1 /* Declarations for `mmalloc' and friends.
2 Copyright 1990, 1991, 1992 Free Software Foundation
4 Written May 1989 by Mike Haertel.
5 Heavily modified Mar 1992 by Fred Fish. (fnf@cygnus.com) */
7 /* Copyright (c) 2010. The SimGrid Team.
8 * All rights reserved. */
10 /* This program is free software; you can redistribute it and/or modify it
11 * under the terms of the license (GNU LGPL) which comes with this package. */
14 #define __MMPRIVATE_H 1
16 #include "xbt/mmalloc.h"
27 # define MIN(A, B) ((A) < (B) ? (A) : (B))
30 #define MMALLOC_MAGIC "mmalloc" /* Mapped file magic number */
31 #define MMALLOC_MAGIC_SIZE 8 /* Size of magic number buf */
32 #define MMALLOC_VERSION 1 /* Current mmalloc version */
33 #define MMALLOC_KEYS 16 /* Keys for application use */
35 /* The allocator divides the heap into blocks of fixed size; large
36 requests receive one or more whole blocks, and small requests
37 receive a fragment of a block. Fragment sizes are powers of two,
38 and all fragments of a block are the same size. When all the
39 fragments in a block have been freed, the block itself is freed. */
41 #define INT_BIT (CHAR_BIT * sizeof(int))
42 #define BLOCKLOG (INT_BIT > 16 ? 12 : 9)
43 #define BLOCKSIZE ((unsigned int) 1 << BLOCKLOG)
44 #define BLOCKIFY(SIZE) (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE)
46 /* The difference between two pointers is a signed int. On machines where
47 the data addresses have the high bit set, we need to ensure that the
48 difference becomes an unsigned int when we are using the address as an
49 integral value. In addition, when using with the '%' operator, the
50 sign of the result is machine dependent for negative values, so force
51 it to be treated as an unsigned int. */
53 #define ADDR2UINT(addr) ((unsigned int) ((char*) (addr) - (char*) NULL))
54 #define RESIDUAL(addr,bsize) ((unsigned int) (ADDR2UINT (addr) % (bsize)))
56 /* Determine the amount of memory spanned by the initial heap table
57 (not an absolute limit). */
59 #define HEAP (INT_BIT > 16 ? 4194304 : 65536)
61 /* Number of contiguous free blocks allowed to build up at the end of
62 memory before they will be returned to the system. */
64 #define FINAL_FREE_BLOCKS 8
66 /* Where to start searching the free list when looking for new memory.
67 The two possible values are 0 and heapindex. Starting at 0 seems
68 to reduce total memory usage, while starting at heapindex seems to
71 #define MALLOC_SEARCH_START mdp -> heapindex
73 /* Address to block number and vice versa. */
75 #define BLOCK(A) (((char*) (A) - (char*) mdp -> heapbase) / BLOCKSIZE + 1)
77 #define ADDRESS(B) ((void*) (((ADDR2UINT(B)) - 1) * BLOCKSIZE + (char*) mdp -> heapbase))
79 /* Data structure giving per-block information. */
83 /* Heap information for a busy block. */
86 /* Zero for a large block, or positive giving the
87 logarithm to the base two of the fragment size. */
93 size_t nfree; /* Free fragments in a fragmented block. */
94 size_t first; /* First free fragment of the block. */
96 /* Size (in blocks) of a large cluster. */
100 /* Heap information for a free block (that may be the first of
104 size_t size; /* Size (in blocks) of a free cluster. */
105 size_t next; /* Index of next free cluster. */
106 size_t prev; /* Index of previous free cluster. */
110 /* List of blocks allocated with `mmemalign' (or `mvalloc'). */
114 struct alignlist *next;
115 void* aligned; /* The address that mmemaligned returned. */
116 void* exact; /* The address that malloc returned. */
119 /* Doubly linked lists of free fragments. */
127 /* Statistics available to the user.
128 FIXME: By design, the internals of the malloc package are no longer
129 exported to the user via an include file, so access to this data needs
130 to be via some other mechanism, such as mmstat_<something> where the
131 return value is the <something> the user is interested in. */
135 size_t bytes_total; /* Total size of the heap. */
136 size_t chunks_used; /* Chunks allocated by the user. */
137 size_t bytes_used; /* Byte total of user-allocated chunks. */
138 size_t chunks_free; /* Chunks in the free list. */
139 size_t bytes_free; /* Byte total of chunks in the free list. */
142 /* Internal structure that defines the format of the malloc-descriptor.
143 This gets written to the base address of the region that mmalloc is
144 managing, and thus also becomes the file header for the mapped file,
145 if such a file exists. */
149 /* The "magic number" for an mmalloc file. */
151 char magic[MMALLOC_MAGIC_SIZE];
153 /* The size in bytes of this structure, used as a sanity check when reusing
154 a previously created mapped file. */
156 unsigned int headersize;
158 /* The version number of the mmalloc package that created this file. */
160 unsigned char version;
162 /* Some flag bits to keep track of various internal things. */
166 /* If a system call made by the mmalloc package fails, the errno is
167 preserved for future examination. */
171 /* Pointer to the function that is used to get more core, or return core
172 to the system, for requests using this malloc descriptor. For memory
173 mapped regions, this is the mmap() based routine. There may also be
174 a single malloc descriptor that points to an sbrk() based routine
175 for systems without mmap() or for applications that call the mmalloc()
176 package with a NULL malloc descriptor.
178 FIXME: For mapped regions shared by more than one process, this
179 needs to be maintained on a per-process basis. */
181 void* (*morecore) (struct mdesc *mdp, int size);
183 /* Pointer to the function that causes an abort when the memory checking
184 features are activated. By default this is set to abort(), but can
185 be set to another function by the application using mmalloc().
187 FIXME: For mapped regions shared by more than one process, this
188 needs to be maintained on a per-process basis. */
190 void (*abortfunc) (void);
192 /* Debugging hook for free.
194 FIXME: For mapped regions shared by more than one process, this
195 needs to be maintained on a per-process basis. */
197 void (*mfree_hook) (void* mdp, void* ptr);
199 /* Debugging hook for `malloc'.
201 FIXME: For mapped regions shared by more than one process, this
202 needs to be maintained on a per-process basis. */
204 void* (*mmalloc_hook) (void* mdp, size_t size);
206 /* Debugging hook for realloc.
208 FIXME: For mapped regions shared by more than one process, this
209 needs to be maintained on a per-process basis. */
211 void* (*mrealloc_hook) (void* mdp, void* ptr, size_t size);
213 /* Number of info entries. */
217 /* Pointer to first block of the heap (base of the first block). */
221 /* Current search index for the heap table. */
222 /* Search index in the info table. */
226 /* Limit of valid info table indices. */
230 /* Block information table.
231 Allocated with malign/__mmalloc_free (not mmalloc/mfree). */
232 /* Table indexed by block number giving per-block information. */
234 malloc_info *heapinfo;
236 /* Instrumentation. */
238 struct mstats heapstats;
240 /* Free list headers for each fragment size. */
241 /* Free lists for each fragment size. */
243 struct list fraghead[BLOCKLOG];
245 /* List of blocks allocated by memalign. */
247 struct alignlist *aligned_blocks;
249 /* The base address of the memory region for this malloc heap. This
250 is the location where the bookkeeping data for mmap and for malloc
255 /* The current location in the memory region for this malloc heap which
256 represents the end of memory in use. */
260 /* The end of the current memory region for this malloc heap. This is
261 the first location past the end of mapped memory. */
265 /* Open file descriptor for the file to which this malloc heap is mapped.
266 This will always be a valid file descriptor, since /dev/zero is used
267 by default if no open file is supplied by the client. Also note that
268 it may change each time the region is mapped and unmapped. */
272 /* An array of keys to data within the mapped region, for use by the
275 void* keys[MMALLOC_KEYS];
279 /* Bits to look at in the malloc descriptor flags word */
281 #define MMALLOC_DEVZERO (1 << 0) /* Have mapped to /dev/zero */
282 #define MMALLOC_ANONYMOUS (1 << 1) /* Use anonymous mapping */
283 #define MMALLOC_INITIALIZED (1 << 2) /* Initialized mmalloc */
284 #define MMALLOC_MMCHECK_USED (1 << 3) /* mmcheckf() called already */
286 /* Internal version of `mfree' used in `morecore'. */
288 extern void __mmalloc_free (struct mdesc *mdp, void* ptr);
290 /* A default malloc descriptor for the single sbrk() managed region. */
292 extern struct mdesc *__mmalloc_default_mdp;
294 /* Initialize the first use of the default malloc descriptor, which uses
297 extern struct mdesc *__mmalloc_sbrk_init (void);
299 /* Grow or shrink a contiguous mapped region using mmap().
300 Works much like sbrk() */
302 #if defined(HAVE_MMAP)
304 extern void* __mmalloc_mmap_morecore (struct mdesc *mdp, int size);
308 /* Remap a mmalloc region that was previously mapped. */
310 extern void* __mmalloc_remap_core (struct mdesc *mdp);
312 /* Macro to convert from a user supplied malloc descriptor to pointer to the
313 internal malloc descriptor. If the user supplied descriptor is NULL, then
314 use the default internal version, initializing it if necessary. Otherwise
315 just cast the user supplied version (which is void *) to the proper type
318 #define MD_TO_MDP(md) \
320 ? (__mmalloc_default_mdp == NULL \
321 ? __mmalloc_sbrk_init () \
322 : __mmalloc_default_mdp) \
323 : (struct mdesc *) (md))
325 #endif /* __MMPRIVATE_H */