2 * Copyright (C) 2004-2009 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1997-2001 Internet Software Consortium.
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
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9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
18 /* $Id: mem.h,v 1.72.128.6 2009/02/11 03:09:55 jinmei Exp $ */
23 /*! \file isc/mem.h */
28 #include <isc/mutex.h>
29 #include <isc/platform.h>
30 #include <isc/types.h>
35 #define ISC_MEM_LOWATER 0
36 #define ISC_MEM_HIWATER 1
37 typedef void (*isc_mem_water_t)(void *, int);
39 typedef void * (*isc_memalloc_t)(void *, size_t);
40 typedef void (*isc_memfree_t)(void *, void *);
43 * Define ISC_MEM_DEBUG=1 to make all functions that free memory
44 * set the pointer being freed to NULL after being freed.
45 * This is the default; set ISC_MEM_DEBUG=0 to disable it.
48 #define ISC_MEM_DEBUG 1
52 * Define ISC_MEM_TRACKLINES=1 to turn on detailed tracing of memory
53 * allocation and freeing by file and line number.
55 #ifndef ISC_MEM_TRACKLINES
56 #define ISC_MEM_TRACKLINES 1
60 * Define ISC_MEM_CHECKOVERRUN=1 to turn on checks for using memory outside
61 * the requested space. This will increase the size of each allocation.
63 #ifndef ISC_MEM_CHECKOVERRUN
64 #define ISC_MEM_CHECKOVERRUN 1
68 * Define ISC_MEM_FILL=1 to fill each block of memory returned to the system
69 * with the byte string '0xbe'. This helps track down uninitialized pointers
70 * and the like. On freeing memory, the space is filled with '0xde' for
74 #define ISC_MEM_FILL 1
78 * Define ISC_MEMPOOL_NAMES=1 to make memory pools store a symbolic
79 * name so that the leaking pool can be more readily identified in
80 * case of a memory leak.
82 #ifndef ISC_MEMPOOL_NAMES
83 #define ISC_MEMPOOL_NAMES 1
86 LIBISC_EXTERNAL_DATA extern unsigned int isc_mem_debugging;
88 #define ISC_MEM_DEBUGTRACE 0x00000001U
89 #define ISC_MEM_DEBUGRECORD 0x00000002U
90 #define ISC_MEM_DEBUGUSAGE 0x00000004U
91 #define ISC_MEM_DEBUGSIZE 0x00000008U
92 #define ISC_MEM_DEBUGCTX 0x00000010U
93 #define ISC_MEM_DEBUGALL 0x0000001FU
95 * The variable isc_mem_debugging holds a set of flags for
96 * turning certain memory debugging options on or off at
97 * runtime. It is initialized to the value ISC_MEM_DEGBUGGING,
98 * which is 0 by default but may be overridden at compile time.
99 * The following flags can be specified:
101 * \li #ISC_MEM_DEBUGTRACE
102 * Log each allocation and free to isc_lctx.
104 * \li #ISC_MEM_DEBUGRECORD
105 * Remember each allocation, and match them up on free.
106 * Crash if a free doesn't match an allocation.
108 * \li #ISC_MEM_DEBUGUSAGE
109 * If a hi_water mark is set, print the maximum inuse memory
110 * every time it is raised once it exceeds the hi_water mark.
112 * \li #ISC_MEM_DEBUGSIZE
113 * Check the size argument being passed to isc_mem_put() matches
114 * that passed to isc_mem_get().
116 * \li #ISC_MEM_DEBUGCTX
117 * Check the mctx argument being passed to isc_mem_put() matches
118 * that passed to isc_mem_get().
122 #if ISC_MEM_TRACKLINES
123 #define _ISC_MEM_FILELINE , __FILE__, __LINE__
124 #define _ISC_MEM_FLARG , const char *, int
126 #define _ISC_MEM_FILELINE
127 #define _ISC_MEM_FLARG
131 * Define ISC_MEM_USE_INTERNAL_MALLOC=1 to use the internal malloc()
132 * implementation in preference to the system one. The internal malloc()
133 * is very space-efficient, and quite fast on uniprocessor systems. It
134 * performs poorly on multiprocessor machines.
135 * JT: we can overcome the performance issue on multiprocessor machines
136 * by carefully separating memory contexts.
139 #ifndef ISC_MEM_USE_INTERNAL_MALLOC
140 #define ISC_MEM_USE_INTERNAL_MALLOC 1
144 * Flags for isc_mem_create2()calls.
146 #define ISC_MEMFLAG_NOLOCK 0x00000001 /* no lock is necessary */
147 #define ISC_MEMFLAG_INTERNAL 0x00000002 /* use internal malloc */
148 #if ISC_MEM_USE_INTERNAL_MALLOC
149 #define ISC_MEMFLAG_DEFAULT ISC_MEMFLAG_INTERNAL
151 #define ISC_MEMFLAG_DEFAULT 0
155 #define isc_mem_get(c, s) isc__mem_get((c), (s) _ISC_MEM_FILELINE)
156 #define isc_mem_allocate(c, s) isc__mem_allocate((c), (s) _ISC_MEM_FILELINE)
157 #define isc_mem_reallocate(c, p, s) isc__mem_reallocate((c), (p), (s) _ISC_MEM_FILELINE)
158 #define isc_mem_strdup(c, p) isc__mem_strdup((c), (p) _ISC_MEM_FILELINE)
159 #define isc_mempool_get(c) isc__mempool_get((c) _ISC_MEM_FILELINE)
162 * isc_mem_putanddetach() is a convenience function for use where you
163 * have a structure with an attached memory context.
176 * isc_mem_putanddetach(&ptr->mctx, ptr, sizeof(*ptr));
179 * is the equivalent of:
183 * isc_mem_attach(ptr->mctx, &mctx);
184 * isc_mem_detach(&ptr->mctx);
185 * isc_mem_put(mctx, ptr, sizeof(*ptr));
186 * isc_mem_detach(&mctx);
191 #define isc_mem_put(c, p, s) \
193 isc__mem_put((c), (p), (s) _ISC_MEM_FILELINE); \
196 #define isc_mem_putanddetach(c, p, s) \
198 isc__mem_putanddetach((c), (p), (s) _ISC_MEM_FILELINE); \
201 #define isc_mem_free(c, p) \
203 isc__mem_free((c), (p) _ISC_MEM_FILELINE); \
206 #define isc_mempool_put(c, p) \
208 isc__mempool_put((c), (p) _ISC_MEM_FILELINE); \
212 #define isc_mem_put(c, p, s) isc__mem_put((c), (p), (s) _ISC_MEM_FILELINE)
213 #define isc_mem_putanddetach(c, p, s) \
214 isc__mem_putanddetach((c), (p), (s) _ISC_MEM_FILELINE)
215 #define isc_mem_free(c, p) isc__mem_free((c), (p) _ISC_MEM_FILELINE)
216 #define isc_mempool_put(c, p) isc__mempool_put((c), (p) _ISC_MEM_FILELINE)
221 isc_mem_create(size_t max_size, size_t target_size,
225 isc_mem_create2(size_t max_size, size_t target_size,
226 isc_mem_t **mctxp, unsigned int flags);
229 isc_mem_createx(size_t max_size, size_t target_size,
230 isc_memalloc_t memalloc, isc_memfree_t memfree,
231 void *arg, isc_mem_t **mctxp);
234 isc_mem_createx2(size_t max_size, size_t target_size,
235 isc_memalloc_t memalloc, isc_memfree_t memfree,
236 void *arg, isc_mem_t **mctxp, unsigned int flags);
239 * \brief Create a memory context.
241 * 'max_size' and 'target_size' are tuning parameters. When
242 * ISC_MEMFLAG_INTERNAL is set, allocations smaller than 'max_size'
243 * will be satisfied by getting blocks of size 'target_size' from the
244 * system allocator and breaking them up into pieces; larger allocations
245 * will use the system allocator directly. If 'max_size' and/or
246 * 'target_size' are zero, default values will be * used. When
247 * ISC_MEMFLAG_INTERNAL is not set, 'target_size' is ignored.
249 * 'max_size' is also used to size the statistics arrays and the array
250 * used to record active memory when ISC_MEM_DEBUGRECORD is set. Settin
251 * 'max_size' too low can have detrimental effects on performance.
253 * A memory context created using isc_mem_createx() will obtain
254 * memory from the system by calling 'memalloc' and 'memfree',
255 * passing them the argument 'arg'. A memory context created
256 * using isc_mem_create() will use the standard library malloc()
259 * If ISC_MEMFLAG_NOLOCK is set in 'flags', the corresponding memory context
260 * will be accessed without locking. The user who creates the context must
261 * ensure there be no race. Since this can be a source of bug, it is generally
262 * inadvisable to use this flag unless the user is very sure about the race
263 * condition and the access to the object is highly performance sensitive.
266 * mctxp != NULL && *mctxp == NULL */
271 isc_mem_attach(isc_mem_t *, isc_mem_t **);
273 isc_mem_detach(isc_mem_t **);
275 * \brief Attach to / detach from a memory context.
277 * This is intended for applications that use multiple memory contexts
278 * in such a way that it is not obvious when the last allocations from
279 * a given context has been freed and destroying the context is safe.
281 * Most applications do not need to call these functions as they can
282 * simply create a single memory context at the beginning of main()
283 * and destroy it at the end of main(), thereby guaranteeing that it
284 * is not destroyed while there are outstanding allocations.
289 isc_mem_destroy(isc_mem_t **);
291 * Destroy a memory context.
295 isc_mem_ondestroy(isc_mem_t *ctx,
297 isc_event_t **event);
299 * Request to be notified with an event when a memory context has
300 * been successfully destroyed.
304 isc_mem_stats(isc_mem_t *mctx, FILE *out);
306 * Print memory usage statistics for 'mctx' on the stream 'out'.
310 isc_mem_setdestroycheck(isc_mem_t *mctx,
313 * If 'on' is ISC_TRUE, 'mctx' will check for memory leaks when
314 * destroyed and abort the program if any are present.
319 isc_mem_setquota(isc_mem_t *, size_t);
321 isc_mem_getquota(isc_mem_t *);
323 * Set/get the memory quota of 'mctx'. This is a hard limit
324 * on the amount of memory that may be allocated from mctx;
325 * if it is exceeded, allocations will fail.
330 isc_mem_inuse(isc_mem_t *mctx);
332 * Get an estimate of the number of memory in use in 'mctx', in bytes.
333 * This includes quantization overhead, but does not include memory
334 * allocated from the system but not yet used.
338 isc_mem_setwater(isc_mem_t *mctx, isc_mem_water_t water, void *water_arg,
339 size_t hiwater, size_t lowater);
341 * Set high and low water marks for this memory context.
343 * When the memory usage of 'mctx' exceeds 'hiwater',
344 * '(water)(water_arg, #ISC_MEM_HIWATER)' will be called. 'water' needs to
345 * call isc_mem_waterack() with #ISC_MEM_HIWATER to acknowledge the state
346 * change. 'water' may be called multiple times.
348 * When the usage drops below 'lowater', 'water' will again be called, this
349 * time with #ISC_MEM_LOWATER. 'water' need to calls isc_mem_waterack() with
350 * #ISC_MEM_LOWATER to acknowledge the change.
353 * water(void *arg, int mark) {
354 * struct foo *foo = arg;
356 * LOCK(&foo->marklock);
357 * if (foo->mark != mark) {
360 * isc_mem_waterack(foo->mctx, mark);
362 * UNLOCK(&foo->marklock);
364 * If 'water' is NULL then 'water_arg', 'hi_water' and 'lo_water' are
365 * ignored and the state is reset.
369 * 'water' is not NULL.
370 * hi_water >= lo_water
374 isc_mem_waterack(isc_mem_t *ctx, int mark);
376 * Called to acknowledge changes in signaled by calls to 'water'.
380 isc_mem_printactive(isc_mem_t *mctx, FILE *file);
382 * Print to 'file' all active memory in 'mctx'.
384 * Requires ISC_MEM_DEBUGRECORD to have been set.
388 isc_mem_printallactive(FILE *file);
390 * Print to 'file' all active memory in all contexts.
392 * Requires ISC_MEM_DEBUGRECORD to have been set.
396 isc_mem_checkdestroyed(FILE *file);
398 * Check that all memory contexts have been destroyed.
399 * Prints out those that have not been.
400 * Fatally fails if there are still active contexts.
404 isc_mem_setname(isc_mem_t *ctx, const char *name, void *tag);
410 *\li Only the first 15 characters of 'name' will be copied.
412 *\li 'tag' is for debugging purposes only.
416 *\li 'ctx' is a valid ctx.
420 isc_mem_getname(isc_mem_t *ctx);
422 * Get the name of 'ctx', as previously set using isc_mem_setname().
425 *\li 'ctx' is a valid ctx.
428 *\li A non-NULL pointer to a null-terminated string.
429 * If the ctx has not been named, the string is
434 isc_mem_gettag(isc_mem_t *ctx);
436 * Get the tag value for 'task', as previously set using isc_mem_setname().
439 *\li 'ctx' is a valid ctx.
442 *\li This function is for debugging purposes only.
445 *\li 'ctx' is a valid task.
450 isc_mem_renderxml(xmlTextWriterPtr writer);
452 * Render all contexts' statistics and status in XML for writer.
454 #endif /* HAVE_LIBXML2 */
461 isc_mempool_create(isc_mem_t *mctx, size_t size, isc_mempool_t **mpctxp);
463 * Create a memory pool.
466 *\li mctx is a valid memory context.
468 *\li mpctxp != NULL and *mpctxp == NULL
471 *\li maxalloc = UINT_MAX
476 *\li #ISC_R_NOMEMORY -- not enough memory to create pool
477 *\li #ISC_R_SUCCESS -- all is well.
481 isc_mempool_destroy(isc_mempool_t **mpctxp);
483 * Destroy a memory pool.
486 *\li mpctxp != NULL && *mpctxp is a valid pool.
487 *\li The pool has no un"put" allocations outstanding
491 isc_mempool_setname(isc_mempool_t *mpctx, const char *name);
493 * Associate a name with a memory pool. At most 15 characters may be used.
496 *\li mpctx is a valid pool.
501 isc_mempool_associatelock(isc_mempool_t *mpctx, isc_mutex_t *lock);
503 * Associate a lock with this memory pool.
505 * This lock is used when getting or putting items using this memory pool,
506 * and it is also used to set or get internal state via the isc_mempool_get*()
507 * and isc_mempool_set*() set of functions.
509 * Multiple pools can each share a single lock. For instance, if "manager"
510 * type object contained pools for various sizes of events, and each of
511 * these pools used a common lock. Note that this lock must NEVER be used
512 * by other than mempool routines once it is given to a pool, since that can
513 * easily cause double locking.
517 *\li mpctpx is a valid pool.
521 *\li No previous lock is assigned to this pool.
523 *\li The lock is initialized before calling this function via the normal
524 * means of doing that.
528 * The following functions get/set various parameters. Note that due to
529 * the unlocked nature of pools these are potentially random values unless
530 * the imposed externally provided locking protocols are followed.
532 * Also note that the quota limits will not always take immediate effect.
533 * For instance, setting "maxalloc" to a number smaller than the currently
534 * allocated count is permitted. New allocations will be refused until
535 * the count drops below this threshold.
537 * All functions require (in addition to other requirements):
538 * mpctx is a valid memory pool
542 isc_mempool_getfreemax(isc_mempool_t *mpctx);
544 * Returns the maximum allowed size of the free list.
548 isc_mempool_setfreemax(isc_mempool_t *mpctx, unsigned int limit);
550 * Sets the maximum allowed size of the free list.
554 isc_mempool_getfreecount(isc_mempool_t *mpctx);
556 * Returns current size of the free list.
560 isc_mempool_getmaxalloc(isc_mempool_t *mpctx);
562 * Returns the maximum allowed number of allocations.
566 isc_mempool_setmaxalloc(isc_mempool_t *mpctx, unsigned int limit);
568 * Sets the maximum allowed number of allocations.
570 * Additional requirements:
575 isc_mempool_getallocated(isc_mempool_t *mpctx);
577 * Returns the number of items allocated from this pool.
581 isc_mempool_getfillcount(isc_mempool_t *mpctx);
583 * Returns the number of items allocated as a block from the parent memory
584 * context when the free list is empty.
588 isc_mempool_setfillcount(isc_mempool_t *mpctx, unsigned int limit);
590 * Sets the fillcount.
592 * Additional requirements:
598 * Pseudo-private functions for use via macros. Do not call directly.
601 isc__mem_get(isc_mem_t *, size_t _ISC_MEM_FLARG);
603 isc__mem_putanddetach(isc_mem_t **, void *,
604 size_t _ISC_MEM_FLARG);
606 isc__mem_put(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
608 isc__mem_allocate(isc_mem_t *, size_t _ISC_MEM_FLARG);
610 isc__mem_reallocate(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
612 isc__mem_free(isc_mem_t *, void * _ISC_MEM_FLARG);
614 isc__mem_strdup(isc_mem_t *, const char *_ISC_MEM_FLARG);
616 isc__mempool_get(isc_mempool_t * _ISC_MEM_FLARG);
618 isc__mempool_put(isc_mempool_t *, void * _ISC_MEM_FLARG);
622 #endif /* ISC_MEM_H */