From 8b6c871c9084739460f1320cd36560a09477a83e Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 21 Sep 2007 10:45:55 +0100 Subject: [cairo-atomic] Introduce atomic ops. Test for the availability of the Intel __sync_* atomic primitives and use them to define a few operations useful for reference counting - providing a generic interface that may be targeted at more architectures in the future. If no atomic primitives are available, use a mutex based variant. If the contention on that mutex is too high, we can consider using an array of mutexes using the address of the atomic variable as the hash. --- src/cairo-atomic-private.h | 81 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 src/cairo-atomic-private.h (limited to 'src/cairo-atomic-private.h') diff --git a/src/cairo-atomic-private.h b/src/cairo-atomic-private.h new file mode 100644 index 00000000..3577e0d3 --- /dev/null +++ b/src/cairo-atomic-private.h @@ -0,0 +1,81 @@ +/* cairo - a vector graphics library with display and print output + * + * Copyright © 2007 Chris Wilson + * + * This library is free software; you can redistribute it and/or + * modify it either under the terms of the GNU Lesser General Public + * License version 2.1 as published by the Free Software Foundation + * (the "LGPL") or, at your option, under the terms of the Mozilla + * Public License Version 1.1 (the "MPL"). If you do not alter this + * notice, a recipient may use your version of this file under either + * the MPL or the LGPL. + * + * You should have received a copy of the LGPL along with this library + * in the file COPYING-LGPL-2.1; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * You should have received a copy of the MPL along with this library + * in the file COPYING-MPL-1.1 + * + * The contents of this file are subject to the Mozilla Public License + * Version 1.1 (the "License"); you may not use this file except in + * compliance with the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY + * OF ANY KIND, either express or implied. See the LGPL or the MPL for + * the specific language governing rights and limitations. + * + * The Original Code is the cairo graphics library. + * + * The Initial Developer of the Original Code is University of Southern + * California. + * + * Contributor(s): + * Chris Wilson + */ + +#ifndef CAIRO_ATOMIC_PRIVATE_H +#define CAIRO_ATOMIC_PRIVATE_H + +#if HAVE_CONFIG_H +#include "config.h" +#endif + +CAIRO_BEGIN_DECLS + +#define CAIRO_HAS_ATOMIC_OPS 1 + +#if CAIRO_HAS_INTEL_ATOMIC_PRIMITIVES + +typedef int cairo_atomic_int_t; + +# define _cairo_atomic_int_inc(x) ((void) __sync_fetch_and_add(x, 1)) +# define _cairo_atomic_int_dec_and_test(x) (__sync_fetch_and_add(x, -1) == 1) +# define _cairo_atomic_int_get(x) (*x) +# define _cairo_atomic_int_set(x, value) ((*x) = value) + +#else + +# include "cairo-compiler-private.h" + +# undef CAIRO_HAS_ATOMIC_OPS + +typedef int cairo_atomic_int_t; + +cairo_private void +_cairo_atomic_int_inc (int *x); + +cairo_private cairo_bool_t +_cairo_atomic_int_dec_and_test (int *x); + +cairo_private int +_cairo_atomic_int_get (int *x); + +cairo_private void +_cairo_atomic_int_set (int *x, int value); + +#endif + +CAIRO_END_DECLS + +#endif -- cgit v1.2.3