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Diffstat (limited to 'nsprpub/lib/ds/plarena.h')
| -rw-r--r-- | nsprpub/lib/ds/plarena.h | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/nsprpub/lib/ds/plarena.h b/nsprpub/lib/ds/plarena.h new file mode 100644 index 0000000000..5336a0e4d4 --- /dev/null +++ b/nsprpub/lib/ds/plarena.h @@ -0,0 +1,327 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#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" + +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 + +typedef struct PLArenaPool PLArenaPool; + +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 +}; + +/* + * WARNING: The PL_MAKE_MEM_ macros are for internal use by NSPR. Do NOT use + * them in your code. + * + * NOTE: Valgrind support to be added. + * + * The PL_MAKE_MEM_ macros are modeled after the MOZ_MAKE_MEM_ macros in + * Mozilla's mfbt/MemoryChecking.h. Only AddressSanitizer is supported now. + * + * Provides a common interface to the ASan (AddressSanitizer) and Valgrind + * functions used to mark memory in certain ways. In detail, the following + * three macros are provided: + * + * PL_MAKE_MEM_NOACCESS - Mark memory as unsafe to access (e.g. freed) + * PL_MAKE_MEM_UNDEFINED - Mark memory as accessible, with content undefined + * PL_MAKE_MEM_DEFINED - Mark memory as accessible, with content defined + * + * With Valgrind in use, these directly map to the three respective Valgrind + * macros. With ASan in use, the NOACCESS macro maps to poisoning the memory, + * while the UNDEFINED/DEFINED macros unpoison memory. + * + * With no memory checker available, all macros expand to the empty statement. + */ + +/* WARNING: PL_SANITIZE_ADDRESS is for internal use by this header. Do NOT + * define or test this macro in your code. + */ +#if defined(__has_feature) +#if __has_feature(address_sanitizer) +#define PL_SANITIZE_ADDRESS 1 +#endif +#elif defined(__SANITIZE_ADDRESS__) +#define PL_SANITIZE_ADDRESS 1 +#endif + +#if defined(PL_SANITIZE_ADDRESS) + +/* These definitions are usually provided through the + * sanitizer/asan_interface.h header installed by ASan. + * See https://github.com/google/sanitizers/wiki/AddressSanitizerManualPoisoning + */ + +PR_IMPORT(void) __asan_poison_memory_region(void const volatile *addr, size_t size); +PR_IMPORT(void) __asan_unpoison_memory_region(void const volatile *addr, size_t size); + +#define PL_MAKE_MEM_NOACCESS(addr, size) \ + __asan_poison_memory_region((addr), (size)) + +#define PL_MAKE_MEM_UNDEFINED(addr, size) \ + __asan_unpoison_memory_region((addr), (size)) + +#define PL_MAKE_MEM_DEFINED(addr, size) \ + __asan_unpoison_memory_region((addr), (size)) + +#else + +#define PL_MAKE_MEM_NOACCESS(addr, size) +#define PL_MAKE_MEM_UNDEFINED(addr, size) +#define PL_MAKE_MEM_DEFINED(addr, size) + +#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_MAKE_MEM_UNDEFINED(p, (PRUint32)nb); \ + PL_ArenaCountAllocation(pool, (PRUint32)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)) { \ + PL_MAKE_MEM_UNDEFINED((unsigned char *)(p) + size, (PRUint32)incr); \ + _a->avail += _incr; \ + PL_ArenaCountInplaceGrowth(pool, size, (PRUint32)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)) + +#define PL_CLEAR_UNUSED_PATTERN(a, pattern) \ + PR_BEGIN_MACRO \ + PR_ASSERT((a)->avail <= (a)->limit); \ + PL_MAKE_MEM_UNDEFINED((void*)(a)->avail, (a)->limit - (a)->avail); \ + memset((void*)(a)->avail, (pattern), (a)->limit - (a)->avail); \ + PR_END_MACRO +#ifdef DEBUG +#define PL_FREE_PATTERN 0xDA +#define PL_CLEAR_UNUSED(a) PL_CLEAR_UNUSED_PATTERN((a), PL_FREE_PATTERN) +#define PL_CLEAR_ARENA(a) \ + PR_BEGIN_MACRO \ + PL_MAKE_MEM_UNDEFINED((void*)(a), (a)->limit - (PRUword)(a)); \ + memset((void*)(a), PL_FREE_PATTERN, (a)->limit - (PRUword)(a)); \ + PR_END_MACRO +#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_MAKE_MEM_NOACCESS((void*)_a->avail, _a->limit - _a->avail); \ + 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 + +/* +** Initialize an arena pool with the given name for debugging and metering, +** with a minimum gross size per arena of size bytes. The net size per arena +** is smaller than the gross size by a header of four pointers plus any +** necessary padding for alignment. +** +** Note: choose a gross size that's a power of two to avoid the heap allocator +** rounding the size up. +**/ +PR_EXTERN(void) PL_InitArenaPool( + PLArenaPool *pool, const char *name, PRUint32 size, PRUint32 align); + +/* +** Finish using arenas, freeing all memory associated with them. +** NOTE: this function is now a no-op. If you want to free a single +** PLArenaPoolUse use PL_FreeArenaPool() or PL_FinishArenaPool(). +**/ +PR_EXTERN(void) PL_ArenaFinish(void); + +/* +** Free the arenas in pool. The user may continue to allocate from pool +** after calling this function. There is no need to call PL_InitArenaPool() +** again unless PL_FinishArenaPool(pool) has been called. +**/ +PR_EXTERN(void) PL_FreeArenaPool(PLArenaPool *pool); + +/* +** Free the arenas in pool and finish using it altogether. +**/ +PR_EXTERN(void) PL_FinishArenaPool(PLArenaPool *pool); + +/* +** Compact all of the arenas in a pool so that no space is wasted. +** NOT IMPLEMENTED. Do not use. +**/ +PR_EXTERN(void) PL_CompactArenaPool(PLArenaPool *pool); + +/* +** Friend functions used by the PL_ARENA_*() macros. +** +** WARNING: do not call these functions directly. Always use the +** PL_ARENA_*() macros. +**/ +PR_EXTERN(void *) PL_ArenaAllocate(PLArenaPool *pool, PRUint32 nb); + +PR_EXTERN(void *) PL_ArenaGrow( + PLArenaPool *pool, void *p, PRUint32 size, PRUint32 incr); + +PR_EXTERN(void) PL_ArenaRelease(PLArenaPool *pool, char *mark); + +/* +** memset contents of all arenas in pool to pattern +*/ +PR_EXTERN(void) PL_ClearArenaPool(PLArenaPool *pool, PRInt32 pattern); + +/* +** A function like malloc_size() or malloc_usable_size() that measures the +** size of a heap block. +*/ +typedef size_t (*PLMallocSizeFn)(const void *ptr); + +/* +** Measure all memory used by a PLArenaPool, excluding the PLArenaPool +** structure. +*/ +PR_EXTERN(size_t) PL_SizeOfArenaPoolExcludingPool( + const PLArenaPool *pool, PLMallocSizeFn mallocSizeOf); + +#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___ */ |