Delete bundled copy of NSS and replace with README.

nspr/lib/ds/plarena.h

-/* -*- 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"
-#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
-};
-
-/*
- * 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
-
-#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___ */