1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/nsprpub/lib/ds/plarena.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,253 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef plarena_h___
1.10 +#define plarena_h___
1.11 +/*
1.12 + * Lifetime-based fast allocation, inspired by much prior art, including
1.13 + * "Fast Allocation and Deallocation of Memory Based on Object Lifetimes"
1.14 + * David R. Hanson, Software -- Practice and Experience, Vol. 20(1).
1.15 + *
1.16 + * Also supports LIFO allocation (PL_ARENA_MARK/PL_ARENA_RELEASE).
1.17 + */
1.18 +#include "prtypes.h"
1.19 +#include "plarenas.h"
1.20 +
1.21 +PR_BEGIN_EXTERN_C
1.22 +
1.23 +typedef struct PLArena PLArena;
1.24 +
1.25 +struct PLArena {
1.26 + PLArena *next; /* next arena for this lifetime */
1.27 + PRUword base; /* aligned base address, follows this header */
1.28 + PRUword limit; /* one beyond last byte in arena */
1.29 + PRUword avail; /* points to next available byte */
1.30 +};
1.31 +
1.32 +#ifdef PL_ARENAMETER
1.33 +typedef struct PLArenaStats PLArenaStats;
1.34 +
1.35 +struct PLArenaStats {
1.36 + PLArenaStats *next; /* next in arenaStats list */
1.37 + char *name; /* name for debugging */
1.38 + PRUint32 narenas; /* number of arenas in pool */
1.39 + PRUint32 nallocs; /* number of PL_ARENA_ALLOCATE() calls */
1.40 + PRUint32 nreclaims; /* number of reclaims from freeArenas */
1.41 + PRUint32 nmallocs; /* number of malloc() calls */
1.42 + PRUint32 ndeallocs; /* number of lifetime deallocations */
1.43 + PRUint32 ngrows; /* number of PL_ARENA_GROW() calls */
1.44 + PRUint32 ninplace; /* number of in-place growths */
1.45 + PRUint32 nreleases; /* number of PL_ARENA_RELEASE() calls */
1.46 + PRUint32 nfastrels; /* number of "fast path" releases */
1.47 + PRUint32 nbytes; /* total bytes allocated */
1.48 + PRUint32 maxalloc; /* maximum allocation size in bytes */
1.49 + PRFloat64 variance; /* size variance accumulator */
1.50 +};
1.51 +#endif
1.52 +
1.53 +struct PLArenaPool {
1.54 + PLArena first; /* first arena in pool list */
1.55 + PLArena *current; /* arena from which to allocate space */
1.56 + PRUint32 arenasize; /* net exact size of a new arena */
1.57 + PRUword mask; /* alignment mask (power-of-2 - 1) */
1.58 +#ifdef PL_ARENAMETER
1.59 + PLArenaStats stats;
1.60 +#endif
1.61 +};
1.62 +
1.63 +/*
1.64 + * WARNING: The PL_MAKE_MEM_ macros are for internal use by NSPR. Do NOT use
1.65 + * them in your code.
1.66 + *
1.67 + * NOTE: Valgrind support to be added.
1.68 + *
1.69 + * The PL_MAKE_MEM_ macros are modeled after the MOZ_MAKE_MEM_ macros in
1.70 + * Mozilla's mfbt/MemoryChecking.h. Only AddressSanitizer is supported now.
1.71 + *
1.72 + * Provides a common interface to the ASan (AddressSanitizer) and Valgrind
1.73 + * functions used to mark memory in certain ways. In detail, the following
1.74 + * three macros are provided:
1.75 + *
1.76 + * PL_MAKE_MEM_NOACCESS - Mark memory as unsafe to access (e.g. freed)
1.77 + * PL_MAKE_MEM_UNDEFINED - Mark memory as accessible, with content undefined
1.78 + * PL_MAKE_MEM_DEFINED - Mark memory as accessible, with content defined
1.79 + *
1.80 + * With Valgrind in use, these directly map to the three respective Valgrind
1.81 + * macros. With ASan in use, the NOACCESS macro maps to poisoning the memory,
1.82 + * while the UNDEFINED/DEFINED macros unpoison memory.
1.83 + *
1.84 + * With no memory checker available, all macros expand to the empty statement.
1.85 + */
1.86 +
1.87 +/* WARNING: PL_SANITIZE_ADDRESS is for internal use by this header. Do NOT
1.88 + * define or test this macro in your code.
1.89 + */
1.90 +#if defined(__has_feature)
1.91 +#if __has_feature(address_sanitizer)
1.92 +#define PL_SANITIZE_ADDRESS 1
1.93 +#endif
1.94 +#elif defined(__SANITIZE_ADDRESS__)
1.95 +#define PL_SANITIZE_ADDRESS 1
1.96 +#endif
1.97 +
1.98 +#if defined(PL_SANITIZE_ADDRESS)
1.99 +
1.100 +/* These definitions are usually provided through the
1.101 + * sanitizer/asan_interface.h header installed by ASan.
1.102 + * See https://code.google.com/p/address-sanitizer/wiki/ManualPoisoning
1.103 + */
1.104 +
1.105 +void __asan_poison_memory_region(void const volatile *addr, size_t size);
1.106 +void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
1.107 +
1.108 +#define PL_MAKE_MEM_NOACCESS(addr, size) \
1.109 + __asan_poison_memory_region((addr), (size))
1.110 +
1.111 +#define PL_MAKE_MEM_UNDEFINED(addr, size) \
1.112 + __asan_unpoison_memory_region((addr), (size))
1.113 +
1.114 +#define PL_MAKE_MEM_DEFINED(addr, size) \
1.115 + __asan_unpoison_memory_region((addr), (size))
1.116 +
1.117 +#else
1.118 +
1.119 +#define PL_MAKE_MEM_NOACCESS(addr, size)
1.120 +#define PL_MAKE_MEM_UNDEFINED(addr, size)
1.121 +#define PL_MAKE_MEM_DEFINED(addr, size)
1.122 +
1.123 +#endif
1.124 +
1.125 +/*
1.126 + * If the including .c file uses only one power-of-2 alignment, it may define
1.127 + * PL_ARENA_CONST_ALIGN_MASK to the alignment mask and save a few instructions
1.128 + * per ALLOCATE and GROW.
1.129 + */
1.130 +#ifdef PL_ARENA_CONST_ALIGN_MASK
1.131 +#define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + PL_ARENA_CONST_ALIGN_MASK) \
1.132 + & ~PL_ARENA_CONST_ALIGN_MASK)
1.133 +
1.134 +#define PL_INIT_ARENA_POOL(pool, name, size) \
1.135 + PL_InitArenaPool(pool, name, size, PL_ARENA_CONST_ALIGN_MASK + 1)
1.136 +#else
1.137 +#define PL_ARENA_ALIGN(pool, n) (((PRUword)(n) + (pool)->mask) & ~(pool)->mask)
1.138 +#endif
1.139 +
1.140 +#define PL_ARENA_ALLOCATE(p, pool, nb) \
1.141 + PR_BEGIN_MACRO \
1.142 + PLArena *_a = (pool)->current; \
1.143 + PRUint32 _nb = PL_ARENA_ALIGN(pool, nb); \
1.144 + PRUword _p = _a->avail; \
1.145 + PRUword _q = _p + _nb; \
1.146 + if (_q > _a->limit) { \
1.147 + _p = (PRUword)PL_ArenaAllocate(pool, _nb); \
1.148 + } else { \
1.149 + _a->avail = _q; \
1.150 + } \
1.151 + p = (void *)_p; \
1.152 + PL_MAKE_MEM_UNDEFINED(p, nb); \
1.153 + PL_ArenaCountAllocation(pool, nb); \
1.154 + PR_END_MACRO
1.155 +
1.156 +#define PL_ARENA_GROW(p, pool, size, incr) \
1.157 + PR_BEGIN_MACRO \
1.158 + PLArena *_a = (pool)->current; \
1.159 + PRUint32 _incr = PL_ARENA_ALIGN(pool, incr); \
1.160 + PRUword _p = _a->avail; \
1.161 + PRUword _q = _p + _incr; \
1.162 + if (_p == (PRUword)(p) + PL_ARENA_ALIGN(pool, size) && \
1.163 + _q <= _a->limit) { \
1.164 + PL_MAKE_MEM_UNDEFINED((unsigned char *)(p) + size, incr); \
1.165 + _a->avail = _q; \
1.166 + PL_ArenaCountInplaceGrowth(pool, size, incr); \
1.167 + } else { \
1.168 + p = PL_ArenaGrow(pool, p, size, incr); \
1.169 + } \
1.170 + PL_ArenaCountGrowth(pool, size, incr); \
1.171 + PR_END_MACRO
1.172 +
1.173 +#define PL_ARENA_MARK(pool) ((void *) (pool)->current->avail)
1.174 +#define PR_UPTRDIFF(p,q) ((PRUword)(p) - (PRUword)(q))
1.175 +
1.176 +#define PL_CLEAR_UNUSED_PATTERN(a, pattern) \
1.177 + PR_BEGIN_MACRO \
1.178 + PR_ASSERT((a)->avail <= (a)->limit); \
1.179 + PL_MAKE_MEM_UNDEFINED((void*)(a)->avail, (a)->limit - (a)->avail); \
1.180 + memset((void*)(a)->avail, (pattern), (a)->limit - (a)->avail); \
1.181 + PR_END_MACRO
1.182 +#ifdef DEBUG
1.183 +#define PL_FREE_PATTERN 0xDA
1.184 +#define PL_CLEAR_UNUSED(a) PL_CLEAR_UNUSED_PATTERN((a), PL_FREE_PATTERN)
1.185 +#define PL_CLEAR_ARENA(a) \
1.186 + PR_BEGIN_MACRO \
1.187 + PL_MAKE_MEM_UNDEFINED((void*)(a), (a)->limit - (PRUword)(a)); \
1.188 + memset((void*)(a), PL_FREE_PATTERN, (a)->limit - (PRUword)(a)); \
1.189 + PR_END_MACRO
1.190 +#else
1.191 +#define PL_CLEAR_UNUSED(a)
1.192 +#define PL_CLEAR_ARENA(a)
1.193 +#endif
1.194 +
1.195 +#define PL_ARENA_RELEASE(pool, mark) \
1.196 + PR_BEGIN_MACRO \
1.197 + char *_m = (char *)(mark); \
1.198 + PLArena *_a = (pool)->current; \
1.199 + if (PR_UPTRDIFF(_m, _a->base) <= PR_UPTRDIFF(_a->avail, _a->base)) { \
1.200 + _a->avail = (PRUword)PL_ARENA_ALIGN(pool, _m); \
1.201 + PL_CLEAR_UNUSED(_a); \
1.202 + PL_MAKE_MEM_NOACCESS((void*)_a->avail, _a->limit - _a->avail); \
1.203 + PL_ArenaCountRetract(pool, _m); \
1.204 + } else { \
1.205 + PL_ArenaRelease(pool, _m); \
1.206 + } \
1.207 + PL_ArenaCountRelease(pool, _m); \
1.208 + PR_END_MACRO
1.209 +
1.210 +#ifdef PL_ARENAMETER
1.211 +#define PL_COUNT_ARENA(pool,op) ((pool)->stats.narenas op)
1.212 +#else
1.213 +#define PL_COUNT_ARENA(pool,op)
1.214 +#endif
1.215 +
1.216 +#define PL_ARENA_DESTROY(pool, a, pnext) \
1.217 + PR_BEGIN_MACRO \
1.218 + PL_COUNT_ARENA(pool,--); \
1.219 + if ((pool)->current == (a)) (pool)->current = &(pool)->first; \
1.220 + *(pnext) = (a)->next; \
1.221 + PL_CLEAR_ARENA(a); \
1.222 + free(a); \
1.223 + (a) = 0; \
1.224 + PR_END_MACRO
1.225 +
1.226 +#ifdef PL_ARENAMETER
1.227 +
1.228 +#include <stdio.h>
1.229 +
1.230 +PR_EXTERN(void) PL_ArenaCountAllocation(PLArenaPool *pool, PRUint32 nb);
1.231 +
1.232 +PR_EXTERN(void) PL_ArenaCountInplaceGrowth(
1.233 + PLArenaPool *pool, PRUint32 size, PRUint32 incr);
1.234 +
1.235 +PR_EXTERN(void) PL_ArenaCountGrowth(
1.236 + PLArenaPool *pool, PRUint32 size, PRUint32 incr);
1.237 +
1.238 +PR_EXTERN(void) PL_ArenaCountRelease(PLArenaPool *pool, char *mark);
1.239 +
1.240 +PR_EXTERN(void) PL_ArenaCountRetract(PLArenaPool *pool, char *mark);
1.241 +
1.242 +PR_EXTERN(void) PL_DumpArenaStats(FILE *fp);
1.243 +
1.244 +#else /* !PL_ARENAMETER */
1.245 +
1.246 +#define PL_ArenaCountAllocation(ap, nb) /* nothing */
1.247 +#define PL_ArenaCountInplaceGrowth(ap, size, incr) /* nothing */
1.248 +#define PL_ArenaCountGrowth(ap, size, incr) /* nothing */
1.249 +#define PL_ArenaCountRelease(ap, mark) /* nothing */
1.250 +#define PL_ArenaCountRetract(ap, mark) /* nothing */
1.251 +
1.252 +#endif /* !PL_ARENAMETER */
1.253 +
1.254 +PR_END_EXTERN_C
1.255 +
1.256 +#endif /* plarena_h___ */
