Comment some places where it's OK to unref a message despite holding locks

[platform/upstream/dbus.git] / dbus / dbus-connection.c

diff --git a/dbus/dbus-connection.c b/dbus/dbus-connection.c
index bf927ba..a917f9a 100644 (file)
--- a/dbus/dbus-connection.c
+++ b/dbus/dbus-connection.c
@@ -342,8 +342,14 @@ static dbus_bool_t        _dbus_connection_peek_for_reply_unlocked           (DB
 static DBusMessageFilter *
 _dbus_message_filter_ref (DBusMessageFilter *filter)
 {
-  _dbus_assert (filter->refcount.value > 0);
+#ifdef DBUS_DISABLE_ASSERT
   _dbus_atomic_inc (&filter->refcount);
+#else
+  dbus_int32_t old_value;
+
+  old_value = _dbus_atomic_inc (&filter->refcount);
+  _dbus_assert (old_value > 0);
+#endif
 
   return filter;
 }
@@ -351,9 +357,12 @@ _dbus_message_filter_ref (DBusMessageFilter *filter)
 static void
 _dbus_message_filter_unref (DBusMessageFilter *filter)
 {
-  _dbus_assert (filter->refcount.value > 0);
+  dbus_int32_t old_value;
+
+  old_value = _dbus_atomic_dec (&filter->refcount);
+  _dbus_assert (old_value > 0);
 
-  if (_dbus_atomic_dec (&filter->refcount) == 1)
+  if (old_value == 1)
     {
       if (filter->free_user_data_function)
         (* filter->free_user_data_function) (filter->user_data);
@@ -600,8 +609,8 @@ _dbus_connection_get_message_to_send (DBusConnection *connection)
  * @param message the message that was sent.
  */
 void
-_dbus_connection_message_sent (DBusConnection *connection,
-                               DBusMessage    *message)
+_dbus_connection_message_sent_unlocked (DBusConnection *connection,
+                                        DBusMessage    *message)
 {
   DBusList *link;
 
@@ -1310,8 +1319,9 @@ _dbus_connection_new_for_transport (DBusTransport *transport)
   
   if (_dbus_modify_sigpipe)
     _dbus_disable_sigpipe ();
-  
-  connection->refcount.value = 1;
+
+  /* initialized to 0: use atomic op to avoid mixing atomic and non-atomic */
+  _dbus_atomic_inc (&connection->refcount);
   connection->transport = transport;
   connection->watches = watch_list;
   connection->timeouts = timeout_list;
@@ -2108,23 +2118,15 @@ _dbus_connection_send_and_unlock (DBusConnection *connection,
 void
 _dbus_connection_close_if_only_one_ref (DBusConnection *connection)
 {
-  dbus_int32_t tmp_refcount;
+  dbus_int32_t refcount;
 
   CONNECTION_LOCK (connection);
 
-  /* We increment and then decrement the refcount, because there is no
-   * _dbus_atomic_get (mirroring the fact that there's no InterlockedGet
-   * on Windows). */
-  _dbus_atomic_inc (&connection->refcount);
-  tmp_refcount = _dbus_atomic_dec (&connection->refcount);
-
-  /* The caller should have one ref, and this function temporarily took
-   * one more, which is reflected in this count even though we already
-   * released it (relying on the caller's ref) due to _dbus_atomic_dec
-   * semantics */
-  _dbus_assert (tmp_refcount >= 2);
+  refcount = _dbus_atomic_get (&connection->refcount);
+  /* The caller should have at least one ref */
+  _dbus_assert (refcount >= 1);
 
-  if (tmp_refcount == 2)
+  if (refcount == 1)
     _dbus_connection_close_possibly_shared_and_unlock (connection);
   else
     CONNECTION_UNLOCK (connection);
@@ -2655,9 +2657,9 @@ _dbus_connection_last_unref (DBusConnection *connection)
   DBusList *link;
 
   _dbus_verbose ("Finalizing connection %p\n", connection);
-  
-  _dbus_assert (connection->refcount.value == 0);
-  
+
+  _dbus_assert (_dbus_atomic_get (&connection->refcount) == 0);
+
   /* You have to disconnect the connection before unref:ing it. Otherwise
    * you won't get the disconnected message.
    */
@@ -4141,7 +4143,7 @@ notify_disconnected_unlocked (DBusConnection *connection)
       
       while ((link = _dbus_list_get_last_link (&connection->outgoing_messages)))
         {
-          _dbus_connection_message_sent (connection, link->data);
+          _dbus_connection_message_sent_unlocked (connection, link->data);
         }
     } 
 }
@@ -4699,6 +4701,8 @@ dbus_connection_dispatch (DBusConnection *connection)
 
       if (preallocated == NULL)
         {
+          /* It's OK that this is finalized, because it hasn't been seen by
+           * anything that could attach user callbacks */
           dbus_message_unref (reply);
           result = DBUS_HANDLER_RESULT_NEED_MEMORY;
           _dbus_verbose ("no memory for error send in dispatch\n");
@@ -5420,8 +5424,8 @@ dbus_connection_add_filter (DBusConnection            *connection,
   if (filter == NULL)
     return FALSE;
 
-  filter->refcount.value = 1;
-  
+  _dbus_atomic_inc (&filter->refcount);
+
   CONNECTION_LOCK (connection);
 
   if (!_dbus_list_append (&connection->filter_list,