2 * Copyright (C) 2004-2012, 2015 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
7 * copyright notice and this permission notice appear in all copies.
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.
21 /*! \file isc/mem.h */
26 #include <isc/mutex.h>
27 #include <isc/platform.h>
28 #include <isc/types.h>
33 #define ISC_MEM_LOWATER 0
34 #define ISC_MEM_HIWATER 1
35 typedef void (*isc_mem_water_t)(void *, int);
37 typedef void * (*isc_memalloc_t)(void *, size_t);
38 typedef void (*isc_memfree_t)(void *, void *);
41 * Define ISC_MEM_TRACKLINES=1 to turn on detailed tracing of memory
42 * allocation and freeing by file and line number.
44 #ifndef ISC_MEM_TRACKLINES
45 #define ISC_MEM_TRACKLINES 1
49 * Define ISC_MEM_CHECKOVERRUN=1 to turn on checks for using memory outside
50 * the requested space. This will increase the size of each allocation.
52 * If we are performing a Coverity static analysis then ISC_MEM_CHECKOVERRUN
53 * can hide bugs that would otherwise discovered so force to zero.
56 #undef ISC_MEM_CHECKOVERRUN
57 #define ISC_MEM_CHECKOVERRUN 0
59 #ifndef ISC_MEM_CHECKOVERRUN
60 #define ISC_MEM_CHECKOVERRUN 1
64 * Define ISC_MEM_FILL=1 to fill each block of memory returned to the system
65 * with the byte string '0xbe'. This helps track down uninitialized pointers
66 * and the like. On freeing memory, the space is filled with '0xde' for
69 * If we are performing a Coverity static analysis then ISC_MEM_FILL
70 * can hide bugs that would otherwise discovered so force to zero.
74 #define ISC_MEM_FILL 0
77 #define ISC_MEM_FILL 1
81 * Define ISC_MEMPOOL_NAMES=1 to make memory pools store a symbolic
82 * name so that the leaking pool can be more readily identified in
83 * case of a memory leak.
85 #ifndef ISC_MEMPOOL_NAMES
86 #define ISC_MEMPOOL_NAMES 1
89 LIBISC_EXTERNAL_DATA extern unsigned int isc_mem_debugging;
90 LIBISC_EXTERNAL_DATA extern unsigned int isc_mem_defaultflags;
93 #define ISC_MEM_DEBUGTRACE 0x00000001U
94 #define ISC_MEM_DEBUGRECORD 0x00000002U
95 #define ISC_MEM_DEBUGUSAGE 0x00000004U
96 #define ISC_MEM_DEBUGSIZE 0x00000008U
97 #define ISC_MEM_DEBUGCTX 0x00000010U
98 #define ISC_MEM_DEBUGALL 0x0000001FU
100 * The variable isc_mem_debugging holds a set of flags for
101 * turning certain memory debugging options on or off at
102 * runtime. It is initialized to the value ISC_MEM_DEGBUGGING,
103 * which is 0 by default but may be overridden at compile time.
104 * The following flags can be specified:
106 * \li #ISC_MEM_DEBUGTRACE
107 * Log each allocation and free to isc_lctx.
109 * \li #ISC_MEM_DEBUGRECORD
110 * Remember each allocation, and match them up on free.
111 * Crash if a free doesn't match an allocation.
113 * \li #ISC_MEM_DEBUGUSAGE
114 * If a hi_water mark is set, print the maximum inuse memory
115 * every time it is raised once it exceeds the hi_water mark.
117 * \li #ISC_MEM_DEBUGSIZE
118 * Check the size argument being passed to isc_mem_put() matches
119 * that passed to isc_mem_get().
121 * \li #ISC_MEM_DEBUGCTX
122 * Check the mctx argument being passed to isc_mem_put() matches
123 * that passed to isc_mem_get().
127 #if ISC_MEM_TRACKLINES
128 #define _ISC_MEM_FILELINE , __FILE__, __LINE__
129 #define _ISC_MEM_FLARG , const char *, unsigned int
131 #define _ISC_MEM_FILELINE
132 #define _ISC_MEM_FLARG
136 * Define ISC_MEM_USE_INTERNAL_MALLOC=1 to use the internal malloc()
137 * implementation in preference to the system one. The internal malloc()
138 * is very space-efficient, and quite fast on uniprocessor systems. It
139 * performs poorly on multiprocessor machines.
140 * JT: we can overcome the performance issue on multiprocessor machines
141 * by carefully separating memory contexts.
144 #ifndef ISC_MEM_USE_INTERNAL_MALLOC
145 #define ISC_MEM_USE_INTERNAL_MALLOC 1
149 * Flags for isc_mem_create2()calls.
151 #define ISC_MEMFLAG_NOLOCK 0x00000001 /* no lock is necessary */
152 #define ISC_MEMFLAG_INTERNAL 0x00000002 /* use internal malloc */
153 #if ISC_MEM_USE_INTERNAL_MALLOC
154 #define ISC_MEMFLAG_DEFAULT ISC_MEMFLAG_INTERNAL
156 #define ISC_MEMFLAG_DEFAULT 0
161 * We use either isc___mem (three underscores) or isc__mem (two) depending on
162 * whether it's for BIND9's internal purpose (with -DBIND9) or generic export
163 * library. This condition is generally handled in isc/namespace.h, but for
164 * Windows it doesn't work if it involves multiple times of macro expansion
165 * (such as isc_mem to isc__mem then to isc___mem). The following definitions
166 * are used to work around this portability issue. Right now, we don't support
167 * the export library for Windows, so we always use the three-underscore
171 #define ISCMEMFUNC(sfx) isc___mem_ ## sfx
172 #define ISCMEMPOOLFUNC(sfx) isc___mempool_ ## sfx
174 #define ISCMEMFUNC(sfx) isc__mem_ ## sfx
175 #define ISCMEMPOOLFUNC(sfx) isc__mempool_ ## sfx
178 #define isc_mem_get(c, s) ISCMEMFUNC(get)((c), (s) _ISC_MEM_FILELINE)
179 #define isc_mem_allocate(c, s) ISCMEMFUNC(allocate)((c), (s) _ISC_MEM_FILELINE)
180 #define isc_mem_reallocate(c, p, s) ISCMEMFUNC(reallocate)((c), (p), (s) _ISC_MEM_FILELINE)
181 #define isc_mem_strdup(c, p) ISCMEMFUNC(strdup)((c), (p) _ISC_MEM_FILELINE)
182 #define isc_mempool_get(c) ISCMEMPOOLFUNC(get)((c) _ISC_MEM_FILELINE)
185 * isc_mem_putanddetach() is a convenience function for use where you
186 * have a structure with an attached memory context.
199 * isc_mem_putanddetach(&ptr->mctx, ptr, sizeof(*ptr));
202 * is the equivalent of:
206 * isc_mem_attach(ptr->mctx, &mctx);
207 * isc_mem_detach(&ptr->mctx);
208 * isc_mem_put(mctx, ptr, sizeof(*ptr));
209 * isc_mem_detach(&mctx);
213 /*% memory and memory pool methods */
214 typedef struct isc_memmethods {
215 void (*attach)(isc_mem_t *source, isc_mem_t **targetp);
216 void (*detach)(isc_mem_t **mctxp);
217 void (*destroy)(isc_mem_t **mctxp);
218 void *(*memget)(isc_mem_t *mctx, size_t size _ISC_MEM_FLARG);
219 void (*memput)(isc_mem_t *mctx, void *ptr, size_t size _ISC_MEM_FLARG);
220 void (*memputanddetach)(isc_mem_t **mctxp, void *ptr,
221 size_t size _ISC_MEM_FLARG);
222 void *(*memallocate)(isc_mem_t *mctx, size_t size _ISC_MEM_FLARG);
223 void *(*memreallocate)(isc_mem_t *mctx, void *ptr,
224 size_t size _ISC_MEM_FLARG);
225 char *(*memstrdup)(isc_mem_t *mctx, const char *s _ISC_MEM_FLARG);
226 void (*memfree)(isc_mem_t *mctx, void *ptr _ISC_MEM_FLARG);
227 void (*setdestroycheck)(isc_mem_t *mctx, isc_boolean_t flag);
228 void (*setwater)(isc_mem_t *ctx, isc_mem_water_t water,
229 void *water_arg, size_t hiwater, size_t lowater);
230 void (*waterack)(isc_mem_t *ctx, int flag);
231 size_t (*inuse)(isc_mem_t *mctx);
232 isc_boolean_t (*isovermem)(isc_mem_t *mctx);
233 isc_result_t (*mpcreate)(isc_mem_t *mctx, size_t size,
234 isc_mempool_t **mpctxp);
237 typedef struct isc_mempoolmethods {
238 void (*destroy)(isc_mempool_t **mpctxp);
239 void *(*get)(isc_mempool_t *mpctx _ISC_MEM_FLARG);
240 void (*put)(isc_mempool_t *mpctx, void *mem _ISC_MEM_FLARG);
241 unsigned int (*getallocated)(isc_mempool_t *mpctx);
242 void (*setmaxalloc)(isc_mempool_t *mpctx, unsigned int limit);
243 void (*setfreemax)(isc_mempool_t *mpctx, unsigned int limit);
244 void (*setname)(isc_mempool_t *mpctx, const char *name);
245 void (*associatelock)(isc_mempool_t *mpctx, isc_mutex_t *lock);
246 void (*setfillcount)(isc_mempool_t *mpctx, unsigned int limit);
247 } isc_mempoolmethods_t;
250 * This structure is actually just the common prefix of a memory context
251 * implementation's version of an isc_mem_t.
253 * Direct use of this structure by clients is forbidden. mctx implementations
254 * may change the structure. 'magic' must be ISCAPI_MCTX_MAGIC for any of the
255 * isc_mem_ routines to work. mctx implementations must maintain all mctx
259 unsigned int impmagic;
261 isc_memmethods_t *methods;
264 #define ISCAPI_MCTX_MAGIC ISC_MAGIC('A','m','c','x')
265 #define ISCAPI_MCTX_VALID(m) ((m) != NULL && \
266 (m)->magic == ISCAPI_MCTX_MAGIC)
269 * This is the common prefix of a memory pool context. The same note as
270 * that for the mem structure applies.
273 unsigned int impmagic;
275 isc_mempoolmethods_t *methods;
278 #define ISCAPI_MPOOL_MAGIC ISC_MAGIC('A','m','p','l')
279 #define ISCAPI_MPOOL_VALID(mp) ((mp) != NULL && \
280 (mp)->magic == ISCAPI_MPOOL_MAGIC)
282 #define isc_mem_put(c, p, s) \
284 ISCMEMFUNC(put)((c), (p), (s) _ISC_MEM_FILELINE); \
287 #define isc_mem_putanddetach(c, p, s) \
289 ISCMEMFUNC(putanddetach)((c), (p), (s) _ISC_MEM_FILELINE); \
292 #define isc_mem_free(c, p) \
294 ISCMEMFUNC(free)((c), (p) _ISC_MEM_FILELINE); \
297 #define isc_mempool_put(c, p) \
299 ISCMEMPOOLFUNC(put)((c), (p) _ISC_MEM_FILELINE); \
305 isc_mem_create(size_t max_size, size_t target_size,
309 isc_mem_create2(size_t max_size, size_t target_size,
310 isc_mem_t **mctxp, unsigned int flags);
313 isc_mem_createx(size_t max_size, size_t target_size,
314 isc_memalloc_t memalloc, isc_memfree_t memfree,
315 void *arg, isc_mem_t **mctxp);
318 isc_mem_createx2(size_t max_size, size_t target_size,
319 isc_memalloc_t memalloc, isc_memfree_t memfree,
320 void *arg, isc_mem_t **mctxp, unsigned int flags);
323 * \brief Create a memory context.
325 * 'max_size' and 'target_size' are tuning parameters. When
326 * ISC_MEMFLAG_INTERNAL is set, allocations smaller than 'max_size'
327 * will be satisfied by getting blocks of size 'target_size' from the
328 * system allocator and breaking them up into pieces; larger allocations
329 * will use the system allocator directly. If 'max_size' and/or
330 * 'target_size' are zero, default values will be * used. When
331 * ISC_MEMFLAG_INTERNAL is not set, 'target_size' is ignored.
333 * 'max_size' is also used to size the statistics arrays and the array
334 * used to record active memory when ISC_MEM_DEBUGRECORD is set. Setting
335 * 'max_size' too low can have detrimental effects on performance.
337 * A memory context created using isc_mem_createx() will obtain
338 * memory from the system by calling 'memalloc' and 'memfree',
339 * passing them the argument 'arg'. A memory context created
340 * using isc_mem_create() will use the standard library malloc()
343 * If ISC_MEMFLAG_NOLOCK is set in 'flags', the corresponding memory context
344 * will be accessed without locking. The user who creates the context must
345 * ensure there be no race. Since this can be a source of bug, it is generally
346 * inadvisable to use this flag unless the user is very sure about the race
347 * condition and the access to the object is highly performance sensitive.
350 * mctxp != NULL && *mctxp == NULL */
355 isc_mem_attach(isc_mem_t *, isc_mem_t **);
357 isc_mem_detach(isc_mem_t **);
359 * \brief Attach to / detach from a memory context.
361 * This is intended for applications that use multiple memory contexts
362 * in such a way that it is not obvious when the last allocations from
363 * a given context has been freed and destroying the context is safe.
365 * Most applications do not need to call these functions as they can
366 * simply create a single memory context at the beginning of main()
367 * and destroy it at the end of main(), thereby guaranteeing that it
368 * is not destroyed while there are outstanding allocations.
373 isc_mem_destroy(isc_mem_t **);
375 * Destroy a memory context.
379 isc_mem_ondestroy(isc_mem_t *ctx,
381 isc_event_t **event);
383 * Request to be notified with an event when a memory context has
384 * been successfully destroyed.
388 isc_mem_stats(isc_mem_t *mctx, FILE *out);
390 * Print memory usage statistics for 'mctx' on the stream 'out'.
394 isc_mem_setdestroycheck(isc_mem_t *mctx,
397 * If 'on' is ISC_TRUE, 'mctx' will check for memory leaks when
398 * destroyed and abort the program if any are present.
403 isc_mem_setquota(isc_mem_t *, size_t);
405 isc_mem_getquota(isc_mem_t *);
407 * Set/get the memory quota of 'mctx'. This is a hard limit
408 * on the amount of memory that may be allocated from mctx;
409 * if it is exceeded, allocations will fail.
414 isc_mem_inuse(isc_mem_t *mctx);
416 * Get an estimate of the number of memory in use in 'mctx', in bytes.
417 * This includes quantization overhead, but does not include memory
418 * allocated from the system but not yet used.
422 isc_mem_isovermem(isc_mem_t *mctx);
424 * Return true iff the memory context is in "over memory" state, i.e.,
425 * a hiwater mark has been set and the used amount of memory has exceeds
430 isc_mem_setwater(isc_mem_t *mctx, isc_mem_water_t water, void *water_arg,
431 size_t hiwater, size_t lowater);
433 * Set high and low water marks for this memory context.
435 * When the memory usage of 'mctx' exceeds 'hiwater',
436 * '(water)(water_arg, #ISC_MEM_HIWATER)' will be called. 'water' needs to
437 * call isc_mem_waterack() with #ISC_MEM_HIWATER to acknowledge the state
438 * change. 'water' may be called multiple times.
440 * When the usage drops below 'lowater', 'water' will again be called, this
441 * time with #ISC_MEM_LOWATER. 'water' need to calls isc_mem_waterack() with
442 * #ISC_MEM_LOWATER to acknowledge the change.
445 * water(void *arg, int mark) {
446 * struct foo *foo = arg;
448 * LOCK(&foo->marklock);
449 * if (foo->mark != mark) {
452 * isc_mem_waterack(foo->mctx, mark);
454 * UNLOCK(&foo->marklock);
457 * If 'water' is NULL then 'water_arg', 'hi_water' and 'lo_water' are
458 * ignored and the state is reset.
462 * 'water' is not NULL.
463 * hi_water >= lo_water
467 isc_mem_waterack(isc_mem_t *ctx, int mark);
469 * Called to acknowledge changes in signaled by calls to 'water'.
473 isc_mem_printactive(isc_mem_t *mctx, FILE *file);
475 * Print to 'file' all active memory in 'mctx'.
477 * Requires ISC_MEM_DEBUGRECORD to have been set.
481 isc_mem_printallactive(FILE *file);
483 * Print to 'file' all active memory in all contexts.
485 * Requires ISC_MEM_DEBUGRECORD to have been set.
489 isc_mem_checkdestroyed(FILE *file);
491 * Check that all memory contexts have been destroyed.
492 * Prints out those that have not been.
493 * Fatally fails if there are still active contexts.
497 isc_mem_references(isc_mem_t *ctx);
499 * Return the current reference count.
503 isc_mem_setname(isc_mem_t *ctx, const char *name, void *tag);
509 *\li Only the first 15 characters of 'name' will be copied.
511 *\li 'tag' is for debugging purposes only.
515 *\li 'ctx' is a valid ctx.
519 isc_mem_getname(isc_mem_t *ctx);
521 * Get the name of 'ctx', as previously set using isc_mem_setname().
524 *\li 'ctx' is a valid ctx.
527 *\li A non-NULL pointer to a null-terminated string.
528 * If the ctx has not been named, the string is
533 isc_mem_gettag(isc_mem_t *ctx);
535 * Get the tag value for 'task', as previously set using isc_mem_setname().
538 *\li 'ctx' is a valid ctx.
541 *\li This function is for debugging purposes only.
544 *\li 'ctx' is a valid task.
549 isc_mem_renderxml(xmlTextWriterPtr writer);
551 * Render all contexts' statistics and status in XML for writer.
553 #endif /* HAVE_LIBXML2 */
560 isc_mempool_create(isc_mem_t *mctx, size_t size, isc_mempool_t **mpctxp);
562 * Create a memory pool.
565 *\li mctx is a valid memory context.
567 *\li mpctxp != NULL and *mpctxp == NULL
570 *\li maxalloc = UINT_MAX
575 *\li #ISC_R_NOMEMORY -- not enough memory to create pool
576 *\li #ISC_R_SUCCESS -- all is well.
580 isc_mempool_destroy(isc_mempool_t **mpctxp);
582 * Destroy a memory pool.
585 *\li mpctxp != NULL && *mpctxp is a valid pool.
586 *\li The pool has no un"put" allocations outstanding
590 isc_mempool_setname(isc_mempool_t *mpctx, const char *name);
592 * Associate a name with a memory pool. At most 15 characters may be used.
595 *\li mpctx is a valid pool.
600 isc_mempool_associatelock(isc_mempool_t *mpctx, isc_mutex_t *lock);
602 * Associate a lock with this memory pool.
604 * This lock is used when getting or putting items using this memory pool,
605 * and it is also used to set or get internal state via the isc_mempool_get*()
606 * and isc_mempool_set*() set of functions.
608 * Multiple pools can each share a single lock. For instance, if "manager"
609 * type object contained pools for various sizes of events, and each of
610 * these pools used a common lock. Note that this lock must NEVER be used
611 * by other than mempool routines once it is given to a pool, since that can
612 * easily cause double locking.
616 *\li mpctpx is a valid pool.
620 *\li No previous lock is assigned to this pool.
622 *\li The lock is initialized before calling this function via the normal
623 * means of doing that.
627 * The following functions get/set various parameters. Note that due to
628 * the unlocked nature of pools these are potentially random values unless
629 * the imposed externally provided locking protocols are followed.
631 * Also note that the quota limits will not always take immediate effect.
632 * For instance, setting "maxalloc" to a number smaller than the currently
633 * allocated count is permitted. New allocations will be refused until
634 * the count drops below this threshold.
636 * All functions require (in addition to other requirements):
637 * mpctx is a valid memory pool
641 isc_mempool_getfreemax(isc_mempool_t *mpctx);
643 * Returns the maximum allowed size of the free list.
647 isc_mempool_setfreemax(isc_mempool_t *mpctx, unsigned int limit);
649 * Sets the maximum allowed size of the free list.
653 isc_mempool_getfreecount(isc_mempool_t *mpctx);
655 * Returns current size of the free list.
659 isc_mempool_getmaxalloc(isc_mempool_t *mpctx);
661 * Returns the maximum allowed number of allocations.
665 isc_mempool_setmaxalloc(isc_mempool_t *mpctx, unsigned int limit);
667 * Sets the maximum allowed number of allocations.
669 * Additional requirements:
674 isc_mempool_getallocated(isc_mempool_t *mpctx);
676 * Returns the number of items allocated from this pool.
680 isc_mempool_getfillcount(isc_mempool_t *mpctx);
682 * Returns the number of items allocated as a block from the parent memory
683 * context when the free list is empty.
687 isc_mempool_setfillcount(isc_mempool_t *mpctx, unsigned int limit);
689 * Sets the fillcount.
691 * Additional requirements:
697 * Pseudo-private functions for use via macros. Do not call directly.
700 ISCMEMFUNC(get)(isc_mem_t *, size_t _ISC_MEM_FLARG);
702 ISCMEMFUNC(putanddetach)(isc_mem_t **, void *, size_t _ISC_MEM_FLARG);
704 ISCMEMFUNC(put)(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
706 ISCMEMFUNC(allocate)(isc_mem_t *, size_t _ISC_MEM_FLARG);
708 ISCMEMFUNC(reallocate)(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
710 ISCMEMFUNC(free)(isc_mem_t *, void * _ISC_MEM_FLARG);
712 ISCMEMFUNC(strdup)(isc_mem_t *, const char *_ISC_MEM_FLARG);
714 ISCMEMPOOLFUNC(get)(isc_mempool_t * _ISC_MEM_FLARG);
716 ISCMEMPOOLFUNC(put)(isc_mempool_t *, void * _ISC_MEM_FLARG);
718 #ifdef USE_MEMIMPREGISTER
721 * See isc_mem_create2() above.
724 (*isc_memcreatefunc_t)(size_t init_max_size, size_t target_size,
725 isc_mem_t **ctxp, unsigned int flags);
728 isc_mem_register(isc_memcreatefunc_t createfunc);
730 * Register a new memory management implementation and add it to the list of
731 * supported implementations. This function must be called when a different
732 * memory management library is used than the one contained in the ISC library.
736 isc__mem_register(void);
738 * A short cut function that specifies the memory management module in the ISC
739 * library for isc_mem_register(). An application that uses the ISC library
740 * usually do not have to care about this function: it would call
741 * isc_lib_register(), which internally calls this function.
743 #endif /* USE_MEMIMPREGISTER */
747 #endif /* ISC_MEM_H */