1/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2/* 3 * The contents of this file are subject to the Mozilla Public 4 * License Version 1.1 (the "License"); you may not use this file 5 * except in compliance with the License. You may obtain a copy of 6 * the License at http://www.mozilla.org/MPL/ 7 * 8 * Software distributed under the License is distributed on an "AS 9 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or 10 * implied. See the License for the specific language governing 11 * rights and limitations under the License. 12 * 13 * The Original Code is the Netscape Portable Runtime (NSPR). 14 * 15 * The Initial Developer of the Original Code is Netscape 16 * Communications Corporation. Portions created by Netscape are 17 * Copyright (C) 1998-2000 Netscape Communications Corporation. All 18 * Rights Reserved. 19 * 20 * Contributor(s): 21 * 22 * Alternatively, the contents of this file may be used under the 23 * terms of the GNU General Public License Version 2 or later (the 24 * "GPL"), in which case the provisions of the GPL are applicable 25 * instead of those above. If you wish to allow use of your 26 * version of this file only under the terms of the GPL and not to 27 * allow others to use your version of this file under the MPL, 28 * indicate your decision by deleting the provisions above and 29 * replace them with the notice and other provisions required by 30 * the GPL. If you do not delete the provisions above, a recipient 31 * may use your version of this file under either the MPL or the 32 * GPL. 33 */ 34 35#ifndef plarena_h___ 36#define plarena_h___ 37/* 38 * Lifetime-based fast allocation, inspired by much prior art, including 39 * "Fast Allocation and Deallocation of Memory Based on Object Lifetimes" 40 * David R. Hanson, Software -- Practice and Experience, Vol. 20(1). 41 * 42 * Also supports LIFO allocation (PL_ARENA_MARK/PL_ARENA_RELEASE). 43 */ 44#include "prtypes.h" 45#include "plarenas.h" 46 47PR_BEGIN_EXTERN_C 48 49typedef struct PLArena PLArena; 50 51struct PLArena { 52 PLArena *next; /* next arena for this lifetime */ 53 PRUword base; /* aligned base address, follows this header */ 54 PRUword limit; /* one beyond last byte in arena */ 55 PRUword avail; /* points to next available byte */ 56}; 57 58#ifdef PL_ARENAMETER 59typedef struct PLArenaStats PLArenaStats; 60 61struct PLArenaStats { 62 PLArenaStats *next; /* next in arenaStats list */ 63 char *name; /* name for debugging */ 64 PRUint32 narenas; /* number of arenas in pool */ 65 PRUint32 nallocs; /* number of PL_ARENA_ALLOCATE() calls */ 66 PRUint32 nreclaims; /* number of reclaims from freeArenas */ 67 PRUint32 nmallocs; /* number of malloc() calls */ 68 PRUint32 ndeallocs; /* number of lifetime deallocations */ 69 PRUint32 ngrows; /* number of PL_ARENA_GROW() calls */ 70 PRUint32 ninplace; /* number of in-place growths */ 71 PRUint32 nreleases; /* number of PL_ARENA_RELEASE() calls */ 72 PRUint32 nfastrels; /* number of "fast path" releases */ 73 PRUint32 nbytes; /* total bytes allocated */ 74 PRUint32 maxalloc; /* maximum allocation size in bytes */ 75 PRFloat64 variance; /* size variance accumulator */ 76}; 77#endif 78 79struct PLArenaPool { 80 PLArena first; /* first arena in pool list */ 81 PLArena *current; /* arena from which to allocate space */ 82 PRSize arenasize; /* net exact size of a new arena */ 83 PRUword mask; /* alignment mask (power-of-2 - 1) */ 84#ifdef PL_ARENAMETER 85 PLArenaStats stats; 86#endif 87}; 88 89/* 90 * If the including .c file uses only one power-of-2 alignment, it may define 91 * PL_ARENA_CONST_ALIGN_MASK to the alignment mask and save a few instructions 92 * per ALLOCATE and GROW. 93 */ 94#ifdef PL_ARENA_CONST_ALIGN_MASK 95#define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + PL_ARENA_CONST_ALIGN_MASK) \ 96 & ~PL_ARENA_CONST_ALIGN_MASK) 97 98#define PL_INIT_ARENA_POOL(pool, name, size) \ 99 PL_InitArenaPool(pool, name, size, PL_ARENA_CONST_ALIGN_MASK + 1) 100#else 101#define PL_ARENA_ALIGN(pool, n) (typeof(n))(((PRUword)(n) + (pool)->mask) & ~(pool)->mask) 102#endif 103 104#define PL_ARENA_ALLOCATE(p, pool, nb) \ 105 PR_BEGIN_MACRO \ 106 PLArena *_a = (pool)->current; \ 107 PRUint32 _nb = PL_ARENA_ALIGN(pool, nb); \ 108 PRUword _p = _a->avail; \ 109 PRUword _q = _p + _nb; \ 110 if (_q > _a->limit) \ 111 _p = (PRUword)PL_ArenaAllocate(pool, _nb); \ 112 else \ 113 _a->avail = _q; \ 114 p = (void *)_p; \ 115 PL_ArenaCountAllocation(pool, nb); \ 116 PR_END_MACRO 117 118#define PL_ARENA_GROW(p, pool, size, incr) \ 119 PR_BEGIN_MACRO \ 120 PLArena *_a = (pool)->current; \ 121 PRUword _p = _a->avail; \ 122 PRUword _q = (PRUword)p + size + incr; \ 123 if (_p == (PRUword)(p) + PL_ARENA_ALIGN(pool, size) && \ 124 _q <= _a->limit) { \ 125 _a->avail = PL_ARENA_ALIGN(pool, _q); \ 126 PL_ArenaCountInplaceGrowth(pool, size, incr); \ 127 } else { \ 128 p = PL_ArenaGrow(pool, p, size, incr); \ 129 } \ 130 PL_ArenaCountGrowth(pool, size, incr); \ 131 PR_END_MACRO 132 133#define PL_ARENA_MARK(pool) ((void *) (pool)->current->avail) 134#define PR_UPTRDIFF(p,q) ((PRUword)(p) - (PRUword)(q)) 135 136#ifdef DEBUG 137#define PL_FREE_PATTERN 0xDA 138#define PL_CLEAR_UNUSED(a) (PR_ASSERT((a)->avail <= (a)->limit), \ 139 memset((void*)(a)->avail, PL_FREE_PATTERN, \ 140 (a)->limit - (a)->avail)) 141#define PL_CLEAR_ARENA(a) memset((void*)(a), PL_FREE_PATTERN, \ 142 (a)->limit - (PRUword)(a)) 143#else 144#define PL_CLEAR_UNUSED(a) 145#define PL_CLEAR_ARENA(a) 146#endif 147 148#if ARENA_MARK_ENABLE 149 150#define PL_ARENA_RELEASE(pool, mark) \ 151 PR_BEGIN_MACRO \ 152 char *_m = (char *)(mark); \ 153 PLArena *_a = (pool)->current; \ 154 if (PR_UPTRDIFF(_m, _a->base) <= PR_UPTRDIFF(_a->avail, _a->base)) { \ 155 _a->avail = (PRUword)PL_ARENA_ALIGN(pool, _m); \ 156 PL_CLEAR_UNUSED(_a); \ 157 PL_ArenaCountRetract(pool, _m); \ 158 } else { \ 159 PL_ArenaRelease(pool, _m); \ 160 } \ 161 PL_ArenaCountRelease(pool, _m); \ 162 PR_END_MACRO 163 164#else /* !ARENA_MARK_ENABLE */ 165 166#define PL_ARENA_RELEASE(pool, mark) 167 168#endif /* ARENA_MARK_ENABLE */ 169 170#ifdef PL_ARENAMETER 171#define PL_COUNT_ARENA(pool,op) ((pool)->stats.narenas op) 172#else 173#define PL_COUNT_ARENA(pool,op) 174#endif 175 176#define PL_ARENA_DESTROY(pool, a, pnext) \ 177 PR_BEGIN_MACRO \ 178 PL_COUNT_ARENA(pool,--); \ 179 if ((pool)->current == (a)) (pool)->current = &(pool)->first; \ 180 *(pnext) = (a)->next; \ 181 PL_CLEAR_ARENA(a); \ 182 free(a); \ 183 (a) = 0; \ 184 PR_END_MACRO 185 186#ifdef PL_ARENAMETER 187 188#include <stdio.h> 189 190PR_EXTERN(void) PL_ArenaCountAllocation(PLArenaPool *pool, PRUint32 nb); 191 192PR_EXTERN(void) PL_ArenaCountInplaceGrowth( 193 PLArenaPool *pool, PRUint32 size, PRUint32 incr); 194 195PR_EXTERN(void) PL_ArenaCountGrowth( 196 PLArenaPool *pool, PRUint32 size, PRUint32 incr); 197 198PR_EXTERN(void) PL_ArenaCountRelease(PLArenaPool *pool, char *mark); 199 200PR_EXTERN(void) PL_ArenaCountRetract(PLArenaPool *pool, char *mark); 201 202PR_EXTERN(void) PL_DumpArenaStats(FILE *fp); 203 204#else /* !PL_ARENAMETER */ 205 206#define PL_ArenaCountAllocation(ap, nb) /* nothing */ 207#define PL_ArenaCountInplaceGrowth(ap, size, incr) /* nothing */ 208#define PL_ArenaCountGrowth(ap, size, incr) /* nothing */ 209#define PL_ArenaCountRelease(ap, mark) /* nothing */ 210#define PL_ArenaCountRetract(ap, mark) /* nothing */ 211 212#endif /* !PL_ARENAMETER */ 213 214PR_END_EXTERN_C 215 216#endif /* plarena_h___ */ 217