1/* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
3 *
4 * g_atomic_*: atomic operations.
5 * Copyright (C) 2003 Sebastian Wilhelmi
6 *
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
21 */
22
23/*
24 * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
25 * file for a list of people on the GLib Team.  See the ChangeLog
26 * files for a list of changes.  These files are distributed with
27 * GLib at ftp://ftp.gtk.org/pub/gtk/.
28 */
29
30#if defined(G_DISABLE_SINGLE_INCLUDES) && !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
31#error "Only <glib.h> can be included directly."
32#endif
33
34#ifndef __G_ATOMIC_H__
35#define __G_ATOMIC_H__
36
37#include <glib/gtypes.h>
38
39G_BEGIN_DECLS
40
41gint     g_atomic_int_exchange_and_add         (volatile gint G_GNUC_MAY_ALIAS *atomic,
42						gint      	   val);
43void     g_atomic_int_add                      (volatile gint G_GNUC_MAY_ALIAS *atomic,
44						gint      	   val);
45gboolean g_atomic_int_compare_and_exchange     (volatile gint G_GNUC_MAY_ALIAS *atomic,
46						gint      	   oldval,
47						gint      	   newval);
48gboolean g_atomic_pointer_compare_and_exchange (volatile gpointer G_GNUC_MAY_ALIAS *atomic,
49						gpointer  	   oldval,
50						gpointer  	   newval);
51
52gint     g_atomic_int_get                      (volatile gint G_GNUC_MAY_ALIAS *atomic);
53void     g_atomic_int_set                      (volatile gint G_GNUC_MAY_ALIAS *atomic,
54						gint               newval);
55gpointer g_atomic_pointer_get                  (volatile gpointer G_GNUC_MAY_ALIAS *atomic);
56void     g_atomic_pointer_set                  (volatile gpointer G_GNUC_MAY_ALIAS *atomic,
57						gpointer           newval);
58
59#ifndef G_ATOMIC_OP_MEMORY_BARRIER_NEEDED
60# define g_atomic_int_get(atomic) 		((gint)*(atomic))
61# define g_atomic_int_set(atomic, newval) 	((void) (*(atomic) = (newval)))
62# define g_atomic_pointer_get(atomic) 		((gpointer)*(atomic))
63# define g_atomic_pointer_set(atomic, newval)	((void) (*(atomic) = (newval)))
64#else
65# define g_atomic_int_get(atomic) \
66 ((void) sizeof (gchar [sizeof (*(atomic)) == sizeof (gint) ? 1 : -1]), \
67  (g_atomic_int_get) ((volatile gint G_GNUC_MAY_ALIAS *) (void *) (atomic)))
68# define g_atomic_int_set(atomic, newval) \
69 ((void) sizeof (gchar [sizeof (*(atomic)) == sizeof (gint) ? 1 : -1]), \
70  (g_atomic_int_set) ((volatile gint G_GNUC_MAY_ALIAS *) (void *) (atomic), (newval)))
71# define g_atomic_pointer_get(atomic) \
72 ((void) sizeof (gchar [sizeof (*(atomic)) == sizeof (gpointer) ? 1 : -1]), \
73  (g_atomic_pointer_get) ((volatile gpointer G_GNUC_MAY_ALIAS *) (void *) (atomic)))
74# define g_atomic_pointer_set(atomic, newval) \
75 ((void) sizeof (gchar [sizeof (*(atomic)) == sizeof (gpointer) ? 1 : -1]), \
76  (g_atomic_pointer_set) ((volatile gpointer G_GNUC_MAY_ALIAS *) (void *) (atomic), (newval)))
77#endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
78
79#define g_atomic_int_inc(atomic) (g_atomic_int_add ((atomic), 1))
80#define g_atomic_int_dec_and_test(atomic)				\
81  (g_atomic_int_exchange_and_add ((atomic), -1) == 1)
82
83G_END_DECLS
84
85#endif /* __G_ATOMIC_H__ */
86