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
17 #include "xbt/xbt_os_thread.h"
18 #include "xbt/mmalloc.h"
29 # define MIN(A, B) ((A) < (B) ? (A) : (B))
32 #define MMALLOC_MAGIC "mmalloc" /* Mapped file magic number */
33 #define MMALLOC_MAGIC_SIZE 8 /* Size of magic number buf */
34 #define MMALLOC_VERSION 1 /* Current mmalloc version */
35 #define MMALLOC_KEYS 16 /* Keys for application use */
37 /* The allocator divides the heap into blocks of fixed size; large
38 requests receive one or more whole blocks, and small requests
39 receive a fragment of a block. Fragment sizes are powers of two,
40 and all fragments of a block are the same size. When all the
41 fragments in a block have been freed, the block itself is freed. */
43 #define INT_BIT (CHAR_BIT * sizeof(int))
44 #define BLOCKLOG (INT_BIT > 16 ? 12 : 9)
45 #define BLOCKSIZE ((unsigned int) 1 << BLOCKLOG)
46 #define BLOCKIFY(SIZE) (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE)
48 /* The difference between two pointers is a signed int. On machines where
49 the data addresses have the high bit set, we need to ensure that the
50 difference becomes an unsigned int when we are using the address as an
51 integral value. In addition, when using with the '%' operator, the
52 sign of the result is machine dependent for negative values, so force
53 it to be treated as an unsigned int. */
55 #define ADDR2UINT(addr) ((unsigned int) ((char*) (addr) - (char*) NULL))
56 #define RESIDUAL(addr,bsize) ((unsigned int) (ADDR2UINT (addr) % (bsize)))
58 /* Determine the amount of memory spanned by the initial heap table
59 (not an absolute limit). */
61 #define HEAP (INT_BIT > 16 ? 4194304 : 65536)
63 /* Number of contiguous free blocks allowed to build up at the end of
64 memory before they will be returned to the system. */
66 #define FINAL_FREE_BLOCKS 8
68 /* Where to start searching the free list when looking for new memory.
69 The two possible values are 0 and heapindex. Starting at 0 seems
70 to reduce total memory usage, while starting at heapindex seems to
73 #define MALLOC_SEARCH_START mdp -> heapindex
75 /* Address to block number and vice versa. */
77 #define BLOCK(A) (((char*) (A) - (char*) mdp -> heapbase) / BLOCKSIZE + 1)
79 #define ADDRESS(B) ((void*) (((ADDR2UINT(B)) - 1) * BLOCKSIZE + (char*) mdp -> heapbase))
81 /* Thread-safety (if the mutex is already created)*/
82 #define LOCK(mdp) if (mdp->mutex) xbt_os_mutex_acquire(mdp->mutex)
83 #define UNLOCK(mdp) if (mdp->mutex) xbt_os_mutex_release(mdp->mutex)
84 const char *xbt_thread_self_name(void);
86 /* Data structure giving per-block information. */
89 /* Heap information for a busy block. */
92 /* Zero for a large block, or positive giving the
93 logarithm to the base two of the fragment size. */
99 size_t nfree; /* Free fragments in a fragmented block. */
100 size_t first; /* First free fragment of the block. */
102 /* Size (in blocks) of a large cluster. */
106 /* Heap information for a free block (that may be the first of
110 size_t size; /* Size (in blocks) of a free cluster. */
111 size_t next; /* Index of next free cluster. */
112 size_t prev; /* Index of previous free cluster. */
116 /* List of blocks allocated with `mmemalign' (or `mvalloc'). */
120 struct alignlist *next;
121 void* aligned; /* The address that mmemaligned returned. */
122 void* exact; /* The address that malloc returned. */
125 /* Doubly linked lists of free fragments. */
133 /* Statistics available to the user.
134 FIXME: By design, the internals of the malloc package are no longer
135 exported to the user via an include file, so access to this data needs
136 to be via some other mechanism, such as mmstat_<something> where the
137 return value is the <something> the user is interested in. */
141 size_t bytes_total; /* Total size of the heap. */
142 size_t chunks_used; /* Chunks allocated by the user. */
143 size_t bytes_used; /* Byte total of user-allocated chunks. */
144 size_t chunks_free; /* Chunks in the free list. */
145 size_t bytes_free; /* Byte total of chunks in the free list. */
148 /* Internal structure that defines the format of the malloc-descriptor.
149 This gets written to the base address of the region that mmalloc is
150 managing, and thus also becomes the file header for the mapped file,
151 if such a file exists. */
154 xbt_os_mutex_t mutex;
155 /* The "magic number" for an mmalloc file. */
156 char magic[MMALLOC_MAGIC_SIZE];
158 /* The size in bytes of this structure, used as a sanity check when reusing
159 a previously created mapped file. */
160 unsigned int headersize;
162 /* The version number of the mmalloc package that created this file. */
163 unsigned char version;
165 /* Some flag bits to keep track of various internal things. */
168 /* If a system call made by the mmalloc package fails, the errno is
169 preserved for future examination. */
172 /* Pointer to the function that is used to get more core, or return core
173 to the system, for requests using this malloc descriptor. For memory
174 mapped regions, this is the mmap() based routine. There may also be
175 a single malloc descriptor that points to an sbrk() based routine
176 for systems without mmap() or for applications that call the mmalloc()
177 package with a NULL malloc descriptor.
179 FIXME: For mapped regions shared by more than one process, this
180 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. */
189 void (*abortfunc) (void);
191 /* Debugging hook for free.
193 FIXME: For mapped regions shared by more than one process, this
194 needs to be maintained on a per-process basis. */
195 void (*mfree_hook) (void* mdp, void* ptr);
197 /* Debugging hook for `malloc'.
199 FIXME: For mapped regions shared by more than one process, this
200 needs to be maintained on a per-process basis. */
201 void* (*mmalloc_hook) (void* mdp, size_t size);
203 /* Debugging hook for realloc.
205 FIXME: For mapped regions shared by more than one process, this
206 needs to be maintained on a per-process basis. */
207 void* (*mrealloc_hook) (void* mdp, void* ptr, size_t size);
209 /* Number of info entries. */
212 /* Pointer to first block of the heap (base of the first block). */
215 /* Current search index for the heap table. */
216 /* Search index in the info table. */
219 /* Limit of valid info table indices. */
222 /* Block information table.
223 Allocated with malign/__mmalloc_free (not mmalloc/mfree). */
224 /* Table indexed by block number giving per-block information. */
226 malloc_info *heapinfo;
228 /* Instrumentation. */
230 struct mstats heapstats;
232 /* Free list headers for each fragment size. */
233 /* Free lists for each fragment size. */
235 struct list fraghead[BLOCKLOG];
237 /* List of blocks allocated by memalign. */
239 struct alignlist *aligned_blocks;
241 /* The base address of the memory region for this malloc heap. This
242 is the location where the bookkeeping data for mmap and for malloc
247 /* The current location in the memory region for this malloc heap which
248 represents the end of memory in use. */
252 /* The end of the current memory region for this malloc heap. This is
253 the first location past the end of mapped memory. */
257 /* Open file descriptor for the file to which this malloc heap is mapped.
258 This will always be a valid file descriptor, since /dev/zero is used
259 by default if no open file is supplied by the client. Also note that
260 it may change each time the region is mapped and unmapped. */
264 /* An array of keys to data within the mapped region, for use by the
267 void* keys[MMALLOC_KEYS];
271 /* Bits to look at in the malloc descriptor flags word */
273 #define MMALLOC_DEVZERO (1 << 0) /* Have mapped to /dev/zero */
274 #define MMALLOC_ANONYMOUS (1 << 1) /* Use anonymous mapping */
275 #define MMALLOC_INITIALIZED (1 << 2) /* Initialized mmalloc */
276 #define MMALLOC_MMCHECK_USED (1 << 3) /* mmcheckf() called already */
278 /* Internal version of `mfree' used in `morecore'. */
280 extern void __mmalloc_free (struct mdesc *mdp, void* ptr);
282 /* A default malloc descriptor for the single sbrk() managed region. */
284 extern struct mdesc *__mmalloc_default_mdp;
286 /* Initialize the first use of the default malloc descriptor, which uses
289 extern struct mdesc *__mmalloc_create_default_mdp (void);
291 /* Grow or shrink a contiguous mapped region using mmap().
292 Works much like sbrk(), only faster */
294 extern void* __mmalloc_mmap_morecore (struct mdesc *mdp, int size);
297 /* Remap a mmalloc region that was previously mapped. */
299 extern void* __mmalloc_remap_core (struct mdesc *mdp);
301 /* Macro to convert from a user supplied malloc descriptor to pointer to the
302 internal malloc descriptor. If the user supplied descriptor is NULL, then
303 use the default internal version, initializing it if necessary. Otherwise
304 just cast the user supplied version (which is void *) to the proper type
307 #define MD_TO_MDP(md) \
309 ? __mmalloc_default_mdp \
310 : (struct mdesc *) (md))
312 #endif /* __MMPRIVATE_H */