/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* * The contents of this file are subject to the Netscape Public License * Version 1.1 (the "NPL"); you may not use this file except in * compliance with the NPL. You may obtain a copy of the NPL at * http://www.mozilla.org/NPL/ * * Software distributed under the NPL is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL * for the specific language governing rights and limitations under the * NPL. * * The Initial Developer of this code under the NPL is Netscape * Communications Corporation. Portions created by Netscape are * Copyright (C) 1998 Netscape Communications Corporation. All Rights * Reserved. */ #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, nb); \ PRUword _p = _a->avail; \ PRUword _q = _p + _nb; \ if (_q > _a->limit) \ _p = (PRUword)PL_ArenaAllocate(pool, _nb); \ else \ _a->avail = _q; \ p = (void *)_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, incr); \ PRUword _p = _a->avail; \ PRUword _q = _p + _incr; \ if (_p == (PRUword)(p) + PL_ARENA_ALIGN(pool, size) && \ _q <= _a->limit) { \ _a->avail = _q; \ PL_ArenaCountInplaceGrowth(pool, size, incr); \ } else { \ p = PL_ArenaGrow(pool, p, size, incr); \ } \ PL_ArenaCountGrowth(pool, size, 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 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___ */