PageRenderTime 69ms CodeModel.GetById 22ms app.highlight 6ms RepoModel.GetById 1ms app.codeStats 0ms

/gecko_api/include/plarena.h

http://firefox-mac-pdf.googlecode.com/
C++ Header | 213 lines | 135 code | 29 blank | 49 comment | 10 complexity | 6df13aa8748030f50216a0a056d02b47 MD5 | raw file
  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
 51PR_BEGIN_EXTERN_C
 52
 53typedef struct PLArena          PLArena;
 54
 55struct 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
 63typedef struct PLArenaStats PLArenaStats;
 64
 65struct 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
 83struct 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
187PR_EXTERN(void) PL_ArenaCountAllocation(PLArenaPool *pool, PRUint32 nb);
188
189PR_EXTERN(void) PL_ArenaCountInplaceGrowth(
190    PLArenaPool *pool, PRUint32 size, PRUint32 incr);
191
192PR_EXTERN(void) PL_ArenaCountGrowth(
193    PLArenaPool *pool, PRUint32 size, PRUint32 incr);
194
195PR_EXTERN(void) PL_ArenaCountRelease(PLArenaPool *pool, char *mark);
196
197PR_EXTERN(void) PL_ArenaCountRetract(PLArenaPool *pool, char *mark);
198
199PR_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
211PR_END_EXTERN_C
212
213#endif /* plarena_h___ */