Fix crash when calling g_dbus_remove_watch from watch callback

[framework/connectivity/connman.git] / gdbus / watch.c

diff --git a/gdbus/watch.c b/gdbus/watch.c
index ec3be64..c7a4e69 100644 (file)
--- a/gdbus/watch.c
+++ b/gdbus/watch.c
@@ -2,7 +2,7 @@
  *
  *  D-Bus helper library
  *
- *  Copyright (C) 2004-2008  Marcel Holtmann <marcel@holtmann.org>
+ *  Copyright (C) 2004-2009  Marcel Holtmann <marcel@holtmann.org>
  *
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -37,6 +37,9 @@
 #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;
 
@@ -51,6 +54,8 @@ struct name_data {
        DBusConnection *connection;
        char *name;
        GSList *callbacks;
+       GSList *processed;
+       gboolean lock;
 };
 
 static struct name_data *name_data_find(DBusConnection *connection,
@@ -62,13 +67,11 @@ static struct name_data *name_data_find(DBusConnection *connection,
                        current != NULL; current = current->next) {
                struct name_data *data = current->data;
 
-               if (name == NULL && data->name == NULL) {
-                       if (connection == data->connection)
-                               return data;
-               } else {
-                       if (strcmp(name, data->name) == 0)
-                               return data;
-               }
+               if (connection != data->connection)
+                       continue;
+
+               if (name == NULL || g_str_equal(name, data->name))
+                       return data;
        }
 
        return NULL;
@@ -145,7 +148,11 @@ static int name_data_add(DBusConnection *connection, const char *name,
        name_listeners = g_slist_append(name_listeners, data);
 
 done:
-       data->callbacks = g_slist_append(data->callbacks, cb);
+       if (data->lock)
+               data->processed = g_slist_append(data->processed, cb);
+       else
+               data->callbacks = g_slist_append(data->callbacks, cb);
+
        return first;
 }
 
@@ -165,10 +172,18 @@ static void name_data_remove(DBusConnection *connection,
                g_free(cb);
        }
 
-       if (!data->callbacks) {
-               name_listeners = g_slist_remove(name_listeners, data);
-               name_data_free(data);
-       }
+       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)
@@ -220,10 +235,9 @@ static gboolean remove_match(DBusConnection *connection, const char *name)
 static DBusHandlerResult name_exit_filter(DBusConnection *connection,
                                        DBusMessage *message, void *user_data)
 {
-       GSList *l;
        struct name_data *data;
+       struct name_callback *cb;
        char *name, *old, *new;
-       int keep = 0;
 
        if (!dbus_message_is_signal(message, DBUS_INTERFACE_DBUS,
                                                        "NameOwnerChanged"))
@@ -244,8 +258,11 @@ static DBusHandlerResult name_exit_filter(DBusConnection *connection,
                return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
        }
 
-       for (l = data->callbacks; l != NULL; l = l->next) {
-               struct name_callback *cb = l->data;
+       data->lock = TRUE;
+
+       while (data->callbacks) {
+               cb = data->callbacks->data;
+
                if (*new == '\0') {
                        if (cb->disc_func)
                                cb->disc_func(connection, cb->user_data);
@@ -253,16 +270,38 @@ static DBusHandlerResult name_exit_filter(DBusConnection *connection,
                        if (cb->conn_func)
                                cb->conn_func(connection, cb->user_data);
                }
-               if (cb->conn_func && cb->disc_func)
-                       keep = 1;
+
+               /* 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);
        }
 
-       if (keep)
+       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;
@@ -275,7 +314,7 @@ guint g_dbus_add_service_watch(DBusConnection *connection, const char *name,
 {
        int first;
 
-       if (!listener_id) {
+       if (!name_data_find(connection, NULL)) {
                if (!dbus_connection_add_filter(connection,
                                        name_exit_filter, NULL, NULL)) {
                        error("dbus_connection_add_filter() failed");
@@ -334,16 +373,23 @@ gboolean g_dbus_remove_watch(DBusConnection *connection, guint id)
                        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 */
-       if (data->callbacks)
+       /* 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) {
@@ -354,6 +400,12 @@ remove:
        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;
 }
 
@@ -361,13 +413,10 @@ void g_dbus_remove_all_watches(DBusConnection *connection)
 {
        struct name_data *data;
 
-       data = name_data_find(connection, NULL);
-       if (!data) {
-               error("name_listener_indicate_disconnect: no listener found");
-               return;
+       while ((data = name_data_find(connection, NULL))) {
+               name_listeners = g_slist_remove(name_listeners, data);
+               name_data_call_and_free(data);
        }
 
-       debug("name_listener_indicate_disconnect");
-
-       name_data_call_and_free(data);
+       dbus_connection_remove_filter(connection, name_exit_filter, NULL);
 }