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232 lines
6.7 KiB
C
232 lines
6.7 KiB
C
/* Declarations for `malloc' and friends.
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Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
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Written May 1989 by Mike Haertel.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with this library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 675 Mass Ave,
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Cambridge, MA 02139, USA.
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The author may be reached (Email) at the address mike@ai.mit.edu,
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or (US mail) as Mike Haertel c/o Free Software Foundation. */
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#ifndef _MALLOC_H
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#define _MALLOC_H 1
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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#if defined (__cplusplus) || (defined (__STDC__) && __STDC__)
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#undef __P
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#define __P(args) args
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#undef __ptr_t
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#define __ptr_t void *
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#else /* Not C++ or ANSI C. */
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#undef __P
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#define __P(args) ()
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#undef const
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#define const
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#undef __ptr_t
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#define __ptr_t char *
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#endif /* C++ or ANSI C. */
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#ifndef NULL
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#define NULL 0
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#endif
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#ifdef __STDC__
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#include <stddef.h>
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#else
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#undef size_t
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#define size_t unsigned int
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#undef ptrdiff_t
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#define ptrdiff_t int
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#endif
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/* Allocate SIZE bytes of memory. */
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extern __ptr_t malloc __P ((size_t __size));
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/* Re-allocate the previously allocated block
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in __ptr_t, making the new block SIZE bytes long. */
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extern __ptr_t realloc __P ((__ptr_t __ptr, size_t __size));
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/* Allocate NMEMB elements of SIZE bytes each, all initialized to 0. */
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extern __ptr_t calloc __P ((size_t __nmemb, size_t __size));
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/* Free a block allocated by `malloc', `realloc' or `calloc'. */
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extern void free __P ((__ptr_t __ptr));
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/* Allocate SIZE bytes allocated to ALIGNMENT bytes. */
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extern __ptr_t memalign __P ((size_t __alignment, size_t __size));
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/* Allocate SIZE bytes on a page boundary. */
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extern __ptr_t valloc __P ((size_t __size));
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#ifdef _MALLOC_INTERNAL
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#include <stdio.h> /* Harmless, gets __GNU_LIBRARY__ defined. */
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#if defined(__GNU_LIBRARY__) || defined(STDC_HEADERS) || defined(USG)
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#include <string.h>
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#else
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#ifndef memset
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#define memset(s, zero, n) bzero ((s), (n))
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#endif
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#ifndef memcpy
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#define memcpy(d, s, n) bcopy ((s), (d), (n))
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#endif
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#endif
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#if defined(__GNU_LIBRARY__) || defined(__STDC__)
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#include <limits.h>
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#else
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#define CHAR_BIT 8
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#endif
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/* The allocator divides the heap into blocks of fixed size; large
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requests receive one or more whole blocks, and small requests
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receive a fragment of a block. Fragment sizes are powers of two,
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and all fragments of a block are the same size. When all the
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fragments in a block have been freed, the block itself is freed. */
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#define INT_BIT (CHAR_BIT * sizeof(int))
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#define BLOCKLOG (INT_BIT > 16 ? 12 : 9)
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#define BLOCKSIZE (1 << BLOCKLOG)
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#define BLOCKIFY(SIZE) (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE)
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/* Determine the amount of memory spanned by the initial heap table
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(not an absolute limit). */
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#define HEAP (INT_BIT > 16 ? 4194304 : 65536)
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/* Number of contiguous free blocks allowed to build up at the end of
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memory before they will be returned to the system. */
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#define FINAL_FREE_BLOCKS 8
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/* Data structure giving per-block information. */
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typedef union
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{
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/* Heap information for a busy block. */
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struct
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{
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/* Zero for a large block, or positive giving the
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logarithm to the base two of the fragment size. */
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int type;
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union
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{
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struct
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{
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size_t nfree; /* Free fragments in a fragmented block. */
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size_t first; /* First free fragment of the block. */
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} frag;
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/* Size (in blocks) of a large cluster. */
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size_t size;
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} info;
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} busy;
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/* Heap information for a free block
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(that may be the first of a free cluster). */
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struct
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{
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size_t size; /* Size (in blocks) of a free cluster. */
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size_t next; /* Index of next free cluster. */
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size_t prev; /* Index of previous free cluster. */
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} free;
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} malloc_info;
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/* Pointer to first block of the heap. */
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extern char *_heapbase;
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/* Table indexed by block number giving per-block information. */
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extern malloc_info *_heapinfo;
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/* Address to block number and vice versa. */
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#define BLOCK(A) (((char *) (A) - _heapbase) / BLOCKSIZE + 1)
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#define ADDRESS(B) ((__ptr_t) (((B) - 1) * BLOCKSIZE + _heapbase))
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/* Current search index for the heap table. */
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extern size_t _heapindex;
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/* Limit of valid info table indices. */
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extern size_t _heaplimit;
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/* Doubly linked lists of free fragments. */
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struct list
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{
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struct list *next;
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struct list *prev;
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};
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/* Free list headers for each fragment size. */
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extern struct list _fraghead[];
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/* List of blocks allocated with `memalign' (or `valloc'). */
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struct alignlist
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{
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struct alignlist *next;
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__ptr_t aligned; /* The address that memaligned returned. */
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__ptr_t exact; /* The address that malloc returned. */
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};
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extern struct alignlist *_aligned_blocks;
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/* Instrumentation. */
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extern size_t _chunks_used;
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extern size_t _bytes_used;
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extern size_t _chunks_free;
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extern size_t _bytes_free;
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/* Internal version of `free' used in `morecore' (malloc.c). */
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extern void _free_internal __P ((__ptr_t __ptr));
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#endif /* _MALLOC_INTERNAL. */
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/* Underlying allocation function; successive calls should
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return contiguous pieces of memory. */
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extern __ptr_t (*__morecore) __P ((ptrdiff_t __size));
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/* Default value of `__morecore'. */
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extern __ptr_t __default_morecore __P ((ptrdiff_t __size));
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/* Nonzero if `malloc' has been called and done its initialization. */
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extern int __malloc_initialized;
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/* Hooks for debugging versions. */
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extern void (*__free_hook) __P ((__ptr_t __ptr));
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extern __ptr_t (*__malloc_hook) __P ((size_t __size));
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extern __ptr_t (*__realloc_hook) __P ((__ptr_t __ptr, size_t __size));
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/* Activate a standard collection of debugging hooks. */
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extern void mcheck __P ((void (*__func) __P ((void))));
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/* Activate a standard collection of tracing hooks. */
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extern void mtrace __P ((void));
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/* Statistics available to the user. */
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struct mstats
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{
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size_t bytes_total; /* Total size of the heap. */
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size_t chunks_used; /* Chunks allocated by the user. */
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size_t bytes_used; /* Byte total of user-allocated chunks. */
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size_t chunks_free; /* Chunks in the free list. */
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size_t bytes_free; /* Byte total of chunks in the free list. */
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};
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/* Pick up the current statistics. */
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extern struct mstats mstats __P ((void));
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#ifdef __cplusplus
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}
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#endif
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#endif /* malloc.h */
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