| /* cairo - a vector graphics library with display and print output |
| * |
| * Copyright © 2009 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., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, 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 <chris@chris-wilson.co.uk> |
| */ |
| |
| #ifndef CAIRO_FREED_POOL_H |
| #define CAIRO_FREED_POOL_H |
| |
| #include "cairoint.h" |
| #include "cairo-atomic-private.h" |
| |
| CAIRO_BEGIN_DECLS |
| |
| #define DISABLE_FREED_POOLS 0 |
| |
| #if HAS_ATOMIC_OPS && ! DISABLE_FREED_POOLS |
| /* Keep a stash of recently freed clip_paths, since we need to |
| * reallocate them frequently. |
| */ |
| #define MAX_FREED_POOL_SIZE 16 |
| typedef struct { |
| void *pool[MAX_FREED_POOL_SIZE]; |
| int top; |
| } freed_pool_t; |
| |
| static cairo_always_inline void * |
| _atomic_fetch (void **slot) |
| { |
| void *ptr; |
| |
| do { |
| ptr = _cairo_atomic_ptr_get (slot); |
| } while (! _cairo_atomic_ptr_cmpxchg (slot, ptr, NULL)); |
| |
| return ptr; |
| } |
| |
| static cairo_always_inline cairo_bool_t |
| _atomic_store (void **slot, void *ptr) |
| { |
| return _cairo_atomic_ptr_cmpxchg (slot, NULL, ptr); |
| } |
| |
| cairo_private void * |
| _freed_pool_get_search (freed_pool_t *pool); |
| |
| static inline void * |
| _freed_pool_get (freed_pool_t *pool) |
| { |
| void *ptr; |
| int i; |
| |
| i = pool->top - 1; |
| if (i < 0) |
| i = 0; |
| |
| ptr = _atomic_fetch (&pool->pool[i]); |
| if (likely (ptr != NULL)) { |
| pool->top = i; |
| return ptr; |
| } |
| |
| /* either empty or contended */ |
| return _freed_pool_get_search (pool); |
| } |
| |
| cairo_private void |
| _freed_pool_put_search (freed_pool_t *pool, void *ptr); |
| |
| static inline void |
| _freed_pool_put (freed_pool_t *pool, void *ptr) |
| { |
| int i; |
| |
| i = pool->top; |
| if (likely (i < ARRAY_LENGTH (pool->pool) && |
| _atomic_store (&pool->pool[i], ptr))) |
| { |
| pool->top = i + 1; |
| return; |
| } |
| |
| /* either full or contended */ |
| _freed_pool_put_search (pool, ptr); |
| } |
| |
| cairo_private void |
| _freed_pool_reset (freed_pool_t *pool); |
| |
| #define HAS_FREED_POOL 1 |
| |
| #else |
| |
| /* A warning about an unused freed-pool in a build without atomics |
| * enabled usually indicates a missing _freed_pool_reset() in the |
| * static reset function */ |
| |
| typedef int freed_pool_t; |
| |
| #define _freed_pool_get(pool) NULL |
| #define _freed_pool_put(pool, ptr) free(ptr) |
| #define _freed_pool_reset(ptr) |
| |
| #endif |
| |
| CAIRO_END_DECLS |
| |
| #endif /* CAIRO_FREED_POOL_PRIVATE_H */ |