From d4451ce306da5e746347985dbdf256fe05b4d9e2 Mon Sep 17 00:00:00 2001
From: Simon McVittie <simon.mcvittie@collabora.co.uk>
Date: Thu, 23 Jun 2011 13:38:04 +0100
Subject: [PATCH 6/8] DBusMessage: always access refcount atomically

---
 dbus/dbus-message.c |   85 ++++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 68 insertions(+), 17 deletions(-)

diff --git a/dbus/dbus-message.c b/dbus/dbus-message.c
index a59ed9b..bd9f9bf 100644
--- a/dbus/dbus-message.c
+++ b/dbus/dbus-message.c
@@ -526,7 +526,15 @@ dbus_message_get_cached (void)
   _dbus_assert (i < MAX_MESSAGE_CACHE_SIZE);
   _dbus_assert (message != NULL);
 
-  _dbus_assert (message->refcount.value == 0);
+#ifndef DBUS_DISABLE_ASSERT
+    {
+      dbus_int32_t old_refcount = _dbus_atomic_inc (&message->refcount);
+
+      _dbus_atomic_dec (&message->refcount);
+      _dbus_assert (old_refcount == 0);
+    }
+#endif
+
   _dbus_assert (message->counters == NULL);
   
   _DBUS_UNLOCK (message_cache);
@@ -586,8 +594,15 @@ dbus_message_cache_or_finalize (DBusMessage *message)
 {
   dbus_bool_t was_cached;
   int i;
-  
-  _dbus_assert (message->refcount.value == 0);
+
+#ifndef DBUS_DISABLE_ASSERT
+    {
+      dbus_int32_t old_refcount = _dbus_atomic_inc (&message->refcount);
+
+      _dbus_atomic_dec (&message->refcount);
+      _dbus_assert (old_refcount == 0);
+    }
+#endif
 
   /* This calls application code and has to be done first thing
    * without holding the lock
@@ -649,8 +664,15 @@ dbus_message_cache_or_finalize (DBusMessage *message)
 #endif
 
  out:
-  _dbus_assert (message->refcount.value == 0);
-  
+#ifndef DBUS_DISABLE_ASSERT
+    {
+      dbus_int32_t old_refcount = _dbus_atomic_inc (&message->refcount);
+
+      _dbus_atomic_dec (&message->refcount);
+      _dbus_assert (old_refcount == 0);
+    }
+#endif
+
   _DBUS_UNLOCK (message_cache);
   
   if (!was_cached)
@@ -1039,7 +1061,14 @@ dbus_message_get_reply_serial  (DBusMessage *message)
 static void
 dbus_message_finalize (DBusMessage *message)
 {
-  _dbus_assert (message->refcount.value == 0);
+#ifndef DBUS_DISABLE_ASSERT
+    {
+      dbus_int32_t old_refcount = _dbus_atomic_inc (&message->refcount);
+
+      _dbus_atomic_dec (&message->refcount);
+      _dbus_assert (old_refcount == 0);
+    }
+#endif
 
   /* This calls application callbacks! */
   _dbus_data_slot_list_free (&message->slot_list);
@@ -1056,8 +1085,15 @@ dbus_message_finalize (DBusMessage *message)
   dbus_free(message->unix_fds);
 #endif
 
-  _dbus_assert (message->refcount.value == 0);
-  
+#ifndef DBUS_DISABLE_ASSERT
+    {
+      dbus_int32_t old_refcount = _dbus_atomic_inc (&message->refcount);
+
+      _dbus_atomic_dec (&message->refcount);
+      _dbus_assert (old_refcount == 0);
+    }
+#endif
+
   dbus_free (message);
 }
 
@@ -1076,7 +1112,7 @@ dbus_message_new_empty_header (void)
   else
     {
       from_cache = FALSE;
-      message = dbus_new (DBusMessage, 1);
+      message = dbus_new0 (DBusMessage, 1);
       if (message == NULL)
         return NULL;
 #ifndef DBUS_DISABLE_CHECKS
@@ -1088,8 +1124,17 @@ dbus_message_new_empty_header (void)
       message->n_unix_fds_allocated = 0;
 #endif
     }
-  
-  message->refcount.value = 1;
+
+#ifdef DBUS_DISABLE_ASSERT
+    _dbus_atomic_inc (&message->refcount);
+#else
+    {
+      dbus_int32_t old_refcount = _dbus_atomic_inc (&message->refcount);
+
+      _dbus_assert (old_refcount == 0);
+    }
+#endif
+
   message->byte_order = DBUS_COMPILER_BYTE_ORDER;
   message->locked = FALSE;
 #ifndef DBUS_DISABLE_CHECKS
@@ -1448,7 +1493,7 @@ dbus_message_copy (const DBusMessage *message)
   if (retval == NULL)
     return NULL;
 
-  retval->refcount.value = 1;
+  _dbus_atomic_inc (&retval->refcount);
   retval->byte_order = message->byte_order;
   retval->locked = FALSE;
 #ifndef DBUS_DISABLE_CHECKS
@@ -1519,14 +1564,20 @@ dbus_message_copy (const DBusMessage *message)
 DBusMessage *
 dbus_message_ref (DBusMessage *message)
 {
-  dbus_int32_t old_refcount;
-
   _dbus_return_val_if_fail (message != NULL, NULL);
   _dbus_return_val_if_fail (message->generation == _dbus_current_generation, NULL);
   _dbus_return_val_if_fail (!message->in_cache, NULL);
-  
-  old_refcount = _dbus_atomic_inc (&message->refcount);
-  _dbus_assert (old_refcount >= 1);
+
+#ifdef DBUS_DISABLE_ASSERT
+  _dbus_atomic_inc (&message->refcount);
+#else
+    {
+      dbus_int32_t old_refcount;
+
+      old_refcount = _dbus_atomic_inc (&message->refcount);
+      _dbus_assert (old_refcount >= 1);
+    }
+#endif
 
   return message;
 }
-- 
1.7.5.4