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 (at) adacel.com.au> 8 * Jeff Hostetler <jeff (at) nerdone.com> 9 * Tom Rini <trini (at) kernel.crashing.org> 10 * Raffaele Sena <raff (at) 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 #include <wtf/FastMalloc.h> 45 46 // FIXME: We'd always like to use AllocAlignmentInteger for Arena alignment 47 // but there is concern over the memory growth this may cause. 48 #ifdef WTF_USE_ARENA_ALLOC_ALIGNMENT_INTEGER 49 #define ARENA_ALIGN_MASK (sizeof(WTF::AllocAlignmentInteger) - 1) 50 #else 51 #define ARENA_ALIGN_MASK 3 52 #endif 53 54 namespace WebCore { 55 56 typedef uintptr_t uword; 57 58 struct Arena { 59 Arena* next; // next arena 60 uword base; // aligned base address 61 uword limit; // end of arena (1+last byte) 62 uword avail; // points to next available byte in arena 63 }; 64 65 struct ArenaPool { 66 Arena first; // first arena in pool list. 67 Arena* current; // current arena. 68 unsigned int arenasize; 69 uword mask; // Mask (power-of-2 - 1) 70 }; 71 72 void InitArenaPool(ArenaPool *pool, const char *name, 73 unsigned int size, unsigned int align); 74 void FinishArenaPool(ArenaPool *pool); 75 void FreeArenaPool(ArenaPool *pool); 76 void* ArenaAllocate(ArenaPool *pool, unsigned int nb); 77 78 #define ARENA_ALIGN(n) (((uword)(n) + ARENA_ALIGN_MASK) & ~ARENA_ALIGN_MASK) 79 #define INIT_ARENA_POOL(pool, name, size) \ 80 InitArenaPool(pool, name, size, ARENA_ALIGN_MASK + 1) 81 82 #define ARENA_ALLOCATE(p, pool, nb) \ 83 Arena *_a = (pool)->current; \ 84 unsigned int _nb = ARENA_ALIGN(nb); \ 85 uword _p = _a->avail; \ 86 uword _q = _p + _nb; \ 87 if (_q > _a->limit) \ 88 _p = (uword)ArenaAllocate(pool, _nb); \ 89 else \ 90 _a->avail = _q; \ 91 p = (void *)_p; 92 93 #define ARENA_GROW(p, pool, size, incr) \ 94 Arena *_a = (pool)->current; \ 95 unsigned int _incr = ARENA_ALIGN(incr); \ 96 uword _p = _a->avail; \ 97 uword _q = _p + _incr; \ 98 if (_p == (uword)(p) + ARENA_ALIGN(size) && \ 99 _q <= _a->limit) { \ 100 _a->avail = _q; \ 101 } else { \ 102 p = ArenaGrow(pool, p, size, incr); \ 103 } 104 105 #define ARENA_MARK(pool) ((void *) (pool)->current->avail) 106 #define UPTRDIFF(p,q) ((uword)(p) - (uword)(q)) 107 108 #ifdef DEBUG 109 #define FREE_PATTERN 0xDA 110 #define CLEAR_UNUSED(a) ASSERT((a)->avail <= (a)->limit); \ 111 memset((void*)(a)->avail, FREE_PATTERN, \ 112 (a)->limit - (a)->avail) 113 #define CLEAR_ARENA(a) memset((void*)(a), FREE_PATTERN, \ 114 (a)->limit - (uword)(a)) 115 #else 116 #define CLEAR_UNUSED(a) 117 #define CLEAR_ARENA(a) 118 #endif 119 120 #define ARENA_RELEASE(pool, mark) \ 121 char *_m = (char *)(mark); \ 122 Arena *_a = (pool)->current; \ 123 if (UPTRDIFF(_m, _a->base) <= UPTRDIFF(_a->avail, _a->base)) { \ 124 _a->avail = (uword)ARENA_ALIGN(_m); \ 125 CLEAR_UNUSED(_a); \ 126 } else { \ 127 ArenaRelease(pool, _m); \ 128 } 129 130 #define ARENA_DESTROY(pool, a, pnext) \ 131 if ((pool)->current == (a)) (pool)->current = &(pool)->first; \ 132 *(pnext) = (a)->next; \ 133 CLEAR_ARENA(a); \ 134 fastFree(a); \ 135 (a) = 0; 136 137 } 138 139 #endif 140
