUS, name);

      dbus_error_init(&err);

      dbus_bus_add_match(connection, match_string, &err);

      if (dbus_error_is_set(&err)) {
            error("Adding match rule \"%s\" failed: %s", match_string,
                        err.message);
            dbus_error_free(&err);
            return FALSE;
      }

      return TRUE;
}

static gboolean remove_match(DBusConnection *connection, const char *name)
{
      DBusError err;
      char match_string[128];

      snprintf(match_string, sizeof(match_string),
                  "interface=%s,member=NameOwnerChanged,arg0=%s",
                  DBUS_INTERFACE_DBUS, name);

      dbus_error_init(&err);

      dbus_bus_remove_match(connection, match_string, &err);

      if (dbus_error_is_set(&err)) {
            error("Removing owner match rule for %s failed: %s",
                        name, err.message);
            dbus_error_free(&err);
            return FALSE;
      }

      return TRUE;
}

static DBusHandlerResult name_exit_filter(DBusConnection *connection,
                              DBusMessage *message, void *user_data)
{
      struct name_data *data;
      struct name_callback *cb;
      char *name, *old, *new;

      if (!dbus_message_is_signal(message, DBUS_INTERFACE_DBUS,
                                          "NameOwnerChanged"))
            return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

      if (!dbus_message_get_args(message, NULL,
                        DBUS_TYPE_STRING, &name,
                        DBUS_TYPE_STRING, &old,
                        DBUS_TYPE_STRING, &new,
                        DBUS_TYPE_INVALID)) {
            error("Invalid arguments for NameOwnerChanged signal");
            return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
      }

      data = name_data_find(connection, name);
      if (!data) {
            error("Got NameOwnerChanged signal for %s which has no listeners", name);
            return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
      }

      data->lock = TRUE;

      while (data->callbacks) {
            cb = data->callbacks->data;

            if (*new == '\0') {
                  if (cb->disc_func)
                        cb->disc_func(connection, cb->user_data);
            } else {
                  if (cb->conn_func)
                        cb->conn_func(connection, cb->user_data);
            }

            /* Check if the watch was removed/freed by the callback
             * function */
            if (!g_slist_find(data->callbacks, cb))
                  continue;

            data->callbacks = g_slist_remove(data->callbacks, cb);

            if (!cb->conn_func || !cb->disc_func) {
                  g_free(cb);
                  continue;
            }

            data->processed = g_slist_append(data->processed, cb);
      }

      data->callbacks = data->processed;
      data->processed = NULL;
      data->lock = FALSE;

      if (data->callbacks)
            return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

      name_listeners = g_slist_remove(name_listeners, data);
      name_data_free(data);

      /* Remove filter if there no listener left for the connection */
      data = name_data_find(connection, NULL);
      if (!data)
            dbus_connection_remove_filter(connection, name_exit_filter,
                                    NULL);

      remove_match(connection, name);

      return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}

guint g_dbus_add_service_watch(DBusConnection *connection, const char *name,
                        GDBusWatchFunction connect,
                        GDBusWatchFunction disconnect,
                        void *user_data, GDBusDestroyFunction destroy)
{
      int first;

      if (!name_data_find(connection, NULL)) {
            if (!dbus_connection_add_filter(connection,
                              name_exit_filter, NULL, NULL)) {
                  error("dbus_connection_add_filter() failed");
                  return 0;
            }
      }

      listener_id++;
      first = name_data_add(connection, name, connect, disconnect,
                                    user_data, listener_id);
      /* The filter is already added if this is not the first callback
       * registration for the name */
      if (!first)
            return listener_id;

      if (name) {
            debug("name_listener_add(%s)", name);

            if (!add_match(connection, name)) {
                  name_data_remove(connection, name, listener_id);
                  return 0;
            }
      }

      return listener_id;
}

guint g_dbus_add_disconnect_watch(DBusConnection *connection, const char *name,
                        GDBusWatchFunction func,
                        void *user_data, GDBusDestroyFunction destroy)
{
      return g_dbus_add_service_watch(connection, name, NULL, func,
                                          user_data, destroy);
}

guint g_dbus_add_signal_watch(DBusConnection *connection,
                        const char *rule, GDBusSignalFunction function,
                        void *user_data, GDBusDestroyFunction destroy)
{
      return 0;
}

gboolean g_dbus_remove_watch(DBusConnection *connection, guint id)
{
      struct name_data *data;
      struct name_callback *cb;
      GSList *ldata, *lcb;

      if (id == 0)
            return FALSE;

      for (ldata = name_listeners; ldata; ldata = ldata->next) {
            data = ldata->data;
            for (lcb = data->callbacks; lcb; lcb = lcb->next) {
                  cb = lcb->data;
                  if (cb->id == id)
                        goto remove;
            }
            for (lcb = data->processed; lcb; lcb = lcb->next) {
                  cb = lcb->data;
                  if (cb->id == id)
                        goto remove;
            }
      }

      return FALSE;

remove:
      data->callbacks = g_slist_remove(data->callbacks, cb);
      data->processed = g_slist_remove(data->processed, cb);
      g_free(cb);

      /* Don't remove the filter if other callbacks exist or data is lock
       * processing callbacks */
      if (data->callbacks || data->lock)
            return TRUE;

      if (data->name) {
            if (!remove_match(data->connection, data->name))
                  return FALSE;
      }

      name_listeners = g_slist_remove(name_listeners, data);
      name_data_free(data);

      /* Remove filter if there are no listeners left for the connection */
      data = name_data_find(connection, NULL);
      if (!data)
            dbus_connection_remove_filter(connection, name_exit_filter,
                                    NULL);

      return TRUE;
}

void g_dbus_remove_all_watches(DBusConnection *connection)
{
      struct name_data *data;

      while ((data = name_data_find(connection, NULL))) {
            name_listeners = g_slist_remove(name_listeners, data);
            name_data_call_and_free(data);
      }

      dbus_connection_remove_filter(connection, name_exit_filter, NULL);
}

Generated by  Doxygen 1.6.0   Back to index