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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is the Netscape Portable Runtime (NSPR).
+ *
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation. Portions created by Netscape are
+ * Copyright (C) 1998-2000 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK *****
+ */
+
+#ifndef plarena_h___
+#define plarena_h___
+/*
+ * Lifetime-based fast allocation, inspired by much prior art, including
+ * "Fast Allocation and Deallocation of Memory Based on Object Lifetimes"
+ * David R. Hanson, Software -- Practice and Experience, Vol. 20(1).
+ *
+ * Also supports LIFO allocation (PL_ARENA_MARK/PL_ARENA_RELEASE).
+ */
+#include "prtypes.h"
+#include "plarenas.h"
+
+PR_BEGIN_EXTERN_C
+
+typedef struct PLArena PLArena;
+
+struct PLArena {
+ PLArena *next; /* next arena for this lifetime */
+ PRUword base; /* aligned base address, follows this header */
+ PRUword limit; /* one beyond last byte in arena */
+ PRUword avail; /* points to next available byte */
+};
+
+#ifdef PL_ARENAMETER
+typedef struct PLArenaStats PLArenaStats;
+
+struct PLArenaStats {
+ PLArenaStats *next; /* next in arenaStats list */
+ char *name; /* name for debugging */
+ PRUint32 narenas; /* number of arenas in pool */
+ PRUint32 nallocs; /* number of PL_ARENA_ALLOCATE() calls */
+ PRUint32 nreclaims; /* number of reclaims from freeArenas */
+ PRUint32 nmallocs; /* number of malloc() calls */
+ PRUint32 ndeallocs; /* number of lifetime deallocations */
+ PRUint32 ngrows; /* number of PL_ARENA_GROW() calls */
+ PRUint32 ninplace; /* number of in-place growths */
+ PRUint32 nreleases; /* number of PL_ARENA_RELEASE() calls */
+ PRUint32 nfastrels; /* number of "fast path" releases */
+ PRUint32 nbytes; /* total bytes allocated */
+ PRUint32 maxalloc; /* maximum allocation size in bytes */
+ PRFloat64 variance; /* size variance accumulator */
+};
+#endif
+
+struct PLArenaPool {
+ PLArena first; /* first arena in pool list */
+ PLArena *current; /* arena from which to allocate space */
+ PRUint32 arenasize; /* net exact size of a new arena */
+ PRUword mask; /* alignment mask (power-of-2 - 1) */
+#ifdef PL_ARENAMETER
+ PLArenaStats stats;
+#endif
+};
+
+/*
+ * If the including .c file uses only one power-of-2 alignment, it may define
+ * PL_ARENA_CONST_ALIGN_MASK to the alignment mask and save a few instructions
+ * per ALLOCATE and GROW.
+ */
+#ifdef PL_ARENA_CONST_ALIGN_MASK
+#define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + PL_ARENA_CONST_ALIGN_MASK) \
+ & ~PL_ARENA_CONST_ALIGN_MASK)
+
+#define PL_INIT_ARENA_POOL(pool, name, size) \
+ PL_InitArenaPool(pool, name, size, PL_ARENA_CONST_ALIGN_MASK + 1)
+#else
+#define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + (pool)->mask) & ~(pool)->mask)
+#endif
+
+#define PL_ARENA_ALLOCATE(p, pool, nb) \
+ PR_BEGIN_MACRO \
+ PLArena *_a = (pool)->current; \
+ PRUint32 _nb = PL_ARENA_ALIGN(pool, (PRUint32)nb); \
+ PRUword _p = _a->avail; \
+ if (_nb < (PRUint32)nb) { \
+ _p = 0; \
+ } else if (_nb > (_a->limit - _a->avail)) { \
+ _p = (PRUword)PL_ArenaAllocate(pool, _nb); \
+ } else { \
+ _a->avail += _nb; \
+ } \
+ p = (void *)_p; \
+ if (p) { \
+ PL_ArenaCountAllocation(pool, nb); \
+ } \
+ PR_END_MACRO
+
+#define PL_ARENA_GROW(p, pool, size, incr) \
+ PR_BEGIN_MACRO \
+ PLArena *_a = (pool)->current; \
+ PRUint32 _incr = PL_ARENA_ALIGN(pool, (PRUint32)incr); \
+ if (_incr < (PRUint32)incr) { \
+ p = NULL; \
+ } else if (_a->avail == (PRUword)(p) + PL_ARENA_ALIGN(pool, size) && \
+ _incr <= (_a->limit - _a->avail)) { \
+ _a->avail = _incr; \
+ PL_ArenaCountInplaceGrowth(pool, size, (RTUint32)incr); \
+ } else { \
+ p = PL_ArenaGrow(pool, p, size, (PRUint32)incr); \
+ } \
+ if (p) { \
+ PL_ArenaCountGrowth(pool, size, (PRUint32)incr); \
+ } \
+ PR_END_MACRO
+
+#define PL_ARENA_MARK(pool) ((void *) (pool)->current->avail)
+#define PR_UPTRDIFF(p,q) ((PRUword)(p) - (PRUword)(q))
+
+#ifdef DEBUG
+#define PL_FREE_PATTERN 0xDA
+#define PL_CLEAR_UNUSED(a) (PR_ASSERT((a)->avail <= (a)->limit), \
+ memset((void*)(a)->avail, PL_FREE_PATTERN, \
+ (a)->limit - (a)->avail))
+#define PL_CLEAR_ARENA(a) memset((void*)(a), PL_FREE_PATTERN, \
+ (a)->limit - (PRUword)(a))
+#else
+#define PL_CLEAR_UNUSED(a)
+#define PL_CLEAR_ARENA(a)
+#endif
+
+#define PL_ARENA_RELEASE(pool, mark) \
+ PR_BEGIN_MACRO \
+ char *_m = (char *)(mark); \
+ PLArena *_a = (pool)->current; \
+ if (PR_UPTRDIFF(_m, _a->base) <= PR_UPTRDIFF(_a->avail, _a->base)) { \
+ _a->avail = (PRUword)PL_ARENA_ALIGN(pool, _m); \
+ PL_CLEAR_UNUSED(_a); \
+ PL_ArenaCountRetract(pool, _m); \
+ } else { \
+ PL_ArenaRelease(pool, _m); \
+ } \
+ PL_ArenaCountRelease(pool, _m); \
+ PR_END_MACRO
+
+#ifdef PL_ARENAMETER
+#define PL_COUNT_ARENA(pool,op) ((pool)->stats.narenas op)
+#else
+#define PL_COUNT_ARENA(pool,op)
+#endif
+
+#define PL_ARENA_DESTROY(pool, a, pnext) \
+ PR_BEGIN_MACRO \
+ PL_COUNT_ARENA(pool,--); \
+ if ((pool)->current == (a)) (pool)->current = &(pool)->first; \
+ *(pnext) = (a)->next; \
+ PL_CLEAR_ARENA(a); \
+ free(a); \
+ (a) = 0; \
+ PR_END_MACRO
+
+#ifdef PL_ARENAMETER
+
+#include <stdio.h>
+
+PR_EXTERN(void) PL_ArenaCountAllocation(PLArenaPool *pool, PRUint32 nb);
+
+PR_EXTERN(void) PL_ArenaCountInplaceGrowth(
+ PLArenaPool *pool, PRUint32 size, PRUint32 incr);
+
+PR_EXTERN(void) PL_ArenaCountGrowth(
+ PLArenaPool *pool, PRUint32 size, PRUint32 incr);
+
+PR_EXTERN(void) PL_ArenaCountRelease(PLArenaPool *pool, char *mark);
+
+PR_EXTERN(void) PL_ArenaCountRetract(PLArenaPool *pool, char *mark);
+
+PR_EXTERN(void) PL_DumpArenaStats(FILE *fp);
+
+#else /* !PL_ARENAMETER */
+
+#define PL_ArenaCountAllocation(ap, nb) /* nothing */
+#define PL_ArenaCountInplaceGrowth(ap, size, incr) /* nothing */
+#define PL_ArenaCountGrowth(ap, size, incr) /* nothing */
+#define PL_ArenaCountRelease(ap, mark) /* nothing */
+#define PL_ArenaCountRetract(ap, mark) /* nothing */
+
+#endif /* !PL_ARENAMETER */
+
+PR_END_EXTERN_C
+
+#endif /* plarena_h___ */