From d4e80132af03363a2f861cfd611847ee8758aed9 Mon Sep 17 00:00:00 2001
From: Havoc Pennington <hp@redhat.com>
Date: Mon, 12 May 2003 02:44:45 +0000
Subject: 2003-05-11  Havoc Pennington  <hp@pobox.com>

	* dbus/dbus-marshal.c (_dbus_marshal_validate_arg): fix to avoid
	calling _dbus_marshal_validate_arg() for every byte in a byte
	array, etc.

	* dbus/dbus-message-handler.c: use atomic reference counting to
	reduce number of locks slightly; the global lock in here sucks

	* dbus/dbus-connection.c
	(_dbus_connection_update_dispatch_status_and_unlock): variant of
	update_dispatch_status that can be called with lock held; then use
	in a couple places to reduce locking/unlocking
	(dbus_connection_send): hold the lock over the whole function
	instead of acquiring it twice.

	* dbus/dbus-timeout.c (_dbus_timeout_new): handle OOM

	* bus/connection.c (bus_connections_setup_connection): fix access
	to already-freed memory.

	* dbus/dbus-connection.c: keep a little cache of linked list
	nodes, to avoid using the global linked list alloc lock in the
	normal send-message case. Instead we just use the connection lock
	that we already have to take.

	* dbus/dbus-list.c (_dbus_list_find_last): new function

	* dbus/dbus-sysdeps.c (_dbus_atomic_inc, _dbus_atomic_dec):
	change to use a struct for the atomic type; fix docs,
	they return value before increment, not after increment.

	* dbus/dbus-string.c (_dbus_string_append_4_aligned)
	(_dbus_string_append_8_aligned): new functions to try to
	microoptimize this operation.
	(reallocate_for_length): break this out of set_length(), to
	improve profile info, and also so we can consider inlining the
	set_length() part.

	* dbus/dbus-message.c (dbus_message_new_empty_header): init data
	strings with some preallocation, cuts down on our calls to realloc
	a fair bit. Though if we can get the "move entire string to empty
	string" optimization below to kick in here, it would be better.

	* dbus/dbus-string.c (_dbus_string_move): just call
	_dbus_string_move_len
	(_dbus_string_move_len): add a special case for moving
	an entire string into an empty string; we can just
	swap the string data instead of doing any reallocs.
	(_dbus_string_init_preallocated): new function
---
 dbus/dbus-message-handler.c | 28 ++++++++--------------------
 1 file changed, 8 insertions(+), 20 deletions(-)

(limited to 'dbus/dbus-message-handler.c')

diff --git a/dbus/dbus-message-handler.c b/dbus/dbus-message-handler.c
index a978ba05..f38e5100 100644
--- a/dbus/dbus-message-handler.c
+++ b/dbus/dbus-message-handler.c
@@ -1,7 +1,7 @@
 /* -*- mode: C; c-file-style: "gnu" -*- */
 /* dbus-message-handler.c Sender/receiver of messages.
  *
- * Copyright (C) 2002  Red Hat Inc.
+ * Copyright (C) 2002, 2003 Red Hat Inc.
  *
  * Licensed under the Academic Free License version 1.2
  * 
@@ -47,7 +47,7 @@ _DBUS_DEFINE_GLOBAL_LOCK (message_handler);
  */
 struct DBusMessageHandler
 {
-  int refcount;                                   /**< reference count */
+  DBusAtomic refcount;                            /**< reference count */
 
   DBusHandleMessageFunction function;             /**< handler function */
   void                     *user_data;            /**< user data for function */
@@ -176,7 +176,7 @@ dbus_message_handler_new (DBusHandleMessageFunction function,
   if (handler == NULL)
     return NULL;
   
-  handler->refcount = 1;
+  handler->refcount.value = 1;
   handler->function = function;
   handler->user_data = user_data;
   handler->free_user_data = free_user_data;
@@ -194,12 +194,8 @@ void
 dbus_message_handler_ref (DBusMessageHandler *handler)
 {
   _dbus_return_if_fail (handler != NULL);
-  
-  _DBUS_LOCK (message_handler);
-  _dbus_assert (handler != NULL);
-  
-  handler->refcount += 1;
-  _DBUS_UNLOCK (message_handler);
+
+  _dbus_atomic_inc (&handler->refcount);
 }
 
 /**
@@ -211,21 +207,13 @@ dbus_message_handler_ref (DBusMessageHandler *handler)
 void
 dbus_message_handler_unref (DBusMessageHandler *handler)
 {
-  int refcount;
+  dbus_bool_t last_unref;
 
   _dbus_return_if_fail (handler != NULL);
-  
-  _DBUS_LOCK (message_handler);
-  
-  _dbus_assert (handler != NULL);
-  _dbus_assert (handler->refcount > 0);
 
-  handler->refcount -= 1;
-  refcount = handler->refcount;
-  
-  _DBUS_UNLOCK (message_handler);
+  last_unref = (_dbus_atomic_dec (&handler->refcount) == 1);
   
-  if (refcount == 0)
+  if (last_unref)
     {
       DBusList *link;
       
-- 
cgit