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Diffstat (limited to 'mmalloc/mmprivate.h')
| -rw-r--r-- | mmalloc/mmprivate.h | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/mmalloc/mmprivate.h b/mmalloc/mmprivate.h new file mode 100644 index 0000000..f5e7555 --- /dev/null +++ b/mmalloc/mmprivate.h @@ -0,0 +1,352 @@ +/* Declarations for `mmalloc' and friends. + Copyright 1990, 1991, 1992 Free Software Foundation + + Written May 1989 by Mike Haertel. + Heavily modified Mar 1992 by Fred Fish. (fnf@cygnus.com) + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. + + The author may be reached (Email) at the address mike@ai.mit.edu, + or (US mail) as Mike Haertel c/o Free Software Foundation. */ + + +#ifndef __MMPRIVATE_H +#define __MMPRIVATE_H 1 + +#include "mmalloc.h" + +#ifdef __STDC__ +# include <limits.h> +# ifndef NULL +# define NULL (void *) 0 +# endif +#else +# ifndef size_t +# define size_t unsigned int +# endif +# ifndef CHAR_BIT +# define CHAR_BIT 8 +# endif +# ifndef NULL +# define NULL 0 +# endif +#endif + +#ifndef MIN +# define MIN(A, B) ((A) < (B) ? (A) : (B)) +#endif + +#define MMALLOC_MAGIC "mmalloc" /* Mapped file magic number */ +#define MMALLOC_MAGIC_SIZE 8 /* Size of magic number buf */ +#define MMALLOC_VERSION 1 /* Current mmalloc version */ +#define MMALLOC_KEYS 16 /* Keys for application use */ + +/* The allocator divides the heap into blocks of fixed size; large + requests receive one or more whole blocks, and small requests + receive a fragment of a block. Fragment sizes are powers of two, + and all fragments of a block are the same size. When all the + fragments in a block have been freed, the block itself is freed. */ + +#define INT_BIT (CHAR_BIT * sizeof(int)) +#define BLOCKLOG (INT_BIT > 16 ? 12 : 9) +#define BLOCKSIZE ((unsigned int) 1 << BLOCKLOG) +#define BLOCKIFY(SIZE) (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE) + +/* The difference between two pointers is a signed int. On machines where + the data addresses have the high bit set, we need to ensure that the + difference becomes an unsigned int when we are using the address as an + integral value. In addition, when using with the '%' operator, the + sign of the result is machine dependent for negative values, so force + it to be treated as an unsigned int. */ + +#define ADDR2UINT(addr) ((unsigned int) ((char *) (addr) - (char *) NULL)) +#define RESIDUAL(addr,bsize) ((unsigned int) (ADDR2UINT (addr) % (bsize))) + +/* Determine the amount of memory spanned by the initial heap table + (not an absolute limit). */ + +#define HEAP (INT_BIT > 16 ? 4194304 : 65536) + +/* Number of contiguous free blocks allowed to build up at the end of + memory before they will be returned to the system. */ + +#define FINAL_FREE_BLOCKS 8 + +/* Where to start searching the free list when looking for new memory. + The two possible values are 0 and heapindex. Starting at 0 seems + to reduce total memory usage, while starting at heapindex seems to + run faster. */ + +#define MALLOC_SEARCH_START mdp -> heapindex + +/* Address to block number and vice versa. */ + +#define BLOCK(A) (((char *) (A) - mdp -> heapbase) / BLOCKSIZE + 1) + +#define ADDRESS(B) ((PTR) (((B) - 1) * BLOCKSIZE + mdp -> heapbase)) + +/* Data structure giving per-block information. */ + +typedef union + { + /* Heap information for a busy block. */ + struct + { + /* Zero for a large block, or positive giving the + logarithm to the base two of the fragment size. */ + int type; + union + { + struct + { + size_t nfree; /* Free fragments in a fragmented block. */ + size_t first; /* First free fragment of the block. */ + } frag; + /* Size (in blocks) of a large cluster. */ + size_t size; + } info; + } busy; + /* Heap information for a free block (that may be the first of + a free cluster). */ + struct + { + size_t size; /* Size (in blocks) of a free cluster. */ + size_t next; /* Index of next free cluster. */ + size_t prev; /* Index of previous free cluster. */ + } free; + } malloc_info; + +/* List of blocks allocated with `mmemalign' (or `mvalloc'). */ + +struct alignlist + { + struct alignlist *next; + PTR aligned; /* The address that mmemaligned returned. */ + PTR exact; /* The address that malloc returned. */ + }; + +/* Doubly linked lists of free fragments. */ + +struct list + { + struct list *next; + struct list *prev; + }; + +/* Statistics available to the user. + FIXME: By design, the internals of the malloc package are no longer + exported to the user via an include file, so access to this data needs + to be via some other mechanism, such as mmstat_<something> where the + return value is the <something> the user is interested in. */ + +struct mstats + { + size_t bytes_total; /* Total size of the heap. */ + size_t chunks_used; /* Chunks allocated by the user. */ + size_t bytes_used; /* Byte total of user-allocated chunks. */ + size_t chunks_free; /* Chunks in the free list. */ + size_t bytes_free; /* Byte total of chunks in the free list. */ + }; + +/* Internal structure that defines the format of the malloc-descriptor. + This gets written to the base address of the region that mmalloc is + managing, and thus also becomes the file header for the mapped file, + if such a file exists. */ + +struct mdesc +{ + /* The "magic number" for an mmalloc file. */ + + char magic[MMALLOC_MAGIC_SIZE]; + + /* The size in bytes of this structure, used as a sanity check when reusing + a previously created mapped file. */ + + unsigned int headersize; + + /* The version number of the mmalloc package that created this file. */ + + unsigned char version; + + /* Some flag bits to keep track of various internal things. */ + + unsigned int flags; + + /* If a system call made by the mmalloc package fails, the errno is + preserved for future examination. */ + + int saved_errno; + + /* Pointer to the function that is used to get more core, or return core + to the system, for requests using this malloc descriptor. For memory + mapped regions, this is the mmap() based routine. There may also be + a single malloc descriptor that points to an sbrk() based routine + for systems without mmap() or for applications that call the mmalloc() + package with a NULL malloc descriptor. + + FIXME: For mapped regions shared by more than one process, this + needs to be maintained on a per-process basis. */ + + PTR (*morecore) PARAMS ((struct mdesc *, int)); + + /* Pointer to the function that causes an abort when the memory checking + features are activated. By default this is set to abort(), but can + be set to another function by the application using mmalloc(). + + FIXME: For mapped regions shared by more than one process, this + needs to be maintained on a per-process basis. */ + + void (*abortfunc) PARAMS ((void)); + + /* Debugging hook for free. + + FIXME: For mapped regions shared by more than one process, this + needs to be maintained on a per-process basis. */ + + void (*mfree_hook) PARAMS ((PTR, PTR)); + + /* Debugging hook for `malloc'. + + FIXME: For mapped regions shared by more than one process, this + needs to be maintained on a per-process basis. */ + + PTR (*mmalloc_hook) PARAMS ((PTR, size_t)); + + /* Debugging hook for realloc. + + FIXME: For mapped regions shared by more than one process, this + needs to be maintained on a per-process basis. */ + + PTR (*mrealloc_hook) PARAMS ((PTR, PTR, size_t)); + + /* Number of info entries. */ + + size_t heapsize; + + /* Pointer to first block of the heap (base of the first block). */ + + char *heapbase; + + /* Current search index for the heap table. */ + /* Search index in the info table. */ + + size_t heapindex; + + /* Limit of valid info table indices. */ + + size_t heaplimit; + + /* Block information table. + Allocated with malign/__mmalloc_free (not mmalloc/mfree). */ + /* Table indexed by block number giving per-block information. */ + + malloc_info *heapinfo; + + /* Instrumentation. */ + + struct mstats heapstats; + + /* Free list headers for each fragment size. */ + /* Free lists for each fragment size. */ + + struct list fraghead[BLOCKLOG]; + + /* List of blocks allocated by memalign. */ + + struct alignlist *aligned_blocks; + + /* The base address of the memory region for this malloc heap. This + is the location where the bookkeeping data for mmap and for malloc + begins. */ + + char *base; + + /* The current location in the memory region for this malloc heap which + represents the end of memory in use. */ + + char *breakval; + + /* The end of the current memory region for this malloc heap. This is + the first location past the end of mapped memory. */ + + char *top; + + /* Open file descriptor for the file to which this malloc heap is mapped. + This will always be a valid file descriptor, since /dev/zero is used + by default if no open file is supplied by the client. Also note that + it may change each time the region is mapped and unmapped. */ + + int fd; + + /* An array of keys to data within the mapped region, for use by the + application. */ + + PTR keys[MMALLOC_KEYS]; + +}; + +/* Bits to look at in the malloc descriptor flags word */ + +#define MMALLOC_DEVZERO (1 << 0) /* Have mapped to /dev/zero */ +#define MMALLOC_INITIALIZED (1 << 1) /* Initialized mmalloc */ +#define MMALLOC_MMCHECK_USED (1 << 2) /* mmcheck() called already */ + +/* Internal version of `mfree' used in `morecore'. */ + +extern void __mmalloc_free PARAMS ((struct mdesc *, PTR)); + +/* Hooks for debugging versions. */ + +extern void (*__mfree_hook) PARAMS ((PTR, PTR)); +extern PTR (*__mmalloc_hook) PARAMS ((PTR, size_t)); +extern PTR (*__mrealloc_hook) PARAMS ((PTR, PTR, size_t)); + +/* A default malloc descriptor for the single sbrk() managed region. */ + +extern struct mdesc *__mmalloc_default_mdp; + +/* Initialize the first use of the default malloc descriptor, which uses + an sbrk() region. */ + +extern struct mdesc *__mmalloc_sbrk_init PARAMS ((void)); + +/* Grow or shrink a contiguous mapped region using mmap(). + Works much like sbrk() */ + +#if defined(HAVE_MMAP) + +extern PTR __mmalloc_mmap_morecore PARAMS ((struct mdesc *, int)); + +#endif + +/* Remap a mmalloc region that was previously mapped. */ + +extern PTR __mmalloc_remap_core PARAMS ((struct mdesc *)); + +/* Macro to convert from a user supplied malloc descriptor to pointer to the + internal malloc descriptor. If the user supplied descriptor is NULL, then + use the default internal version, initializing it if necessary. Otherwise + just cast the user supplied version (which is void *) to the proper type + (struct mdesc *). */ + +#define MD_TO_MDP(md) \ + ((md) == NULL \ + ? (__mmalloc_default_mdp == NULL \ + ? __mmalloc_sbrk_init () \ + : __mmalloc_default_mdp) \ + : (struct mdesc *) (md)) + +#endif /* __MMPRIVATE_H */ |