1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* ***** BEGIN LICENSE BLOCK ***** 3 * Version: MPL 1.1/GPL 2.0/LGPL 2.1 4 * 5 * The contents of this file are subject to the Mozilla Public License Version 6 * 1.1 (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * http://www.mozilla.org/MPL/ 9 * 10 * Software distributed under the License is distributed on an "AS IS" basis, 11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 12 * for the specific language governing rights and limitations under the 13 * License. 14 * 15 * The Original Code is the Netscape Portable Runtime (NSPR). 16 * 17 * The Initial Developer of the Original Code is Netscape 18 * Communications Corporation. Portions created by Netscape are 19 * Copyright (C) 1998-2000 Netscape Communications Corporation. All 20 * Rights Reserved. 21 * 22 * Contributor(s): 23 * 24 * Alternatively, the contents of this file may be used under the terms of 25 * either the GNU General Public License Version 2 or later (the "GPL"), or 26 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), 27 * in which case the provisions of the GPL or the LGPL are applicable instead 28 * of those above. If you wish to allow use of your version of this file only 29 * under the terms of either the GPL or the LGPL, and not to allow others to 30 * use your version of this file under the terms of the MPL, indicate your 31 * decision by deleting the provisions above and replace them with the notice 32 * and other provisions required by the GPL or the LGPL. If you do not delete 33 * the provisions above, a recipient may use your version of this file under 34 * the terms of any one of the MPL, the GPL or the LGPL. 35 * 36 * ***** END LICENSE BLOCK ***** 37 */ 38 39 #ifndef plarena_h___ 40 #define plarena_h___ 41 /* 42 * Lifetime-based fast allocation, inspired by much prior art, including 43 * "Fast Allocation and Deallocation of Memory Based on Object Lifetimes" 44 * David R. Hanson, Software -- Practice and Experience, Vol. 20(1). 45 * 46 * Also supports LIFO allocation (PL_ARENA_MARK/PL_ARENA_RELEASE). 47 */ 48 #include "prtypes.h" 49 #include "plarenas.h" 50 51 PR_BEGIN_EXTERN_C 52 53 typedef struct PLArena PLArena; 54 55 struct PLArena { 56 PLArena *next; /* next arena for this lifetime */ 57 PRUword base; /* aligned base address, follows this header */ 58 PRUword limit; /* one beyond last byte in arena */ 59 PRUword avail; /* points to next available byte */ 60 }; 61 62 #ifdef PL_ARENAMETER 63 typedef struct PLArenaStats PLArenaStats; 64 65 struct PLArenaStats { 66 PLArenaStats *next; /* next in arenaStats list */ 67 char *name; /* name for debugging */ 68 PRUint32 narenas; /* number of arenas in pool */ 69 PRUint32 nallocs; /* number of PL_ARENA_ALLOCATE() calls */ 70 PRUint32 nreclaims; /* number of reclaims from freeArenas */ 71 PRUint32 nmallocs; /* number of malloc() calls */ 72 PRUint32 ndeallocs; /* number of lifetime deallocations */ 73 PRUint32 ngrows; /* number of PL_ARENA_GROW() calls */ 74 PRUint32 ninplace; /* number of in-place growths */ 75 PRUint32 nreleases; /* number of PL_ARENA_RELEASE() calls */ 76 PRUint32 nfastrels; /* number of "fast path" releases */ 77 PRUint32 nbytes; /* total bytes allocated */ 78 PRUint32 maxalloc; /* maximum allocation size in bytes */ 79 PRFloat64 variance; /* size variance accumulator */ 80 }; 81 #endif 82 83 struct PLArenaPool { 84 PLArena first; /* first arena in pool list */ 85 PLArena *current; /* arena from which to allocate space */ 86 PRUint32 arenasize; /* net exact size of a new arena */ 87 PRUword mask; /* alignment mask (power-of-2 - 1) */ 88 #ifdef PL_ARENAMETER 89 PLArenaStats stats; 90 #endif 91 }; 92 93 /* 94 * If the including .c file uses only one power-of-2 alignment, it may define 95 * PL_ARENA_CONST_ALIGN_MASK to the alignment mask and save a few instructions 96 * per ALLOCATE and GROW. 97 */ 98 #ifdef PL_ARENA_CONST_ALIGN_MASK 99 #define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + PL_ARENA_CONST_ALIGN_MASK) \ 100 & ~PL_ARENA_CONST_ALIGN_MASK) 101 102 #define PL_INIT_ARENA_POOL(pool, name, size) \ 103 PL_InitArenaPool(pool, name, size, PL_ARENA_CONST_ALIGN_MASK + 1) 104 #else 105 #define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + (pool)->mask) & ~(pool)->mask) 106 #endif 107 108 #define PL_ARENA_ALLOCATE(p, pool, nb) \ 109 PR_BEGIN_MACRO \ 110 PLArena *_a = (pool)->current; \ 111 PRUint32 _nb = PL_ARENA_ALIGN(pool, nb); \ 112 PRUword _p = _a->avail; \ 113 PRUword _q = _p + _nb; \ 114 if (_q > _a->limit) \ 115 _p = (PRUword)PL_ArenaAllocate(pool, _nb); \ 116 else \ 117 _a->avail = _q; \ 118 p = (void *)_p; \ 119 PL_ArenaCountAllocation(pool, nb); \ 120 PR_END_MACRO 121 122 #define PL_ARENA_GROW(p, pool, size, incr) \ 123 PR_BEGIN_MACRO \ 124 PLArena *_a = (pool)->current; \ 125 PRUint32 _incr = PL_ARENA_ALIGN(pool, incr); \ 126 PRUword _p = _a->avail; \ 127 PRUword _q = _p + _incr; \ 128 if (_p == (PRUword)(p) + PL_ARENA_ALIGN(pool, size) && \ 129 _q <= _a->limit) { \ 130 _a->avail = _q; \ 131 PL_ArenaCountInplaceGrowth(pool, size, incr); \ 132 } else { \ 133 p = PL_ArenaGrow(pool, p, size, incr); \ 134 } \ 135 PL_ArenaCountGrowth(pool, size, incr); \ 136 PR_END_MACRO 137 138 #define PL_ARENA_MARK(pool) ((void *) (pool)->current->avail) 139 #define PR_UPTRDIFF(p,q) ((PRUword)(p) - (PRUword)(q)) 140 141 #ifdef DEBUG 142 #define PL_FREE_PATTERN 0xDA 143 #define PL_CLEAR_UNUSED(a) (PR_ASSERT((a)->avail <= (a)->limit), \ 144 memset((void*)(a)->avail, PL_FREE_PATTERN, \ 145 (a)->limit - (a)->avail)) 146 #define PL_CLEAR_ARENA(a) memset((void*)(a), PL_FREE_PATTERN, \ 147 (a)->limit - (PRUword)(a)) 148 #else 149 #define PL_CLEAR_UNUSED(a) 150 #define PL_CLEAR_ARENA(a) 151 #endif 152 153 #define PL_ARENA_RELEASE(pool, mark) \ 154 PR_BEGIN_MACRO \ 155 char *_m = (char *)(mark); \ 156 PLArena *_a = (pool)->current; \ 157 if (PR_UPTRDIFF(_m, _a->base) <= PR_UPTRDIFF(_a->avail, _a->base)) { \ 158 _a->avail = (PRUword)PL_ARENA_ALIGN(pool, _m); \ 159 PL_CLEAR_UNUSED(_a); \ 160 PL_ArenaCountRetract(pool, _m); \ 161 } else { \ 162 PL_ArenaRelease(pool, _m); \ 163 } \ 164 PL_ArenaCountRelease(pool, _m); \ 165 PR_END_MACRO 166 167 #ifdef PL_ARENAMETER 168 #define PL_COUNT_ARENA(pool,op) ((pool)->stats.narenas op) 169 #else 170 #define PL_COUNT_ARENA(pool,op) 171 #endif 172 173 #define PL_ARENA_DESTROY(pool, a, pnext) \ 174 PR_BEGIN_MACRO \ 175 PL_COUNT_ARENA(pool,--); \ 176 if ((pool)->current == (a)) (pool)->current = &(pool)->first; \ 177 *(pnext) = (a)->next; \ 178 PL_CLEAR_ARENA(a); \ 179 free(a); \ 180 (a) = 0; \ 181 PR_END_MACRO 182 183 #ifdef PL_ARENAMETER 184 185 #include <stdio.h> 186 187 PR_EXTERN(void) PL_ArenaCountAllocation(PLArenaPool *pool, PRUint32 nb); 188 189 PR_EXTERN(void) PL_ArenaCountInplaceGrowth( 190 PLArenaPool *pool, PRUint32 size, PRUint32 incr); 191 192 PR_EXTERN(void) PL_ArenaCountGrowth( 193 PLArenaPool *pool, PRUint32 size, PRUint32 incr); 194 195 PR_EXTERN(void) PL_ArenaCountRelease(PLArenaPool *pool, char *mark); 196 197 PR_EXTERN(void) PL_ArenaCountRetract(PLArenaPool *pool, char *mark); 198 199 PR_EXTERN(void) PL_DumpArenaStats(FILE *fp); 200 201 #else /* !PL_ARENAMETER */ 202 203 #define PL_ArenaCountAllocation(ap, nb) /* nothing */ 204 #define PL_ArenaCountInplaceGrowth(ap, size, incr) /* nothing */ 205 #define PL_ArenaCountGrowth(ap, size, incr) /* nothing */ 206 #define PL_ArenaCountRelease(ap, mark) /* nothing */ 207 #define PL_ArenaCountRetract(ap, mark) /* nothing */ 208 209 #endif /* !PL_ARENAMETER */ 210 211 PR_END_EXTERN_C 212 213 #endif /* plarena_h___ */ 214
