/* -*- 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)

#if defined(_MSC_VER)

/* We can't use dllimport due to DLL linkage mismatch with

 * sanitizer/asan_interface.h.

 */

#define PL_ASAN_VISIBILITY(type_) type_

#else

#define PL_ASAN_VISIBILITY(type_) PR_IMPORT(type_)

#endif

/* These definitions are usually provided through the

 * sanitizer/asan_interface.h header installed by ASan.

 * See https://github.com/google/sanitizers/wiki/AddressSanitizerManualPoisoning

 */

PL_ASAN_VISIBILITY(void) __asan_poison_memory_region(

    void const volatile *addr, size_t size);

PL_ASAN_VISIBILITY(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___ */