1/* 2 * Copyright (C) 1998-2000 Netscape Communications Corporation. 3 * Copyright (C) 2003-6 Apple Computer 4 * Copyright (C) Research In Motion Limited 2010. All rights reserved. 5 * 6 * Other contributors: 7 * Nick Blievers <nickb@adacel.com.au> 8 * Jeff Hostetler <jeff@nerdone.com> 9 * Tom Rini <trini@kernel.crashing.org> 10 * Raffaele Sena <raff@netwinder.org> 11 * 12 * This library is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU Lesser General Public 14 * License as published by the Free Software Foundation; either 15 * version 2.1 of the License, or (at your option) any later version. 16 * 17 * This library is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 20 * Lesser General Public License for more details. 21 * 22 * You should have received a copy of the GNU Lesser General Public 23 * License along with this library; if not, write to the Free Software 24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 25 * 26 * Alternatively, the contents of this file may be used under the terms 27 * of either the Mozilla Public License Version 1.1, found at 28 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public 29 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html 30 * (the "GPL"), in which case the provisions of the MPL or the GPL are 31 * applicable instead of those above. If you wish to allow use of your 32 * version of this file only under the terms of one of those two 33 * licenses (the MPL or the GPL) and not to allow others to use your 34 * version of this file under the LGPL, indicate your decision by 35 * deletingthe provisions above and replace them with the notice and 36 * other provisions required by the MPL or the GPL, as the case may be. 37 * If you do not delete the provisions above, a recipient may use your 38 * version of this file under any of the LGPL, the MPL or the GPL. 39 */ 40 41#ifndef Arena_h 42#define Arena_h 43 44// FIXME: We'd always like to use AllocAlignmentInteger for Arena alignment 45// but there is concern over the memory growth this may cause. 46#ifdef WTF_USE_ARENA_ALLOC_ALIGNMENT_INTEGER 47#define ARENA_ALIGN_MASK (sizeof(WTF::AllocAlignmentInteger) - 1) 48#else 49#define ARENA_ALIGN_MASK 3 50#endif 51 52namespace WebCore { 53 54typedef uintptr_t uword; 55 56struct Arena { 57 Arena* next; // next arena 58 uword base; // aligned base address 59 uword limit; // end of arena (1+last byte) 60 uword avail; // points to next available byte in arena 61}; 62 63struct ArenaPool { 64 Arena first; // first arena in pool list. 65 Arena* current; // current arena. 66 unsigned int arenasize; 67 uword mask; // Mask (power-of-2 - 1) 68}; 69 70void InitArenaPool(ArenaPool*, const char* name, unsigned int size, unsigned int align); 71void FinishArenaPool(ArenaPool*); 72void* ArenaAllocate(ArenaPool*, unsigned int numBytes, unsigned int& bytesAllocated); 73 74#define ARENA_ALIGN(n) (((uword)(n) + ARENA_ALIGN_MASK) & ~ARENA_ALIGN_MASK) 75#define INIT_ARENA_POOL(pool, name, size) InitArenaPool(pool, name, size, ARENA_ALIGN_MASK + 1) 76#define ARENA_ALLOCATE(p, pool, nb, bytesAllocated) \ 77 Arena* _a = (pool)->current; \ 78 unsigned int _nb = ARENA_ALIGN(nb); \ 79 uword _p = _a->avail; \ 80 uword _q = _p + _nb; \ 81 if (_q > _a->limit) \ 82 _p = (uword)ArenaAllocate(pool, _nb, *bytesAllocated); \ 83 else \ 84 _a->avail = _q; \ 85 p = (void*)_p; 86 87} 88 89#endif 90