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+/*
+ * Copyright (C) 2004-2012 Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (C) 1997-2001 Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id$ */
+
+#ifndef ISC_MEM_H
+#define ISC_MEM_H 1
+
+/*! \file isc/mem.h */
+
+#include <stdio.h>
+
+#include <isc/lang.h>
+#include <isc/mutex.h>
+#include <isc/platform.h>
+#include <isc/types.h>
+#include <isc/xml.h>
+
+ISC_LANG_BEGINDECLS
+
+#define ISC_MEM_LOWATER 0
+#define ISC_MEM_HIWATER 1
+typedef void (*isc_mem_water_t)(void *, int);
+
+typedef void * (*isc_memalloc_t)(void *, size_t);
+typedef void (*isc_memfree_t)(void *, void *);
+
+/*%
+ * Define ISC_MEM_DEBUG=1 to make all functions that free memory
+ * set the pointer being freed to NULL after being freed.
+ * This is the default; set ISC_MEM_DEBUG=0 to disable it.
+ */
+#ifndef ISC_MEM_DEBUG
+#define ISC_MEM_DEBUG 1
+#endif
+
+/*%
+ * Define ISC_MEM_TRACKLINES=1 to turn on detailed tracing of memory
+ * allocation and freeing by file and line number.
+ */
+#ifndef ISC_MEM_TRACKLINES
+#define ISC_MEM_TRACKLINES 1
+#endif
+
+/*%
+ * Define ISC_MEM_CHECKOVERRUN=1 to turn on checks for using memory outside
+ * the requested space. This will increase the size of each allocation.
+ */
+#ifndef ISC_MEM_CHECKOVERRUN
+#define ISC_MEM_CHECKOVERRUN 1
+#endif
+
+/*%
+ * Define ISC_MEM_FILL=1 to fill each block of memory returned to the system
+ * with the byte string '0xbe'. This helps track down uninitialized pointers
+ * and the like. On freeing memory, the space is filled with '0xde' for
+ * the same reasons.
+ */
+#ifndef ISC_MEM_FILL
+#define ISC_MEM_FILL 1
+#endif
+
+/*%
+ * Define ISC_MEMPOOL_NAMES=1 to make memory pools store a symbolic
+ * name so that the leaking pool can be more readily identified in
+ * case of a memory leak.
+ */
+#ifndef ISC_MEMPOOL_NAMES
+#define ISC_MEMPOOL_NAMES 1
+#endif
+
+LIBISC_EXTERNAL_DATA extern unsigned int isc_mem_debugging;
+/*@{*/
+#define ISC_MEM_DEBUGTRACE 0x00000001U
+#define ISC_MEM_DEBUGRECORD 0x00000002U
+#define ISC_MEM_DEBUGUSAGE 0x00000004U
+#define ISC_MEM_DEBUGSIZE 0x00000008U
+#define ISC_MEM_DEBUGCTX 0x00000010U
+#define ISC_MEM_DEBUGALL 0x0000001FU
+/*!<
+ * The variable isc_mem_debugging holds a set of flags for
+ * turning certain memory debugging options on or off at
+ * runtime. It is initialized to the value ISC_MEM_DEGBUGGING,
+ * which is 0 by default but may be overridden at compile time.
+ * The following flags can be specified:
+ *
+ * \li #ISC_MEM_DEBUGTRACE
+ * Log each allocation and free to isc_lctx.
+ *
+ * \li #ISC_MEM_DEBUGRECORD
+ * Remember each allocation, and match them up on free.
+ * Crash if a free doesn't match an allocation.
+ *
+ * \li #ISC_MEM_DEBUGUSAGE
+ * If a hi_water mark is set, print the maximum inuse memory
+ * every time it is raised once it exceeds the hi_water mark.
+ *
+ * \li #ISC_MEM_DEBUGSIZE
+ * Check the size argument being passed to isc_mem_put() matches
+ * that passed to isc_mem_get().
+ *
+ * \li #ISC_MEM_DEBUGCTX
+ * Check the mctx argument being passed to isc_mem_put() matches
+ * that passed to isc_mem_get().
+ */
+/*@}*/
+
+#if ISC_MEM_TRACKLINES
+#define _ISC_MEM_FILELINE , __FILE__, __LINE__
+#define _ISC_MEM_FLARG , const char *, unsigned int
+#else
+#define _ISC_MEM_FILELINE
+#define _ISC_MEM_FLARG
+#endif
+
+/*!
+ * Define ISC_MEM_USE_INTERNAL_MALLOC=1 to use the internal malloc()
+ * implementation in preference to the system one. The internal malloc()
+ * is very space-efficient, and quite fast on uniprocessor systems. It
+ * performs poorly on multiprocessor machines.
+ * JT: we can overcome the performance issue on multiprocessor machines
+ * by carefully separating memory contexts.
+ */
+
+#ifndef ISC_MEM_USE_INTERNAL_MALLOC
+#define ISC_MEM_USE_INTERNAL_MALLOC 1
+#endif
+
+/*
+ * Flags for isc_mem_create2()calls.
+ */
+#define ISC_MEMFLAG_NOLOCK 0x00000001 /* no lock is necessary */
+#define ISC_MEMFLAG_INTERNAL 0x00000002 /* use internal malloc */
+#if ISC_MEM_USE_INTERNAL_MALLOC
+#define ISC_MEMFLAG_DEFAULT ISC_MEMFLAG_INTERNAL
+#else
+#define ISC_MEMFLAG_DEFAULT 0
+#endif
+
+
+/*%<
+ * We use either isc___mem (three underscores) or isc__mem (two) depending on
+ * whether it's for BIND9's internal purpose (with -DBIND9) or generic export
+ * library. This condition is generally handled in isc/namespace.h, but for
+ * Windows it doesn't work if it involves multiple times of macro expansion
+ * (such as isc_mem to isc__mem then to isc___mem). The following definitions
+ * are used to work around this portability issue. Right now, we don't support
+ * the export library for Windows, so we always use the three-underscore
+ * version.
+ */
+#ifdef WIN32
+#define ISCMEMFUNC(sfx) isc___mem_ ## sfx
+#define ISCMEMPOOLFUNC(sfx) isc___mempool_ ## sfx
+#else
+#define ISCMEMFUNC(sfx) isc__mem_ ## sfx
+#define ISCMEMPOOLFUNC(sfx) isc__mempool_ ## sfx
+#endif
+
+#define isc_mem_get(c, s) ISCMEMFUNC(get)((c), (s) _ISC_MEM_FILELINE)
+#define isc_mem_allocate(c, s) ISCMEMFUNC(allocate)((c), (s) _ISC_MEM_FILELINE)
+#define isc_mem_reallocate(c, p, s) ISCMEMFUNC(reallocate)((c), (p), (s) _ISC_MEM_FILELINE)
+#define isc_mem_strdup(c, p) ISCMEMFUNC(strdup)((c), (p) _ISC_MEM_FILELINE)
+#define isc_mempool_get(c) ISCMEMPOOLFUNC(get)((c) _ISC_MEM_FILELINE)
+
+/*%
+ * isc_mem_putanddetach() is a convenience function for use where you
+ * have a structure with an attached memory context.
+ *
+ * Given:
+ *
+ * \code
+ * struct {
+ * ...
+ * isc_mem_t *mctx;
+ * ...
+ * } *ptr;
+ *
+ * isc_mem_t *mctx;
+ *
+ * isc_mem_putanddetach(&ptr->mctx, ptr, sizeof(*ptr));
+ * \endcode
+ *
+ * is the equivalent of:
+ *
+ * \code
+ * mctx = NULL;
+ * isc_mem_attach(ptr->mctx, &mctx);
+ * isc_mem_detach(&ptr->mctx);
+ * isc_mem_put(mctx, ptr, sizeof(*ptr));
+ * isc_mem_detach(&mctx);
+ * \endcode
+ */
+
+/*% memory and memory pool methods */
+typedef struct isc_memmethods {
+ void (*attach)(isc_mem_t *source, isc_mem_t **targetp);
+ void (*detach)(isc_mem_t **mctxp);
+ void (*destroy)(isc_mem_t **mctxp);
+ void *(*memget)(isc_mem_t *mctx, size_t size _ISC_MEM_FLARG);
+ void (*memput)(isc_mem_t *mctx, void *ptr, size_t size _ISC_MEM_FLARG);
+ void (*memputanddetach)(isc_mem_t **mctxp, void *ptr,
+ size_t size _ISC_MEM_FLARG);
+ void *(*memallocate)(isc_mem_t *mctx, size_t size _ISC_MEM_FLARG);
+ void *(*memreallocate)(isc_mem_t *mctx, void *ptr,
+ size_t size _ISC_MEM_FLARG);
+ char *(*memstrdup)(isc_mem_t *mctx, const char *s _ISC_MEM_FLARG);
+ void (*memfree)(isc_mem_t *mctx, void *ptr _ISC_MEM_FLARG);
+ void (*setdestroycheck)(isc_mem_t *mctx, isc_boolean_t flag);
+ void (*setwater)(isc_mem_t *ctx, isc_mem_water_t water,
+ void *water_arg, size_t hiwater, size_t lowater);
+ void (*waterack)(isc_mem_t *ctx, int flag);
+ size_t (*inuse)(isc_mem_t *mctx);
+ isc_boolean_t (*isovermem)(isc_mem_t *mctx);
+ isc_result_t (*mpcreate)(isc_mem_t *mctx, size_t size,
+ isc_mempool_t **mpctxp);
+} isc_memmethods_t;
+
+typedef struct isc_mempoolmethods {
+ void (*destroy)(isc_mempool_t **mpctxp);
+ void *(*get)(isc_mempool_t *mpctx _ISC_MEM_FLARG);
+ void (*put)(isc_mempool_t *mpctx, void *mem _ISC_MEM_FLARG);
+ unsigned int (*getallocated)(isc_mempool_t *mpctx);
+ void (*setmaxalloc)(isc_mempool_t *mpctx, unsigned int limit);
+ void (*setfreemax)(isc_mempool_t *mpctx, unsigned int limit);
+ void (*setname)(isc_mempool_t *mpctx, const char *name);
+ void (*associatelock)(isc_mempool_t *mpctx, isc_mutex_t *lock);
+ void (*setfillcount)(isc_mempool_t *mpctx, unsigned int limit);
+} isc_mempoolmethods_t;
+
+/*%
+ * This structure is actually just the common prefix of a memory context
+ * implementation's version of an isc_mem_t.
+ * \brief
+ * Direct use of this structure by clients is forbidden. mctx implementations
+ * may change the structure. 'magic' must be ISCAPI_MCTX_MAGIC for any of the
+ * isc_mem_ routines to work. mctx implementations must maintain all mctx
+ * invariants.
+ */
+struct isc_mem {
+ unsigned int impmagic;
+ unsigned int magic;
+ isc_memmethods_t *methods;
+};
+
+#define ISCAPI_MCTX_MAGIC ISC_MAGIC('A','m','c','x')
+#define ISCAPI_MCTX_VALID(m) ((m) != NULL && \
+ (m)->magic == ISCAPI_MCTX_MAGIC)
+
+/*%
+ * This is the common prefix of a memory pool context. The same note as
+ * that for the mem structure applies.
+ */
+struct isc_mempool {
+ unsigned int impmagic;
+ unsigned int magic;
+ isc_mempoolmethods_t *methods;
+};
+
+#define ISCAPI_MPOOL_MAGIC ISC_MAGIC('A','m','p','l')
+#define ISCAPI_MPOOL_VALID(mp) ((mp) != NULL && \
+ (mp)->magic == ISCAPI_MPOOL_MAGIC)
+
+#if ISC_MEM_DEBUG
+#define isc_mem_put(c, p, s) \
+ do { \
+ ISCMEMFUNC(put)((c), (p), (s) _ISC_MEM_FILELINE); \
+ (p) = NULL; \
+ } while (0)
+#define isc_mem_putanddetach(c, p, s) \
+ do { \
+ ISCMEMFUNC(putanddetach)((c), (p), (s) _ISC_MEM_FILELINE); \
+ (p) = NULL; \
+ } while (0)
+#define isc_mem_free(c, p) \
+ do { \
+ ISCMEMFUNC(free)((c), (p) _ISC_MEM_FILELINE); \
+ (p) = NULL; \
+ } while (0)
+#define isc_mempool_put(c, p) \
+ do { \
+ ISCMEMPOOLFUNC(put)((c), (p) _ISC_MEM_FILELINE); \
+ (p) = NULL; \
+ } while (0)
+#else
+#define isc_mem_put(c, p, s) ISCMEMFUNC(put)((c), (p), (s) _ISC_MEM_FILELINE)
+#define isc_mem_putanddetach(c, p, s) \
+ ISCMEMFUNC(putanddetach)((c), (p), (s) _ISC_MEM_FILELINE)
+#define isc_mem_free(c, p) ISCMEMFUNC(free)((c), (p) _ISC_MEM_FILELINE)
+#define isc_mempool_put(c, p) ISCMEMPOOLFUNC(put)((c), (p) _ISC_MEM_FILELINE)
+#endif
+
+/*@{*/
+isc_result_t
+isc_mem_create(size_t max_size, size_t target_size,
+ isc_mem_t **mctxp);
+
+isc_result_t
+isc_mem_create2(size_t max_size, size_t target_size,
+ isc_mem_t **mctxp, unsigned int flags);
+
+isc_result_t
+isc_mem_createx(size_t max_size, size_t target_size,
+ isc_memalloc_t memalloc, isc_memfree_t memfree,
+ void *arg, isc_mem_t **mctxp);
+
+isc_result_t
+isc_mem_createx2(size_t max_size, size_t target_size,
+ isc_memalloc_t memalloc, isc_memfree_t memfree,
+ void *arg, isc_mem_t **mctxp, unsigned int flags);
+
+/*!<
+ * \brief Create a memory context.
+ *
+ * 'max_size' and 'target_size' are tuning parameters. When
+ * ISC_MEMFLAG_INTERNAL is set, allocations smaller than 'max_size'
+ * will be satisfied by getting blocks of size 'target_size' from the
+ * system allocator and breaking them up into pieces; larger allocations
+ * will use the system allocator directly. If 'max_size' and/or
+ * 'target_size' are zero, default values will be * used. When
+ * ISC_MEMFLAG_INTERNAL is not set, 'target_size' is ignored.
+ *
+ * 'max_size' is also used to size the statistics arrays and the array
+ * used to record active memory when ISC_MEM_DEBUGRECORD is set. Setting
+ * 'max_size' too low can have detrimental effects on performance.
+ *
+ * A memory context created using isc_mem_createx() will obtain
+ * memory from the system by calling 'memalloc' and 'memfree',
+ * passing them the argument 'arg'. A memory context created
+ * using isc_mem_create() will use the standard library malloc()
+ * and free().
+ *
+ * If ISC_MEMFLAG_NOLOCK is set in 'flags', the corresponding memory context
+ * will be accessed without locking. The user who creates the context must
+ * ensure there be no race. Since this can be a source of bug, it is generally
+ * inadvisable to use this flag unless the user is very sure about the race
+ * condition and the access to the object is highly performance sensitive.
+ *
+ * Requires:
+ * mctxp != NULL && *mctxp == NULL */
+/*@}*/
+
+/*@{*/
+void
+isc_mem_attach(isc_mem_t *, isc_mem_t **);
+void
+isc_mem_detach(isc_mem_t **);
+/*!<
+ * \brief Attach to / detach from a memory context.
+ *
+ * This is intended for applications that use multiple memory contexts
+ * in such a way that it is not obvious when the last allocations from
+ * a given context has been freed and destroying the context is safe.
+ *
+ * Most applications do not need to call these functions as they can
+ * simply create a single memory context at the beginning of main()
+ * and destroy it at the end of main(), thereby guaranteeing that it
+ * is not destroyed while there are outstanding allocations.
+ */
+/*@}*/
+
+void
+isc_mem_destroy(isc_mem_t **);
+/*%<
+ * Destroy a memory context.
+ */
+
+isc_result_t
+isc_mem_ondestroy(isc_mem_t *ctx,
+ isc_task_t *task,
+ isc_event_t **event);
+/*%<
+ * Request to be notified with an event when a memory context has
+ * been successfully destroyed.
+ */
+
+void
+isc_mem_stats(isc_mem_t *mctx, FILE *out);
+/*%<
+ * Print memory usage statistics for 'mctx' on the stream 'out'.
+ */
+
+void
+isc_mem_setdestroycheck(isc_mem_t *mctx,
+ isc_boolean_t on);
+/*%<
+ * If 'on' is ISC_TRUE, 'mctx' will check for memory leaks when
+ * destroyed and abort the program if any are present.
+ */
+
+/*@{*/
+void
+isc_mem_setquota(isc_mem_t *, size_t);
+size_t
+isc_mem_getquota(isc_mem_t *);
+/*%<
+ * Set/get the memory quota of 'mctx'. This is a hard limit
+ * on the amount of memory that may be allocated from mctx;
+ * if it is exceeded, allocations will fail.
+ */
+/*@}*/
+
+size_t
+isc_mem_inuse(isc_mem_t *mctx);
+/*%<
+ * Get an estimate of the number of memory in use in 'mctx', in bytes.
+ * This includes quantization overhead, but does not include memory
+ * allocated from the system but not yet used.
+ */
+
+isc_boolean_t
+isc_mem_isovermem(isc_mem_t *mctx);
+/*%<
+ * Return true iff the memory context is in "over memory" state, i.e.,
+ * a hiwater mark has been set and the used amount of memory has exceeds
+ * the mark.
+ */
+
+void
+isc_mem_setwater(isc_mem_t *mctx, isc_mem_water_t water, void *water_arg,
+ size_t hiwater, size_t lowater);
+/*%<
+ * Set high and low water marks for this memory context.
+ *
+ * When the memory usage of 'mctx' exceeds 'hiwater',
+ * '(water)(water_arg, #ISC_MEM_HIWATER)' will be called. 'water' needs to
+ * call isc_mem_waterack() with #ISC_MEM_HIWATER to acknowledge the state
+ * change. 'water' may be called multiple times.
+ *
+ * When the usage drops below 'lowater', 'water' will again be called, this
+ * time with #ISC_MEM_LOWATER. 'water' need to calls isc_mem_waterack() with
+ * #ISC_MEM_LOWATER to acknowledge the change.
+ *
+ * static void
+ * water(void *arg, int mark) {
+ * struct foo *foo = arg;
+ *
+ * LOCK(&foo->marklock);
+ * if (foo->mark != mark) {
+ * foo->mark = mark;
+ * ....
+ * isc_mem_waterack(foo->mctx, mark);
+ * }
+ * UNLOCK(&foo->marklock);
+ * }
+ *
+ * If 'water' is NULL then 'water_arg', 'hi_water' and 'lo_water' are
+ * ignored and the state is reset.
+ *
+ * Requires:
+ *
+ * 'water' is not NULL.
+ * hi_water >= lo_water
+ */
+
+void
+isc_mem_waterack(isc_mem_t *ctx, int mark);
+/*%<
+ * Called to acknowledge changes in signaled by calls to 'water'.
+ */
+
+void
+isc_mem_printactive(isc_mem_t *mctx, FILE *file);
+/*%<
+ * Print to 'file' all active memory in 'mctx'.
+ *
+ * Requires ISC_MEM_DEBUGRECORD to have been set.
+ */
+
+void
+isc_mem_printallactive(FILE *file);
+/*%<
+ * Print to 'file' all active memory in all contexts.
+ *
+ * Requires ISC_MEM_DEBUGRECORD to have been set.
+ */
+
+void
+isc_mem_checkdestroyed(FILE *file);
+/*%<
+ * Check that all memory contexts have been destroyed.
+ * Prints out those that have not been.
+ * Fatally fails if there are still active contexts.
+ */
+
+unsigned int
+isc_mem_references(isc_mem_t *ctx);
+/*%<
+ * Return the current reference count.
+ */
+
+void
+isc_mem_setname(isc_mem_t *ctx, const char *name, void *tag);
+/*%<
+ * Name 'ctx'.
+ *
+ * Notes:
+ *
+ *\li Only the first 15 characters of 'name' will be copied.
+ *
+ *\li 'tag' is for debugging purposes only.
+ *
+ * Requires:
+ *
+ *\li 'ctx' is a valid ctx.
+ */
+
+const char *
+isc_mem_getname(isc_mem_t *ctx);
+/*%<
+ * Get the name of 'ctx', as previously set using isc_mem_setname().
+ *
+ * Requires:
+ *\li 'ctx' is a valid ctx.
+ *
+ * Returns:
+ *\li A non-NULL pointer to a null-terminated string.
+ * If the ctx has not been named, the string is
+ * empty.
+ */
+
+void *
+isc_mem_gettag(isc_mem_t *ctx);
+/*%<
+ * Get the tag value for 'task', as previously set using isc_mem_setname().
+ *
+ * Requires:
+ *\li 'ctx' is a valid ctx.
+ *
+ * Notes:
+ *\li This function is for debugging purposes only.
+ *
+ * Requires:
+ *\li 'ctx' is a valid task.
+ */
+
+#ifdef HAVE_LIBXML2
+void
+isc_mem_renderxml(xmlTextWriterPtr writer);
+/*%<
+ * Render all contexts' statistics and status in XML for writer.
+ */
+#endif /* HAVE_LIBXML2 */
+
+/*
+ * Memory pools
+ */
+
+isc_result_t
+isc_mempool_create(isc_mem_t *mctx, size_t size, isc_mempool_t **mpctxp);
+/*%<
+ * Create a memory pool.
+ *
+ * Requires:
+ *\li mctx is a valid memory context.
+ *\li size > 0
+ *\li mpctxp != NULL and *mpctxp == NULL
+ *
+ * Defaults:
+ *\li maxalloc = UINT_MAX
+ *\li freemax = 1
+ *\li fillcount = 1
+ *
+ * Returns:
+ *\li #ISC_R_NOMEMORY -- not enough memory to create pool
+ *\li #ISC_R_SUCCESS -- all is well.
+ */
+
+void
+isc_mempool_destroy(isc_mempool_t **mpctxp);
+/*%<
+ * Destroy a memory pool.
+ *
+ * Requires:
+ *\li mpctxp != NULL && *mpctxp is a valid pool.
+ *\li The pool has no un"put" allocations outstanding
+ */
+
+void
+isc_mempool_setname(isc_mempool_t *mpctx, const char *name);
+/*%<
+ * Associate a name with a memory pool. At most 15 characters may be used.
+ *
+ * Requires:
+ *\li mpctx is a valid pool.
+ *\li name != NULL;
+ */
+
+void
+isc_mempool_associatelock(isc_mempool_t *mpctx, isc_mutex_t *lock);
+/*%<
+ * Associate a lock with this memory pool.
+ *
+ * This lock is used when getting or putting items using this memory pool,
+ * and it is also used to set or get internal state via the isc_mempool_get*()
+ * and isc_mempool_set*() set of functions.
+ *
+ * Multiple pools can each share a single lock. For instance, if "manager"
+ * type object contained pools for various sizes of events, and each of
+ * these pools used a common lock. Note that this lock must NEVER be used
+ * by other than mempool routines once it is given to a pool, since that can
+ * easily cause double locking.
+ *
+ * Requires:
+ *
+ *\li mpctpx is a valid pool.
+ *
+ *\li lock != NULL.
+ *
+ *\li No previous lock is assigned to this pool.
+ *
+ *\li The lock is initialized before calling this function via the normal
+ * means of doing that.
+ */
+
+/*
+ * The following functions get/set various parameters. Note that due to
+ * the unlocked nature of pools these are potentially random values unless
+ * the imposed externally provided locking protocols are followed.
+ *
+ * Also note that the quota limits will not always take immediate effect.
+ * For instance, setting "maxalloc" to a number smaller than the currently
+ * allocated count is permitted. New allocations will be refused until
+ * the count drops below this threshold.
+ *
+ * All functions require (in addition to other requirements):
+ * mpctx is a valid memory pool
+ */
+
+unsigned int
+isc_mempool_getfreemax(isc_mempool_t *mpctx);
+/*%<
+ * Returns the maximum allowed size of the free list.
+ */
+
+void
+isc_mempool_setfreemax(isc_mempool_t *mpctx, unsigned int limit);
+/*%<
+ * Sets the maximum allowed size of the free list.
+ */
+
+unsigned int
+isc_mempool_getfreecount(isc_mempool_t *mpctx);
+/*%<
+ * Returns current size of the free list.
+ */
+
+unsigned int
+isc_mempool_getmaxalloc(isc_mempool_t *mpctx);
+/*!<
+ * Returns the maximum allowed number of allocations.
+ */
+
+void
+isc_mempool_setmaxalloc(isc_mempool_t *mpctx, unsigned int limit);
+/*%<
+ * Sets the maximum allowed number of allocations.
+ *
+ * Additional requirements:
+ *\li limit > 0
+ */
+
+unsigned int
+isc_mempool_getallocated(isc_mempool_t *mpctx);
+/*%<
+ * Returns the number of items allocated from this pool.
+ */
+
+unsigned int
+isc_mempool_getfillcount(isc_mempool_t *mpctx);
+/*%<
+ * Returns the number of items allocated as a block from the parent memory
+ * context when the free list is empty.
+ */
+
+void
+isc_mempool_setfillcount(isc_mempool_t *mpctx, unsigned int limit);
+/*%<
+ * Sets the fillcount.
+ *
+ * Additional requirements:
+ *\li limit > 0
+ */
+
+
+/*
+ * Pseudo-private functions for use via macros. Do not call directly.
+ */
+void *
+ISCMEMFUNC(get)(isc_mem_t *, size_t _ISC_MEM_FLARG);
+void
+ISCMEMFUNC(putanddetach)(isc_mem_t **, void *, size_t _ISC_MEM_FLARG);
+void
+ISCMEMFUNC(put)(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
+void *
+ISCMEMFUNC(allocate)(isc_mem_t *, size_t _ISC_MEM_FLARG);
+void *
+ISCMEMFUNC(reallocate)(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
+void
+ISCMEMFUNC(free)(isc_mem_t *, void * _ISC_MEM_FLARG);
+char *
+ISCMEMFUNC(strdup)(isc_mem_t *, const char *_ISC_MEM_FLARG);
+void *
+ISCMEMPOOLFUNC(get)(isc_mempool_t * _ISC_MEM_FLARG);
+void
+ISCMEMPOOLFUNC(put)(isc_mempool_t *, void * _ISC_MEM_FLARG);
+
+#ifdef USE_MEMIMPREGISTER
+
+/*%<
+ * See isc_mem_create2() above.
+ */
+typedef isc_result_t
+(*isc_memcreatefunc_t)(size_t init_max_size, size_t target_size,
+ isc_mem_t **ctxp, unsigned int flags);
+
+isc_result_t
+isc_mem_register(isc_memcreatefunc_t createfunc);
+/*%<
+ * Register a new memory management implementation and add it to the list of
+ * supported implementations. This function must be called when a different
+ * memory management library is used than the one contained in the ISC library.
+ */
+
+isc_result_t
+isc__mem_register(void);
+/*%<
+ * A short cut function that specifies the memory management module in the ISC
+ * library for isc_mem_register(). An application that uses the ISC library
+ * usually do not have to care about this function: it would call
+ * isc_lib_register(), which internally calls this function.
+ */
+#endif /* USE_MEMIMPREGISTER */
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISC_MEM_H */