/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#include <config.h>

#include <inttypes.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <limits.h>

#include <isc/bind9.h>
#include <isc/json.h>
#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/msgs.h>
#include <isc/once.h>
#include <isc/ondestroy.h>
#include <isc/string.h>
#include <isc/strerror.h>
#include <isc/mutex.h>
#include <isc/print.h>
#include <isc/util.h>
#include <isc/xml.h>

#define MCTXLOCK(m, l) if (((m)->flags & ISC_MEMFLAG_NOLOCK) == 0) LOCK(l)
#define MCTXUNLOCK(m, l) if (((m)->flags & ISC_MEMFLAG_NOLOCK) == 0) UNLOCK(l)

#ifndef ISC_MEM_DEBUGGING
#define ISC_MEM_DEBUGGING 0
#endif
LIBISC_EXTERNAL_DATA unsigned int isc_mem_debugging = ISC_MEM_DEBUGGING;
LIBISC_EXTERNAL_DATA unsigned int isc_mem_defaultflags = ISC_MEMFLAG_DEFAULT;

/*
 * Constants.
 */

#define DEF_MAX_SIZE		1100
#define DEF_MEM_TARGET		4096
#define ALIGNMENT_SIZE		8U		/*%< must be a power of 2 */
#define NUM_BASIC_BLOCKS	64		/*%< must be > 1 */
#define TABLE_INCREMENT		1024
#define DEBUGLIST_COUNT		1024

/*
 * Types.
 */
typedef struct isc__mem isc__mem_t;
typedef struct isc__mempool isc__mempool_t;

#if ISC_MEM_TRACKLINES
typedef struct debuglink debuglink_t;
struct debuglink {
	ISC_LINK(debuglink_t)	link;
	const void	       *ptr[DEBUGLIST_COUNT];
	size_t			size[DEBUGLIST_COUNT];
	const char	       *file[DEBUGLIST_COUNT];
	unsigned int		line[DEBUGLIST_COUNT];
	unsigned int		count;
};

#define FLARG_PASS	, file, line
#define FLARG		, const char *file, unsigned int line
#else
#define FLARG_PASS
#define FLARG
#endif

typedef struct element element;
struct element {
	element *		next;
};

typedef struct {
	/*!
	 * This structure must be ALIGNMENT_SIZE bytes.
	 */
	union {
		size_t		size;
		isc__mem_t	*ctx;
		char		bytes[ALIGNMENT_SIZE];
	} u;
} size_info;

struct stats {
	unsigned long		gets;
	unsigned long		totalgets;
	unsigned long		blocks;
	unsigned long		freefrags;
};

#define MEM_MAGIC		ISC_MAGIC('M', 'e', 'm', 'C')
#define VALID_CONTEXT(c)	ISC_MAGIC_VALID(c, MEM_MAGIC)

#if ISC_MEM_TRACKLINES
typedef ISC_LIST(debuglink_t)	debuglist_t;
#endif

/* List of all active memory contexts. */

static ISC_LIST(isc__mem_t)	contexts;

static isc_once_t		once = ISC_ONCE_INIT;
static isc_mutex_t		contextslock;
static isc_mutex_t 		createlock;

/*%
 * Total size of lost memory due to a bug of external library.
 * Locked by the global lock.
 */
static uint64_t		totallost;

struct isc__mem {
	isc_mem_t		common;
	isc_ondestroy_t		ondestroy;
	unsigned int		flags;
	isc_mutex_t		lock;
	isc_memalloc_t		memalloc;
	isc_memfree_t		memfree;
	void *			arg;
	size_t			max_size;
	bool		checkfree;
	struct stats *		stats;
	unsigned int		references;
	char			name[16];
	void *			tag;
	size_t			quota;
	size_t			total;
	size_t			inuse;
	size_t			maxinuse;
	size_t			hi_water;
	size_t			lo_water;
	bool		hi_called;
	bool		is_overmem;
	isc_mem_water_t		water;
	void *			water_arg;
	ISC_LIST(isc__mempool_t) pools;
	unsigned int		poolcnt;

	/*  ISC_MEMFLAG_INTERNAL */
	size_t			mem_target;
	element **		freelists;
	element *		basic_blocks;
	unsigned char **	basic_table;
	unsigned int		basic_table_count;
	unsigned int		basic_table_size;
	unsigned char *		lowest;
	unsigned char *		highest;

#if ISC_MEM_TRACKLINES
	debuglist_t *	 	debuglist;
	unsigned int		debuglistcnt;
#endif

	unsigned int		memalloc_failures;
	ISC_LINK(isc__mem_t)	link;
};

#define MEMPOOL_MAGIC		ISC_MAGIC('M', 'E', 'M', 'p')
#define VALID_MEMPOOL(c)	ISC_MAGIC_VALID(c, MEMPOOL_MAGIC)

struct isc__mempool {
	/* always unlocked */
	isc_mempool_t	common;		/*%< common header of mempool's */
	isc_mutex_t    *lock;		/*%< optional lock */
	isc__mem_t      *mctx;		/*%< our memory context */
	/*%< locked via the memory context's lock */
	ISC_LINK(isc__mempool_t)	link;	/*%< next pool in this mem context */
	/*%< optionally locked from here down */
	element	       *items;		/*%< low water item list */
	size_t		size;		/*%< size of each item on this pool */
	unsigned int	maxalloc;	/*%< max number of items allowed */
	unsigned int	allocated;	/*%< # of items currently given out */
	unsigned int	freecount;	/*%< # of items on reserved list */
	unsigned int	freemax;	/*%< # of items allowed on free list */
	unsigned int	fillcount;	/*%< # of items to fetch on each fill */
	/*%< Stats only. */
	unsigned int	gets;		/*%< # of requests to this pool */
	/*%< Debugging only. */
#if ISC_MEMPOOL_NAMES
	char		name[16];	/*%< printed name in stats reports */
#endif
};

/*
 * Private Inline-able.
 */

#if ! ISC_MEM_TRACKLINES
#define ADD_TRACE(a, b, c, d, e)
#define DELETE_TRACE(a, b, c, d, e)
#define ISC_MEMFUNC_SCOPE
#else
#define TRACE_OR_RECORD (ISC_MEM_DEBUGTRACE|ISC_MEM_DEBUGRECORD)
#define ADD_TRACE(a, b, c, d, e) \
	do { \
		if ((isc_mem_debugging & TRACE_OR_RECORD) != 0 && \
		     b != NULL) \
			 add_trace_entry(a, b, c, d, e); \
	} while (0)
#define DELETE_TRACE(a, b, c, d, e)					\
	do {								\
		if ((isc_mem_debugging & TRACE_OR_RECORD) != 0 &&	\
		    b != NULL)						\
			delete_trace_entry(a, b, c, d, e);		\
	} while(0)

static void
print_active(isc__mem_t *ctx, FILE *out);

#endif /* ISC_MEM_TRACKLINES */

/*%
 * The following are intended for internal use (indicated by "isc__"
 * prefix) but are not declared as static, allowing direct access
 * from unit tests, etc.
 */

isc_result_t
isc__mem_create2(size_t init_max_size, size_t target_size,
		 isc_mem_t **ctxp, unsigned int flags);
void
isc__mem_attach(isc_mem_t *source, isc_mem_t **targetp);
void
isc__mem_detach(isc_mem_t **ctxp);
void
isc___mem_putanddetach(isc_mem_t **ctxp, void *ptr, size_t size FLARG);
void
isc__mem_destroy(isc_mem_t **ctxp);
isc_result_t
isc__mem_ondestroy(isc_mem_t *ctx, isc_task_t *task, isc_event_t **event);
void *
isc___mem_get(isc_mem_t *ctx, size_t size FLARG);
void
isc___mem_put(isc_mem_t *ctx, void *ptr, size_t size FLARG);
void
isc__mem_stats(isc_mem_t *ctx, FILE *out);
void *
isc___mem_allocate(isc_mem_t *ctx, size_t size FLARG);
void *
isc___mem_reallocate(isc_mem_t *ctx, void *ptr, size_t size FLARG);
void
isc___mem_free(isc_mem_t *ctx, void *ptr FLARG);
char *
isc___mem_strdup(isc_mem_t *mctx, const char *s FLARG);
void
isc__mem_setdestroycheck(isc_mem_t *ctx, bool flag);
void
isc__mem_setquota(isc_mem_t *ctx, size_t quota);
size_t
isc__mem_getquota(isc_mem_t *ctx);
size_t
isc__mem_inuse(isc_mem_t *ctx);
size_t
isc__mem_maxinuse(isc_mem_t *ctx);
size_t
isc__mem_total(isc_mem_t *ctx);
bool
isc__mem_isovermem(isc_mem_t *ctx);
void
isc__mem_setwater(isc_mem_t *ctx, isc_mem_water_t water, void *water_arg,
		  size_t hiwater, size_t lowater);
void
isc__mem_waterack(isc_mem_t *ctx0, int flag);
void
isc__mem_setname(isc_mem_t *ctx, const char *name, void *tag);
const char *
isc__mem_getname(isc_mem_t *ctx);
void *
isc__mem_gettag(isc_mem_t *ctx);
isc_result_t
isc__mempool_create(isc_mem_t *mctx, size_t size, isc_mempool_t **mpctxp);
void
isc__mempool_setname(isc_mempool_t *mpctx, const char *name);
void
isc__mempool_destroy(isc_mempool_t **mpctxp);
void
isc__mempool_associatelock(isc_mempool_t *mpctx, isc_mutex_t *lock);
void *
isc___mempool_get(isc_mempool_t *mpctx FLARG);
void
isc___mempool_put(isc_mempool_t *mpctx, void *mem FLARG);
void
isc__mempool_setfreemax(isc_mempool_t *mpctx, unsigned int limit);
unsigned int
isc__mempool_getfreemax(isc_mempool_t *mpctx);
unsigned int
isc__mempool_getfreecount(isc_mempool_t *mpctx);
void
isc__mempool_setmaxalloc(isc_mempool_t *mpctx, unsigned int limit);
unsigned int
isc__mempool_getmaxalloc(isc_mempool_t *mpctx);
unsigned int
isc__mempool_getallocated(isc_mempool_t *mpctx);
void
isc__mempool_setfillcount(isc_mempool_t *mpctx, unsigned int limit);
unsigned int
isc__mempool_getfillcount(isc_mempool_t *mpctx);
void
isc__mem_printactive(isc_mem_t *ctx0, FILE *file);
void
isc__mem_printallactive(FILE *file);
unsigned int
isc__mem_references(isc_mem_t *ctx0);

static struct isc__memmethods {
	isc_memmethods_t methods;

	/*%
	 * The following are defined just for avoiding unused static functions.
	 */
	void *createx, *create, *create2, *ondestroy, *stats,
	     *setquota, *getquota, *setname, *getname, *gettag;
} memmethods = {
	{
		isc__mem_attach,
		isc__mem_detach,
		isc__mem_destroy,
		isc___mem_get,
		isc___mem_put,
		isc___mem_putanddetach,
		isc___mem_allocate,
		isc___mem_reallocate,
		isc___mem_strdup,
		isc___mem_free,
		isc__mem_setdestroycheck,
		isc__mem_setwater,
		isc__mem_waterack,
		isc__mem_inuse,
		isc__mem_maxinuse,
		isc__mem_total,
		isc__mem_isovermem,
		isc__mempool_create
	},
	(void *)isc_mem_createx,
	(void *)isc_mem_create,
	(void *)isc_mem_create2,
	(void *)isc_mem_ondestroy,
	(void *)isc_mem_stats,
	(void *)isc_mem_setquota,
	(void *)isc_mem_getquota,
	(void *)isc_mem_setname,
	(void *)isc_mem_getname,
	(void *)isc_mem_gettag
};

static struct isc__mempoolmethods {
	isc_mempoolmethods_t methods;

	/*%
	 * The following are defined just for avoiding unused static functions.
	 */
	void *getfreemax, *getfreecount, *getmaxalloc, *getfillcount;
} mempoolmethods = {
	{
		isc__mempool_destroy,
		isc___mempool_get,
		isc___mempool_put,
		isc__mempool_getallocated,
		isc__mempool_setmaxalloc,
		isc__mempool_setfreemax,
		isc__mempool_setname,
		isc__mempool_associatelock,
		isc__mempool_setfillcount
	},
	(void *)isc_mempool_getfreemax,
	(void *)isc_mempool_getfreecount,
	(void *)isc_mempool_getmaxalloc,
	(void *)isc_mempool_getfillcount
};

#if ISC_MEM_TRACKLINES
/*!
 * mctx must be locked.
 */
static inline void
add_trace_entry(isc__mem_t *mctx, const void *ptr, size_t size FLARG) {
	debuglink_t *dl;
	unsigned int i;
	size_t mysize = size;

	if ((isc_mem_debugging & ISC_MEM_DEBUGTRACE) != 0)
		fprintf(stderr, isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
					       ISC_MSG_ADDTRACE,
					       "add %p size %u "
					       "file %s line %u mctx %p\n"),
			ptr, size, file, line, mctx);

	if (mctx->debuglist == NULL)
		return;

	if (mysize > mctx->max_size)
		mysize = mctx->max_size;

	dl = ISC_LIST_HEAD(mctx->debuglist[mysize]);
	while (dl != NULL) {
		if (dl->count == DEBUGLIST_COUNT)
			goto next;
		for (i = 0; i < DEBUGLIST_COUNT; i++) {
			if (dl->ptr[i] == NULL) {
				dl->ptr[i] = ptr;
				dl->size[i] = size;
				dl->file[i] = file;
				dl->line[i] = line;
				dl->count++;
				return;
			}
		}
	next:
		dl = ISC_LIST_NEXT(dl, link);
	}

	dl = malloc(sizeof(debuglink_t));
	INSIST(dl != NULL);

	ISC_LINK_INIT(dl, link);
	for (i = 1; i < DEBUGLIST_COUNT; i++) {
		dl->ptr[i] = NULL;
		dl->size[i] = 0;
		dl->file[i] = NULL;
		dl->line[i] = 0;
	}

	dl->ptr[0] = ptr;
	dl->size[0] = size;
	dl->file[0] = file;
	dl->line[0] = line;
	dl->count = 1;

	ISC_LIST_PREPEND(mctx->debuglist[mysize], dl, link);
	mctx->debuglistcnt++;
}

static inline void
delete_trace_entry(isc__mem_t *mctx, const void *ptr, size_t size,
		   const char *file, unsigned int line)
{
	debuglink_t *dl;
	unsigned int i;

	if ((isc_mem_debugging & ISC_MEM_DEBUGTRACE) != 0)
		fprintf(stderr, isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
					       ISC_MSG_DELTRACE,
					       "del %p size %u "
					       "file %s line %u mctx %p\n"),
			ptr, size, file, line, mctx);

	if (mctx->debuglist == NULL)
		return;

	if (size > mctx->max_size)
		size = mctx->max_size;

	dl = ISC_LIST_HEAD(mctx->debuglist[size]);
	while (dl != NULL) {
		for (i = 0; i < DEBUGLIST_COUNT; i++) {
			if (dl->ptr[i] == ptr) {
				dl->ptr[i] = NULL;
				dl->size[i] = 0;
				dl->file[i] = NULL;
				dl->line[i] = 0;

				INSIST(dl->count > 0);
				dl->count--;
				if (dl->count == 0) {
					ISC_LIST_UNLINK(mctx->debuglist[size],
							dl, link);
					free(dl);
				}
				return;
			}
		}
		dl = ISC_LIST_NEXT(dl, link);
	}

	/*
	 * If we get here, we didn't find the item on the list.  We're
	 * screwed.
	 */
	INSIST(dl != NULL);
	ISC_UNREACHABLE();
}
#endif /* ISC_MEM_TRACKLINES */

static inline size_t
rmsize(size_t size) {
	/*
	 * round down to ALIGNMENT_SIZE
	 */
	return (size & (~(ALIGNMENT_SIZE - 1)));
}

static inline size_t
quantize(size_t size) {
	/*!
	 * Round up the result in order to get a size big
	 * enough to satisfy the request and be aligned on ALIGNMENT_SIZE
	 * byte boundaries.
	 */

	if (size == 0U)
		return (ALIGNMENT_SIZE);
	return ((size + ALIGNMENT_SIZE - 1) & (~(ALIGNMENT_SIZE - 1)));
}

static inline bool
more_basic_blocks(isc__mem_t *ctx) {
	void *tmp;
	unsigned char *curr, *next;
	unsigned char *first, *last;
	unsigned char **table;
	unsigned int table_size;
	size_t increment;
	int i;

	/* Require: we hold the context lock. */

	/*
	 * Did we hit the quota for this context?
	 */
	increment = NUM_BASIC_BLOCKS * ctx->mem_target;
	if (ctx->quota != 0U && ctx->total + increment > ctx->quota)
		return (false);

	INSIST(ctx->basic_table_count <= ctx->basic_table_size);
	if (ctx->basic_table_count == ctx->basic_table_size) {
		table_size = ctx->basic_table_size + TABLE_INCREMENT;
		table = (ctx->memalloc)(ctx->arg,
					table_size * sizeof(unsigned char *));
		if (table == NULL) {
			ctx->memalloc_failures++;
			return (false);
		}
		if (ctx->basic_table_size != 0) {
			memmove(table, ctx->basic_table,
				ctx->basic_table_size *
				  sizeof(unsigned char *));
			(ctx->memfree)(ctx->arg, ctx->basic_table);
		}
		ctx->basic_table = table;
		ctx->basic_table_size = table_size;
	}

	tmp = (ctx->memalloc)(ctx->arg, NUM_BASIC_BLOCKS * ctx->mem_target);
	if (tmp == NULL) {
		ctx->memalloc_failures++;
		return (false);
	}
	ctx->total += increment;
	ctx->basic_table[ctx->basic_table_count] = tmp;
	ctx->basic_table_count++;

	curr = tmp;
	next = curr + ctx->mem_target;
	for (i = 0; i < (NUM_BASIC_BLOCKS - 1); i++) {
		((element *)curr)->next = (element *)next;
		curr = next;
		next += ctx->mem_target;
	}
	/*
	 * curr is now pointing at the last block in the
	 * array.
	 */
	((element *)curr)->next = NULL;
	first = tmp;
	last = first + NUM_BASIC_BLOCKS * ctx->mem_target - 1;
	if (first < ctx->lowest || ctx->lowest == NULL)
		ctx->lowest = first;
	if (last > ctx->highest)
		ctx->highest = last;
	ctx->basic_blocks = tmp;

	return (true);
}

static inline bool
more_frags(isc__mem_t *ctx, size_t new_size) {
	int i, frags;
	size_t total_size;
	void *tmp;
	unsigned char *curr, *next;

	/*!
	 * Try to get more fragments by chopping up a basic block.
	 */

	if (ctx->basic_blocks == NULL) {
		if (!more_basic_blocks(ctx)) {
			/*
			 * We can't get more memory from the OS, or we've
			 * hit the quota for this context.
			 */
			/*
			 * XXXRTH  "At quota" notification here.
			 */
			return (false);
		}
	}

	total_size = ctx->mem_target;
	tmp = ctx->basic_blocks;
	ctx->basic_blocks = ctx->basic_blocks->next;
	frags = (int)(total_size / new_size);
	ctx->stats[new_size].blocks++;
	ctx->stats[new_size].freefrags += frags;
	/*
	 * Set up a linked-list of blocks of size
	 * "new_size".
	 */
	curr = tmp;
	next = curr + new_size;
	total_size -= new_size;
	for (i = 0; i < (frags - 1); i++) {
		((element *)curr)->next = (element *)next;
		curr = next;
		next += new_size;
		total_size -= new_size;
	}
	/*
	 * Add the remaining fragment of the basic block to a free list.
	 */
	total_size = rmsize(total_size);
	if (total_size > 0U) {
		((element *)next)->next = ctx->freelists[total_size];
		ctx->freelists[total_size] = (element *)next;
		ctx->stats[total_size].freefrags++;
	}
	/*
	 * curr is now pointing at the last block in the
	 * array.
	 */
	((element *)curr)->next = NULL;
	ctx->freelists[new_size] = tmp;

	return (true);
}

static inline void *
mem_getunlocked(isc__mem_t *ctx, size_t size) {
	size_t new_size = quantize(size);
	void *ret;

	if (new_size >= ctx->max_size) {
		/*
		 * memget() was called on something beyond our upper limit.
		 */
		if (ctx->quota != 0U && ctx->total + size > ctx->quota) {
			ret = NULL;
			goto done;
		}
		ret = (ctx->memalloc)(ctx->arg, size);
		if (ret == NULL) {
			ctx->memalloc_failures++;
			goto done;
		}
		ctx->total += size;
		ctx->inuse += size;
		ctx->stats[ctx->max_size].gets++;
		ctx->stats[ctx->max_size].totalgets++;
		/*
		 * If we don't set new_size to size, then the
		 * ISC_MEM_FILL code might write over bytes we
		 * don't own.
		 */
		new_size = size;
		goto done;
	}
	/*
	 * If there are no blocks in the free list for this size, get a chunk
	 * of memory and then break it up into "new_size"-sized blocks, adding
	 * them to the free list.
	 */
	if (ctx->freelists[new_size] == NULL && !more_frags(ctx, new_size))
		return (NULL);

	/*
	 * The free list uses the "rounded-up" size "new_size".
	 */

	ret = ctx->freelists[new_size];
	ctx->freelists[new_size] = ctx->freelists[new_size]->next;


	/*
	 * The stats[] uses the _actual_ "size" requested by the
	 * caller, with the caveat (in the code above) that "size" >= the
	 * max. size (max_size) ends up getting recorded as a call to
	 * max_size.
	 */
	ctx->stats[size].gets++;
	ctx->stats[size].totalgets++;
	ctx->stats[new_size].freefrags--;
	ctx->inuse += new_size;

 done:

#if ISC_MEM_FILL
	if (ret != NULL)
		memset(ret, 0xbe, new_size); /* Mnemonic for "beef". */
#endif

	return (ret);
}

#if ISC_MEM_FILL && ISC_MEM_CHECKOVERRUN
static inline void
check_overrun(void *mem, size_t size, size_t new_size) {
	unsigned char *cp;

	cp = (unsigned char *)mem;
	cp += size;
	while (size < new_size) {
		INSIST(*cp == 0xbe);
		cp++;
		size++;
	}
}
#endif

/* coverity[+free : arg-1] */
static inline void
mem_putunlocked(isc__mem_t *ctx, void *mem, size_t size) {
	size_t new_size = quantize(size);

	if (new_size >= ctx->max_size) {
		/*
		 * memput() called on something beyond our upper limit.
		 */
#if ISC_MEM_FILL
		memset(mem, 0xde, size); /* Mnemonic for "dead". */
#endif
		(ctx->memfree)(ctx->arg, mem);
		INSIST(ctx->stats[ctx->max_size].gets != 0U);
		ctx->stats[ctx->max_size].gets--;
		INSIST(size <= ctx->inuse);
		ctx->inuse -= size;
		return;
	}

#if ISC_MEM_FILL
#if ISC_MEM_CHECKOVERRUN
	check_overrun(mem, size, new_size);
#endif
	memset(mem, 0xde, new_size); /* Mnemonic for "dead". */
#endif

	/*
	 * The free list uses the "rounded-up" size "new_size".
	 */
	((element *)mem)->next = ctx->freelists[new_size];
	ctx->freelists[new_size] = (element *)mem;

	/*
	 * The stats[] uses the _actual_ "size" requested by the
	 * caller, with the caveat (in the code above) that "size" >= the
	 * max. size (max_size) ends up getting recorded as a call to
	 * max_size.
	 */
	INSIST(ctx->stats[size].gets != 0U);
	ctx->stats[size].gets--;
	ctx->stats[new_size].freefrags++;
	ctx->inuse -= new_size;
}

/*!
 * Perform a malloc, doing memory filling and overrun detection as necessary.
 */
static inline void *
mem_get(isc__mem_t *ctx, size_t size) {
	char *ret;

#if ISC_MEM_CHECKOVERRUN
	size += 1;
#endif

	ret = (ctx->memalloc)(ctx->arg, size);
	if (ret == NULL)
		ctx->memalloc_failures++;

#if ISC_MEM_FILL
	if (ret != NULL)
		memset(ret, 0xbe, size); /* Mnemonic for "beef". */
#else
#  if ISC_MEM_CHECKOVERRUN
	if (ret != NULL)
		ret[size-1] = 0xbe;
#  endif
#endif

	return (ret);
}

/*!
 * Perform a free, doing memory filling and overrun detection as necessary.
 */
/* coverity[+free : arg-1] */
static inline void
mem_put(isc__mem_t *ctx, void *mem, size_t size) {
#if ISC_MEM_CHECKOVERRUN
	INSIST(((unsigned char *)mem)[size] == 0xbe);
#endif
#if ISC_MEM_FILL
	memset(mem, 0xde, size); /* Mnemonic for "dead". */
#else
	UNUSED(size);
#endif
	(ctx->memfree)(ctx->arg, mem);
}

/*!
 * Update internal counters after a memory get.
 */
static inline void
mem_getstats(isc__mem_t *ctx, size_t size) {
	ctx->total += size;
	ctx->inuse += size;

	if (size > ctx->max_size) {
		ctx->stats[ctx->max_size].gets++;
		ctx->stats[ctx->max_size].totalgets++;
	} else {
		ctx->stats[size].gets++;
		ctx->stats[size].totalgets++;
	}
}

/*!
 * Update internal counters after a memory put.
 */
static inline void
mem_putstats(isc__mem_t *ctx, void *ptr, size_t size) {
	UNUSED(ptr);

	INSIST(ctx->inuse >= size);
	ctx->inuse -= size;

	if (size > ctx->max_size) {
		INSIST(ctx->stats[ctx->max_size].gets > 0U);
		ctx->stats[ctx->max_size].gets--;
	} else {
		INSIST(ctx->stats[size].gets > 0U);
		ctx->stats[size].gets--;
	}
}

/*
 * Private.
 */

static void *
default_memalloc(void *arg, size_t size) {
	UNUSED(arg);

	if (size == 0U) {
		size = 1;
	}

	return (malloc(size));
}

static void *
internal_memalloc(void *arg, size_t size) {
	void *ptr;
	UNUSED(arg);

	if (size == 0U) {
		size = 1;
	}

	ptr = malloc(size);

	/*
	 * If the space cannot be allocated, a null pointer is returned. If the
	 * size of the space requested is zero, the behavior is
	 * implementation-defined: either a null pointer is returned, or the
	 * behavior is as if the size were some nonzero value, except that the
	 * returned pointer shall not be used to access an object.
	 * [ISO9899 § 7.22.3]
	 *
	 * [ISO9899]
	 *   ISO/IEC WG 9899:2011: Programming languages - C.
	 *   International Organization for Standardization, Geneva, Switzerland.
	 *   http://www.open-std.org/JTC1/SC22/WG14/www/docs/n1570.pdf
	 */

	if (ptr == NULL && size != 0) {
		char strbuf[ISC_STRERRORSIZE];
		isc__strerror(errno, strbuf, sizeof(strbuf));
		isc_error_fatal(__FILE__, __LINE__, "malloc failed: %s", strbuf);
	}

	return (ptr);
}

static void
default_memfree(void *arg, void *ptr) {
	UNUSED(arg);
	free(ptr);
}

static void
initialize_action(void) {
	RUNTIME_CHECK(isc_mutex_init(&createlock) == ISC_R_SUCCESS);
	RUNTIME_CHECK(isc_mutex_init(&contextslock) == ISC_R_SUCCESS);
	ISC_LIST_INIT(contexts);
	totallost = 0;
}

/*
 * Public.
 */

isc_result_t
isc_mem_createx(size_t init_max_size, size_t target_size,
		 isc_memalloc_t memalloc, isc_memfree_t memfree, void *arg,
		 isc_mem_t **ctxp)
{
	return (isc_mem_createx2(init_max_size, target_size, memalloc, memfree,
				 arg, ctxp, isc_mem_defaultflags));

}

isc_result_t
isc_mem_createx2(size_t init_max_size, size_t target_size,
		  isc_memalloc_t memalloc, isc_memfree_t memfree, void *arg,
		  isc_mem_t **ctxp, unsigned int flags)
{
	isc__mem_t *ctx;
	isc_result_t result;

	REQUIRE(ctxp != NULL && *ctxp == NULL);
	REQUIRE(memalloc != NULL);
	REQUIRE(memfree != NULL);

	INSIST((ALIGNMENT_SIZE & (ALIGNMENT_SIZE - 1)) == 0);

	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);

	ctx = (memalloc)(arg, sizeof(*ctx));
	if (ctx == NULL)
		return (ISC_R_NOMEMORY);

	if ((flags & ISC_MEMFLAG_NOLOCK) == 0) {
		result = isc_mutex_init(&ctx->lock);
		if (result != ISC_R_SUCCESS) {
			(memfree)(arg, ctx);
			return (result);
		}
	}

	if (init_max_size == 0U)
		ctx->max_size = DEF_MAX_SIZE;
	else
		ctx->max_size = init_max_size;
	ctx->flags = flags;
	ctx->references = 1;
	memset(ctx->name, 0, sizeof(ctx->name));
	ctx->tag = NULL;
	ctx->quota = 0;
	ctx->total = 0;
	ctx->inuse = 0;
	ctx->maxinuse = 0;
	ctx->hi_water = 0;
	ctx->lo_water = 0;
	ctx->hi_called = false;
	ctx->is_overmem = false;
	ctx->water = NULL;
	ctx->water_arg = NULL;
	ctx->common.impmagic = MEM_MAGIC;
	ctx->common.magic = ISCAPI_MCTX_MAGIC;
	ctx->common.methods = (isc_memmethods_t *)&memmethods;
	isc_ondestroy_init(&ctx->ondestroy);
	ctx->memalloc = memalloc;
	ctx->memfree = memfree;
	ctx->arg = arg;
	ctx->stats = NULL;
	ctx->checkfree = true;
#if ISC_MEM_TRACKLINES
	ctx->debuglist = NULL;
	ctx->debuglistcnt = 0;
#endif
	ISC_LIST_INIT(ctx->pools);
	ctx->poolcnt = 0;
	ctx->freelists = NULL;
	ctx->basic_blocks = NULL;
	ctx->basic_table = NULL;
	ctx->basic_table_count = 0;
	ctx->basic_table_size = 0;
	ctx->lowest = NULL;
	ctx->highest = NULL;

	ctx->stats = (memalloc)(arg,
				(ctx->max_size+1) * sizeof(struct stats));
	if (ctx->stats == NULL) {
		result = ISC_R_NOMEMORY;
		goto error;
	}
	memset(ctx->stats, 0, (ctx->max_size + 1) * sizeof(struct stats));

	if ((flags & ISC_MEMFLAG_INTERNAL) != 0) {
		if (target_size == 0U)
			ctx->mem_target = DEF_MEM_TARGET;
		else
			ctx->mem_target = target_size;
		ctx->freelists = (memalloc)(arg, ctx->max_size *
						 sizeof(element *));
		if (ctx->freelists == NULL) {
			result = ISC_R_NOMEMORY;
			goto error;
		}
		memset(ctx->freelists, 0,
		       ctx->max_size * sizeof(element *));
	}

#if ISC_MEM_TRACKLINES
	if ((isc_mem_debugging & ISC_MEM_DEBUGRECORD) != 0) {
		unsigned int i;

		ctx->debuglist = (memalloc)(arg,
				      (ctx->max_size+1) * sizeof(debuglist_t));
		if (ctx->debuglist == NULL) {
			result = ISC_R_NOMEMORY;
			goto error;
		}
		for (i = 0; i <= ctx->max_size; i++)
			ISC_LIST_INIT(ctx->debuglist[i]);
	}
#endif

	ctx->memalloc_failures = 0;

	LOCK(&contextslock);
	ISC_LIST_INITANDAPPEND(contexts, ctx, link);
	UNLOCK(&contextslock);

	*ctxp = (isc_mem_t *)ctx;
	return (ISC_R_SUCCESS);

  error:
	if (ctx != NULL) {
		if (ctx->stats != NULL)
			(memfree)(arg, ctx->stats);
		if (ctx->freelists != NULL)
			(memfree)(arg, ctx->freelists);
#if ISC_MEM_TRACKLINES
		if (ctx->debuglist != NULL)
			(ctx->memfree)(ctx->arg, ctx->debuglist);
#endif /* ISC_MEM_TRACKLINES */
		if ((ctx->flags & ISC_MEMFLAG_NOLOCK) == 0)
			DESTROYLOCK(&ctx->lock);
		(memfree)(arg, ctx);
	}

	return (result);
}

static void
destroy(isc__mem_t *ctx) {
	unsigned int i;
	isc_ondestroy_t ondest;

	LOCK(&contextslock);
	ISC_LIST_UNLINK(contexts, ctx, link);
	totallost += ctx->inuse;
	UNLOCK(&contextslock);

	ctx->common.impmagic = 0;
	ctx->common.magic = 0;

	INSIST(ISC_LIST_EMPTY(ctx->pools));

#if ISC_MEM_TRACKLINES
	if (ctx->debuglist != NULL) {
		if (ctx->checkfree) {
			for (i = 0; i <= ctx->max_size; i++) {
				if (!ISC_LIST_EMPTY(ctx->debuglist[i]))
					print_active(ctx, stderr);
				INSIST(ISC_LIST_EMPTY(ctx->debuglist[i]));
			}
		} else {
			debuglink_t *dl;

			for (i = 0; i <= ctx->max_size; i++)
				for (dl = ISC_LIST_HEAD(ctx->debuglist[i]);
				     dl != NULL;
				     dl = ISC_LIST_HEAD(ctx->debuglist[i])) {
					ISC_LIST_UNLINK(ctx->debuglist[i],
							dl, link);
					free(dl);
				}
		}
		(ctx->memfree)(ctx->arg, ctx->debuglist);
	}
#endif
	INSIST(ctx->references == 0);

	if (ctx->checkfree) {
		for (i = 0; i <= ctx->max_size; i++) {
			if (ctx->stats[i].gets != 0U) {
				fprintf(stderr,
					"Failing assertion due to probable "
					"leaked memory in context %p (\"%s\") "
					"(stats[%u].gets == %lu).\n",
					ctx, ctx->name, i, ctx->stats[i].gets);
#if ISC_MEM_TRACKLINES
				print_active(ctx, stderr);
#endif
				INSIST(ctx->stats[i].gets == 0U);
			}
		}
	}

	(ctx->memfree)(ctx->arg, ctx->stats);

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		for (i = 0; i < ctx->basic_table_count; i++)
			(ctx->memfree)(ctx->arg, ctx->basic_table[i]);
		(ctx->memfree)(ctx->arg, ctx->freelists);
		if (ctx->basic_table != NULL)
			(ctx->memfree)(ctx->arg, ctx->basic_table);
	}

	ondest = ctx->ondestroy;

	if ((ctx->flags & ISC_MEMFLAG_NOLOCK) == 0)
		DESTROYLOCK(&ctx->lock);
	(ctx->memfree)(ctx->arg, ctx);

	isc_ondestroy_notify(&ondest, ctx);
}

void
isc__mem_attach(isc_mem_t *source0, isc_mem_t **targetp) {
	isc__mem_t *source = (isc__mem_t *)source0;

	REQUIRE(VALID_CONTEXT(source));
	REQUIRE(targetp != NULL && *targetp == NULL);

	MCTXLOCK(source, &source->lock);
	source->references++;
	MCTXUNLOCK(source, &source->lock);

	*targetp = (isc_mem_t *)source;
}

void
isc__mem_detach(isc_mem_t **ctxp) {
	isc__mem_t *ctx;
	bool want_destroy = false;

	REQUIRE(ctxp != NULL);
	ctx = (isc__mem_t *)*ctxp;
	REQUIRE(VALID_CONTEXT(ctx));

	MCTXLOCK(ctx, &ctx->lock);
	INSIST(ctx->references > 0);
	ctx->references--;
	if (ctx->references == 0)
		want_destroy = true;
	MCTXUNLOCK(ctx, &ctx->lock);

	if (want_destroy)
		destroy(ctx);

	*ctxp = NULL;
}

/*
 * isc_mem_putanddetach() is the equivalent of:
 *
 * mctx = NULL;
 * isc_mem_attach(ptr->mctx, &mctx);
 * isc_mem_detach(&ptr->mctx);
 * isc_mem_put(mctx, ptr, sizeof(*ptr);
 * isc_mem_detach(&mctx);
 */

void
isc___mem_putanddetach(isc_mem_t **ctxp, void *ptr, size_t size FLARG) {
	isc__mem_t *ctx;
	bool want_destroy = false;
	size_info *si;
	size_t oldsize;

	REQUIRE(ctxp != NULL);
	ctx = (isc__mem_t *)*ctxp;
	REQUIRE(VALID_CONTEXT(ctx));
	REQUIRE(ptr != NULL);

	/*
	 * Must be before mem_putunlocked() as ctxp is usually within
	 * [ptr..ptr+size).
	 */
	*ctxp = NULL;

	if ((isc_mem_debugging & (ISC_MEM_DEBUGSIZE|ISC_MEM_DEBUGCTX)) != 0) {
		if ((isc_mem_debugging & ISC_MEM_DEBUGSIZE) != 0) {
			si = &(((size_info *)ptr)[-1]);
			oldsize = si->u.size - ALIGNMENT_SIZE;
			if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0)
				oldsize -= ALIGNMENT_SIZE;
			INSIST(oldsize == size);
		}
		isc__mem_free((isc_mem_t *)ctx, ptr FLARG_PASS);

		MCTXLOCK(ctx, &ctx->lock);
		ctx->references--;
		if (ctx->references == 0)
			want_destroy = true;
		MCTXUNLOCK(ctx, &ctx->lock);
		if (want_destroy)
			destroy(ctx);

		return;
	}

	MCTXLOCK(ctx, &ctx->lock);

	DELETE_TRACE(ctx, ptr, size, file, line);

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		mem_putunlocked(ctx, ptr, size);
	} else {
		mem_putstats(ctx, ptr, size);
		mem_put(ctx, ptr, size);
	}

	INSIST(ctx->references > 0);
	ctx->references--;
	if (ctx->references == 0)
		want_destroy = true;

	MCTXUNLOCK(ctx, &ctx->lock);

	if (want_destroy)
		destroy(ctx);
}

void
isc__mem_destroy(isc_mem_t **ctxp) {
	isc__mem_t *ctx;

	/*
	 * This routine provides legacy support for callers who use mctxs
	 * without attaching/detaching.
	 */

	REQUIRE(ctxp != NULL);
	ctx = (isc__mem_t *)*ctxp;
	REQUIRE(VALID_CONTEXT(ctx));

	MCTXLOCK(ctx, &ctx->lock);
#if ISC_MEM_TRACKLINES
	if (ctx->references != 1)
		print_active(ctx, stderr);
#endif
	REQUIRE(ctx->references == 1);
	ctx->references--;
	MCTXUNLOCK(ctx, &ctx->lock);

	destroy(ctx);

	*ctxp = NULL;
}

isc_result_t
isc_mem_ondestroy(isc_mem_t *ctx0, isc_task_t *task, isc_event_t **event) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	isc_result_t res;

	MCTXLOCK(ctx, &ctx->lock);
	res = isc_ondestroy_register(&ctx->ondestroy, task, event);
	MCTXUNLOCK(ctx, &ctx->lock);

	return (res);
}

void *
isc___mem_get(isc_mem_t *ctx0, size_t size FLARG) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	void *ptr;
	bool call_water = false;

	REQUIRE(VALID_CONTEXT(ctx));

	if ((isc_mem_debugging & (ISC_MEM_DEBUGSIZE|ISC_MEM_DEBUGCTX)) != 0)
		return (isc__mem_allocate(ctx0, size FLARG_PASS));

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		MCTXLOCK(ctx, &ctx->lock);
		ptr = mem_getunlocked(ctx, size);
	} else {
		ptr = mem_get(ctx, size);
		MCTXLOCK(ctx, &ctx->lock);
		if (ptr != NULL)
			mem_getstats(ctx, size);
	}

	ADD_TRACE(ctx, ptr, size, file, line);
	if (ctx->hi_water != 0U && ctx->inuse > ctx->hi_water) {
		ctx->is_overmem = true;
		if (!ctx->hi_called)
			call_water = true;
	}
	if (ctx->inuse > ctx->maxinuse) {
		ctx->maxinuse = ctx->inuse;
		if (ctx->hi_water != 0U && ctx->inuse > ctx->hi_water &&
		    (isc_mem_debugging & ISC_MEM_DEBUGUSAGE) != 0)
			fprintf(stderr, "maxinuse = %lu\n",
				(unsigned long)ctx->inuse);
	}
	MCTXUNLOCK(ctx, &ctx->lock);

	if (call_water && (ctx->water != NULL))
		(ctx->water)(ctx->water_arg, ISC_MEM_HIWATER);

	return (ptr);
}

void
isc___mem_put(isc_mem_t *ctx0, void *ptr, size_t size FLARG) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	bool call_water = false;
	size_info *si;
	size_t oldsize;

	REQUIRE(VALID_CONTEXT(ctx));
	REQUIRE(ptr != NULL);

	if ((isc_mem_debugging & (ISC_MEM_DEBUGSIZE|ISC_MEM_DEBUGCTX)) != 0) {
		if ((isc_mem_debugging & ISC_MEM_DEBUGSIZE) != 0) {
			si = &(((size_info *)ptr)[-1]);
			oldsize = si->u.size - ALIGNMENT_SIZE;
			if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0)
				oldsize -= ALIGNMENT_SIZE;
			INSIST(oldsize == size);
		}
		isc__mem_free((isc_mem_t *)ctx, ptr FLARG_PASS);
		return;
	}

	MCTXLOCK(ctx, &ctx->lock);

	DELETE_TRACE(ctx, ptr, size, file, line);

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		mem_putunlocked(ctx, ptr, size);
	} else {
		mem_putstats(ctx, ptr, size);
		mem_put(ctx, ptr, size);
	}

	/*
	 * The check against ctx->lo_water == 0 is for the condition
	 * when the context was pushed over hi_water but then had
	 * isc_mem_setwater() called with 0 for hi_water and lo_water.
	 */
	if ((ctx->inuse < ctx->lo_water) || (ctx->lo_water == 0U)) {
		ctx->is_overmem = false;
		if (ctx->hi_called)
			call_water = true;
	}

	MCTXUNLOCK(ctx, &ctx->lock);

	if (call_water && (ctx->water != NULL))
		(ctx->water)(ctx->water_arg, ISC_MEM_LOWATER);
}

void
isc__mem_waterack(isc_mem_t *ctx0, int flag) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;

	REQUIRE(VALID_CONTEXT(ctx));

	MCTXLOCK(ctx, &ctx->lock);
	if (flag == ISC_MEM_LOWATER)
		ctx->hi_called = false;
	else if (flag == ISC_MEM_HIWATER)
		ctx->hi_called = true;
	MCTXUNLOCK(ctx, &ctx->lock);
}

#if ISC_MEM_TRACKLINES
static void
print_active(isc__mem_t *mctx, FILE *out) {
	if (mctx->debuglist != NULL) {
		debuglink_t *dl;
		unsigned int i, j;
		const char *format;
		bool found;

		fprintf(out, "%s", isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
					    ISC_MSG_DUMPALLOC,
					    "Dump of all outstanding "
					    "memory allocations:\n"));
		found = false;
		format = isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
					ISC_MSG_PTRFILELINE,
					"\tptr %p size %u file %s line %u\n");
		for (i = 0; i <= mctx->max_size; i++) {
			dl = ISC_LIST_HEAD(mctx->debuglist[i]);

			if (dl != NULL)
				found = true;

			while (dl != NULL) {
				for (j = 0; j < DEBUGLIST_COUNT; j++)
					if (dl->ptr[j] != NULL)
						fprintf(out, format,
							dl->ptr[j],
							dl->size[j],
							dl->file[j],
							dl->line[j]);
				dl = ISC_LIST_NEXT(dl, link);
			}
		}
		if (!found)
			fputs(isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
					     ISC_MSG_NONE, "\tNone.\n"), out);
	}
}
#endif

/*
 * Print the stats[] on the stream "out" with suitable formatting.
 */
void
isc_mem_stats(isc_mem_t *ctx0, FILE *out) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	size_t i;
	const struct stats *s;
	const isc__mempool_t *pool;

	REQUIRE(VALID_CONTEXT(ctx));
	MCTXLOCK(ctx, &ctx->lock);

	for (i = 0; i <= ctx->max_size; i++) {
		s = &ctx->stats[i];

		if (s->totalgets == 0U && s->gets == 0U)
			continue;
		fprintf(out, "%s%5lu: %11lu gets, %11lu rem",
			(i == ctx->max_size) ? ">=" : "  ",
			(unsigned long) i, s->totalgets, s->gets);
		if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0 &&
		    (s->blocks != 0U || s->freefrags != 0U))
			fprintf(out, " (%lu bl, %lu ff)",
				s->blocks, s->freefrags);
		fputc('\n', out);
	}

	/*
	 * Note that since a pool can be locked now, these stats might be
	 * somewhat off if the pool is in active use at the time the stats
	 * are dumped.  The link fields are protected by the isc_mem_t's
	 * lock, however, so walking this list and extracting integers from
	 * stats fields is always safe.
	 */
	pool = ISC_LIST_HEAD(ctx->pools);
	if (pool != NULL) {
		fprintf(out, "%s", isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
					    ISC_MSG_POOLSTATS,
					    "[Pool statistics]\n"));
		fprintf(out, "%15s %10s %10s %10s %10s %10s %10s %10s %1s\n",
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLNAME, "name"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLSIZE, "size"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLMAXALLOC, "maxalloc"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLALLOCATED, "allocated"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLFREECOUNT, "freecount"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLFREEMAX, "freemax"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLFILLCOUNT, "fillcount"),
			isc_msgcat_get(isc_msgcat, ISC_MSGSET_MEM,
				       ISC_MSG_POOLGETS, "gets"),
			"L");
	}
	while (pool != NULL) {
		fprintf(out, "%15s %10lu %10u %10u %10u %10u %10u %10u %s\n",
#if ISC_MEMPOOL_NAMES
			pool->name,
#else
			"(not tracked)",
#endif
			(unsigned long) pool->size, pool->maxalloc,
			pool->allocated, pool->freecount, pool->freemax,
			pool->fillcount, pool->gets,
			(pool->lock == NULL ? "N" : "Y"));
		pool = ISC_LIST_NEXT(pool, link);
	}

#if ISC_MEM_TRACKLINES
	print_active(ctx, out);
#endif

	MCTXUNLOCK(ctx, &ctx->lock);
}

/*
 * Replacements for malloc() and free() -- they implicitly remember the
 * size of the object allocated (with some additional overhead).
 */

static void *
mem_allocateunlocked(isc_mem_t *ctx0, size_t size) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	size_info *si;

	size += ALIGNMENT_SIZE;
	if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0)
		size += ALIGNMENT_SIZE;

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0)
		si = mem_getunlocked(ctx, size);
	else
		si = mem_get(ctx, size);

	if (si == NULL)
		return (NULL);
	if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0) {
		si->u.ctx = ctx;
		si++;
	}
	si->u.size = size;
	return (&si[1]);
}

void *
isc___mem_allocate(isc_mem_t *ctx0, size_t size FLARG) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	size_info *si;
	bool call_water = false;

	REQUIRE(VALID_CONTEXT(ctx));

	MCTXLOCK(ctx, &ctx->lock);
	si = mem_allocateunlocked((isc_mem_t *)ctx, size);
	if (((ctx->flags & ISC_MEMFLAG_INTERNAL) == 0) && (si != NULL))
		mem_getstats(ctx, si[-1].u.size);

	ADD_TRACE(ctx, si, si[-1].u.size, file, line);
	if (ctx->hi_water != 0U && ctx->inuse > ctx->hi_water &&
	    !ctx->is_overmem) {
		ctx->is_overmem = true;
	}

	if (ctx->hi_water != 0U && !ctx->hi_called &&
	    ctx->inuse > ctx->hi_water) {
		ctx->hi_called = true;
		call_water = true;
	}
	if (ctx->inuse > ctx->maxinuse) {
		ctx->maxinuse = ctx->inuse;
		if (ctx->hi_water != 0U && ctx->inuse > ctx->hi_water &&
		    (isc_mem_debugging & ISC_MEM_DEBUGUSAGE) != 0)
			fprintf(stderr, "maxinuse = %lu\n",
				(unsigned long)ctx->inuse);
	}
	MCTXUNLOCK(ctx, &ctx->lock);

	if (call_water)
		(ctx->water)(ctx->water_arg, ISC_MEM_HIWATER);

	return (si);
}

void *
isc___mem_reallocate(isc_mem_t *ctx0, void *ptr, size_t size FLARG) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	void *new_ptr = NULL;
	size_t oldsize, copysize;

	REQUIRE(VALID_CONTEXT(ctx));

	/*
	 * This function emulates the realloc(3) standard library function:
	 * - if size > 0, allocate new memory; and if ptr is non NULL, copy
	 *   as much of the old contents to the new buffer and free the old one.
	 *   Note that when allocation fails the original pointer is intact;
	 *   the caller must free it.
	 * - if size is 0 and ptr is non NULL, simply free the given ptr.
	 * - this function returns:
	 *     pointer to the newly allocated memory, or
	 *     NULL if allocation fails or doesn't happen.
	 */
	if (size > 0U) {
		new_ptr = isc__mem_allocate(ctx0, size FLARG_PASS);
		if (new_ptr != NULL && ptr != NULL) {
			oldsize = (((size_info *)ptr)[-1]).u.size;
			INSIST(oldsize >= ALIGNMENT_SIZE);
			oldsize -= ALIGNMENT_SIZE;
			if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0) {
				INSIST(oldsize >= ALIGNMENT_SIZE);
				oldsize -= ALIGNMENT_SIZE;
			}
			copysize = (oldsize > size) ? size : oldsize;
			memmove(new_ptr, ptr, copysize);
			isc__mem_free(ctx0, ptr FLARG_PASS);
		}
	} else if (ptr != NULL)
		isc__mem_free(ctx0, ptr FLARG_PASS);

	return (new_ptr);
}

void
isc___mem_free(isc_mem_t *ctx0, void *ptr FLARG) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	size_info *si;
	size_t size;
	bool call_water= false;

	REQUIRE(VALID_CONTEXT(ctx));
	REQUIRE(ptr != NULL);

	if ((isc_mem_debugging & ISC_MEM_DEBUGCTX) != 0) {
		si = &(((size_info *)ptr)[-2]);
		REQUIRE(si->u.ctx == ctx);
		size = si[1].u.size;
	} else {
		si = &(((size_info *)ptr)[-1]);
		size = si->u.size;
	}

	MCTXLOCK(ctx, &ctx->lock);

	DELETE_TRACE(ctx, ptr, size, file, line);

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		mem_putunlocked(ctx, si, size);
	} else {
		mem_putstats(ctx, si, size);
		mem_put(ctx, si, size);
	}

	/*
	 * The check against ctx->lo_water == 0 is for the condition
	 * when the context was pushed over hi_water but then had
	 * isc_mem_setwater() called with 0 for hi_water and lo_water.
	 */
	if (ctx->is_overmem &&
	    (ctx->inuse < ctx->lo_water || ctx->lo_water == 0U)) {
		ctx->is_overmem = false;
	}

	if (ctx->hi_called &&
	    (ctx->inuse < ctx->lo_water || ctx->lo_water == 0U)) {
		ctx->hi_called = false;

		if (ctx->water != NULL)
			call_water = true;
	}
	MCTXUNLOCK(ctx, &ctx->lock);

	if (call_water)
		(ctx->water)(ctx->water_arg, ISC_MEM_LOWATER);
}


/*
 * Other useful things.
 */

char *
isc___mem_strdup(isc_mem_t *mctx0, const char *s FLARG) {
	isc__mem_t *mctx = (isc__mem_t *)mctx0;
	size_t len;
	char *ns;

	REQUIRE(VALID_CONTEXT(mctx));
	REQUIRE(s != NULL);

	len = strlen(s) + 1;

	ns = isc__mem_allocate((isc_mem_t *)mctx, len FLARG_PASS);

	if (ns != NULL)
		strlcpy(ns, s, len);

	return (ns);
}

void
isc__mem_setdestroycheck(isc_mem_t *ctx0, bool flag) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;

	REQUIRE(VALID_CONTEXT(ctx));
	MCTXLOCK(ctx, &ctx->lock);

	ctx->checkfree = flag;

	MCTXUNLOCK(ctx, &ctx->lock);
}

/*
 * Quotas
 */

void
isc_mem_setquota(isc_mem_t *ctx0, size_t quota) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;

	REQUIRE(VALID_CONTEXT(ctx));
	MCTXLOCK(ctx, &ctx->lock);

	ctx->quota = quota;

	MCTXUNLOCK(ctx, &ctx->lock);
}

size_t
isc_mem_getquota(isc_mem_t *ctx0) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	size_t quota;

	REQUIRE(VALID_CONTEXT(ctx));
	MCTXLOCK(ctx, &ctx->lock);

	quota = ctx->quota;

	MCTXUNLOCK(ctx, &ctx->lock);

	return (quota);
}

size_t
isc__mem_inuse(isc_mem_t *ctx0) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	size_t inuse;

	REQUIRE(VALID_CONTEXT(ctx));
	MCTXLOCK(ctx, &ctx->lock);

	inuse = ctx->inuse;

	MCTXUNLOCK(ctx, &ctx->lock);

	return (inuse);
}

size_t
isc__mem_maxinuse(isc_mem_t *ctx0) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	size_t maxinuse;

	REQUIRE(VALID_CONTEXT(ctx));
	MCTXLOCK(ctx, &ctx->lock);

	maxinuse = ctx->maxinuse;

	MCTXUNLOCK(ctx, &ctx->lock);

	return (maxinuse);
}

size_t
isc__mem_total(isc_mem_t *ctx0) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	size_t total;

	REQUIRE(VALID_CONTEXT(ctx));
	MCTXLOCK(ctx, &ctx->lock);

	total = ctx->total;

	MCTXUNLOCK(ctx, &ctx->lock);

	return (total);
}

void
isc__mem_setwater(isc_mem_t *ctx0, isc_mem_water_t water, void *water_arg,
		  size_t hiwater, size_t lowater)
{
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	bool callwater = false;
	isc_mem_water_t oldwater;
	void *oldwater_arg;

	REQUIRE(VALID_CONTEXT(ctx));
	REQUIRE(hiwater >= lowater);

	MCTXLOCK(ctx, &ctx->lock);
	oldwater = ctx->water;
	oldwater_arg = ctx->water_arg;
	if (water == NULL) {
		callwater = ctx->hi_called;
		ctx->water = NULL;
		ctx->water_arg = NULL;
		ctx->hi_water = 0;
		ctx->lo_water = 0;
	} else {
		if (ctx->hi_called &&
		    (ctx->water != water || ctx->water_arg != water_arg ||
		     ctx->inuse < lowater || lowater == 0U))
			callwater = true;
		ctx->water = water;
		ctx->water_arg = water_arg;
		ctx->hi_water = hiwater;
		ctx->lo_water = lowater;
	}
	MCTXUNLOCK(ctx, &ctx->lock);

	if (callwater && oldwater != NULL)
		(oldwater)(oldwater_arg, ISC_MEM_LOWATER);
}

bool
isc__mem_isovermem(isc_mem_t *ctx0) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;

	REQUIRE(VALID_CONTEXT(ctx));

	/*
	 * We don't bother to lock the context because 100% accuracy isn't
	 * necessary (and even if we locked the context the returned value
	 * could be different from the actual state when it's used anyway)
	 */
	return (ctx->is_overmem);
}

void
isc_mem_setname(isc_mem_t *ctx0, const char *name, void *tag) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;

	REQUIRE(VALID_CONTEXT(ctx));

	LOCK(&ctx->lock);
	strlcpy(ctx->name, name, sizeof(ctx->name));
	ctx->tag = tag;
	UNLOCK(&ctx->lock);
}

const char *
isc_mem_getname(isc_mem_t *ctx0) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;

	REQUIRE(VALID_CONTEXT(ctx));

	if (ctx->name[0] == 0)
		return ("");

	return (ctx->name);
}

void *
isc_mem_gettag(isc_mem_t *ctx0) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;

	REQUIRE(VALID_CONTEXT(ctx));

	return (ctx->tag);
}

/*
 * Memory pool stuff
 */

isc_result_t
isc__mempool_create(isc_mem_t *mctx0, size_t size, isc_mempool_t **mpctxp) {
	isc__mem_t *mctx = (isc__mem_t *)mctx0;
	isc__mempool_t *mpctx;

	REQUIRE(VALID_CONTEXT(mctx));
	REQUIRE(size > 0U);
	REQUIRE(mpctxp != NULL && *mpctxp == NULL);

	/*
	 * Allocate space for this pool, initialize values, and if all works
	 * well, attach to the memory context.
	 */
	mpctx = isc_mem_get((isc_mem_t *)mctx, sizeof(isc__mempool_t));
	if (mpctx == NULL)
		return (ISC_R_NOMEMORY);

	mpctx->common.methods = (isc_mempoolmethods_t *)&mempoolmethods;
	mpctx->common.impmagic = MEMPOOL_MAGIC;
	mpctx->common.magic = ISCAPI_MPOOL_MAGIC;
	mpctx->lock = NULL;
	mpctx->mctx = mctx;
	/*
	 * Mempools are stored as a linked list of element.
	 */
	if (size < sizeof(element)) {
		size = sizeof(element);
	}
	mpctx->size = size;
	mpctx->maxalloc = UINT_MAX;
	mpctx->allocated = 0;
	mpctx->freecount = 0;
	mpctx->freemax = 1;
	mpctx->fillcount = 1;
	mpctx->gets = 0;
#if ISC_MEMPOOL_NAMES
	mpctx->name[0] = 0;
#endif
	mpctx->items = NULL;

	*mpctxp = (isc_mempool_t *)mpctx;

	MCTXLOCK(mctx, &mctx->lock);
	ISC_LIST_INITANDAPPEND(mctx->pools, mpctx, link);
	mctx->poolcnt++;
	MCTXUNLOCK(mctx, &mctx->lock);

	return (ISC_R_SUCCESS);
}

void
isc__mempool_setname(isc_mempool_t *mpctx0, const char *name) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;

	REQUIRE(name != NULL);
	REQUIRE(VALID_MEMPOOL(mpctx));

#if ISC_MEMPOOL_NAMES
	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	strlcpy(mpctx->name, name, sizeof(mpctx->name));

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);
#else
	UNUSED(mpctx);
	UNUSED(name);
#endif
}

void
isc__mempool_destroy(isc_mempool_t **mpctxp) {
	isc__mempool_t *mpctx;
	isc__mem_t *mctx;
	isc_mutex_t *lock;
	element *item;

	REQUIRE(mpctxp != NULL);
	mpctx = (isc__mempool_t *)*mpctxp;
	REQUIRE(VALID_MEMPOOL(mpctx));
#if ISC_MEMPOOL_NAMES
	if (mpctx->allocated > 0)
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc__mempool_destroy(): mempool %s "
				 "leaked memory",
				 mpctx->name);
#endif
	REQUIRE(mpctx->allocated == 0);

	mctx = mpctx->mctx;

	lock = mpctx->lock;

	if (lock != NULL)
		LOCK(lock);

	/*
	 * Return any items on the free list
	 */
	MCTXLOCK(mctx, &mctx->lock);
	while (mpctx->items != NULL) {
		INSIST(mpctx->freecount > 0);
		mpctx->freecount--;
		item = mpctx->items;
		mpctx->items = item->next;

		if ((mctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
			mem_putunlocked(mctx, item, mpctx->size);
		} else {
			mem_putstats(mctx, item, mpctx->size);
			mem_put(mctx, item, mpctx->size);
		}
	}
	MCTXUNLOCK(mctx, &mctx->lock);

	/*
	 * Remove our linked list entry from the memory context.
	 */
	MCTXLOCK(mctx, &mctx->lock);
	ISC_LIST_UNLINK(mctx->pools, mpctx, link);
	mctx->poolcnt--;
	MCTXUNLOCK(mctx, &mctx->lock);

	mpctx->common.impmagic = 0;
	mpctx->common.magic = 0;

	isc_mem_put((isc_mem_t *)mpctx->mctx, mpctx, sizeof(isc__mempool_t));

	if (lock != NULL)
		UNLOCK(lock);

	*mpctxp = NULL;
}

void
isc__mempool_associatelock(isc_mempool_t *mpctx0, isc_mutex_t *lock) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;

	REQUIRE(VALID_MEMPOOL(mpctx));
	REQUIRE(mpctx->lock == NULL);
	REQUIRE(lock != NULL);

	mpctx->lock = lock;
}

void *
isc___mempool_get(isc_mempool_t *mpctx0 FLARG) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;
	element *item;
	isc__mem_t *mctx;
	unsigned int i;

	REQUIRE(VALID_MEMPOOL(mpctx));

	mctx = mpctx->mctx;

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	/*
	 * Don't let the caller go over quota
	 */
	if (ISC_UNLIKELY(mpctx->allocated >= mpctx->maxalloc)) {
		item = NULL;
		goto out;
	}

	if (ISC_UNLIKELY(mpctx->items == NULL)) {
		/*
		 * We need to dip into the well.  Lock the memory context
		 * here and fill up our free list.
		 */
		MCTXLOCK(mctx, &mctx->lock);
		for (i = 0; i < mpctx->fillcount; i++) {
			if ((mctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
				item = mem_getunlocked(mctx, mpctx->size);
			} else {
				item = mem_get(mctx, mpctx->size);
				if (item != NULL)
					mem_getstats(mctx, mpctx->size);
			}
			if (ISC_UNLIKELY(item == NULL))
				break;
			item->next = mpctx->items;
			mpctx->items = item;
			mpctx->freecount++;
		}
		MCTXUNLOCK(mctx, &mctx->lock);
	}

	/*
	 * If we didn't get any items, return NULL.
	 */
	item = mpctx->items;
	if (ISC_UNLIKELY(item == NULL))
		goto out;

	mpctx->items = item->next;
	INSIST(mpctx->freecount > 0);
	mpctx->freecount--;
	mpctx->gets++;
	mpctx->allocated++;

 out:
	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);

#if ISC_MEM_TRACKLINES
	if (((isc_mem_debugging & TRACE_OR_RECORD) != 0) && item != NULL) {
		MCTXLOCK(mctx, &mctx->lock);
		ADD_TRACE(mctx, item, mpctx->size, file, line);
		MCTXUNLOCK(mctx, &mctx->lock);
	}
#endif /* ISC_MEM_TRACKLINES */

	return (item);
}

/* coverity[+free : arg-1] */
void
isc___mempool_put(isc_mempool_t *mpctx0, void *mem FLARG) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;
	isc__mem_t *mctx;
	element *item;

	REQUIRE(VALID_MEMPOOL(mpctx));
	REQUIRE(mem != NULL);

	mctx = mpctx->mctx;

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	INSIST(mpctx->allocated > 0);
	mpctx->allocated--;

#if ISC_MEM_TRACKLINES
	if ((isc_mem_debugging & TRACE_OR_RECORD) != 0) {
		MCTXLOCK(mctx, &mctx->lock);
		DELETE_TRACE(mctx, mem, mpctx->size, file, line);
		MCTXUNLOCK(mctx, &mctx->lock);
	}
#endif /* ISC_MEM_TRACKLINES */

	/*
	 * If our free list is full, return this to the mctx directly.
	 */
	if (mpctx->freecount >= mpctx->freemax) {
		MCTXLOCK(mctx, &mctx->lock);
		if ((mctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
			mem_putunlocked(mctx, mem, mpctx->size);
		} else {
			mem_putstats(mctx, mem, mpctx->size);
			mem_put(mctx, mem, mpctx->size);
		}
		MCTXUNLOCK(mctx, &mctx->lock);
		if (mpctx->lock != NULL)
			UNLOCK(mpctx->lock);
		return;
	}

	/*
	 * Otherwise, attach it to our free list and bump the counter.
	 */
	mpctx->freecount++;
	item = (element *)mem;
	item->next = mpctx->items;
	mpctx->items = item;

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);
}

/*
 * Quotas
 */

void
isc__mempool_setfreemax(isc_mempool_t *mpctx0, unsigned int limit) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;

	REQUIRE(VALID_MEMPOOL(mpctx));

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	mpctx->freemax = limit;

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);
}

unsigned int
isc_mempool_getfreemax(isc_mempool_t *mpctx0) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;
	unsigned int freemax;

	REQUIRE(VALID_MEMPOOL(mpctx));

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	freemax = mpctx->freemax;

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);

	return (freemax);
}

unsigned int
isc_mempool_getfreecount(isc_mempool_t *mpctx0) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;
	unsigned int freecount;

	REQUIRE(VALID_MEMPOOL(mpctx));

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	freecount = mpctx->freecount;

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);

	return (freecount);
}

void
isc__mempool_setmaxalloc(isc_mempool_t *mpctx0, unsigned int limit) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;

	REQUIRE(limit > 0);

	REQUIRE(VALID_MEMPOOL(mpctx));

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	mpctx->maxalloc = limit;

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);
}

unsigned int
isc_mempool_getmaxalloc(isc_mempool_t *mpctx0) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;
	unsigned int maxalloc;

	REQUIRE(VALID_MEMPOOL(mpctx));

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	maxalloc = mpctx->maxalloc;

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);

	return (maxalloc);
}

unsigned int
isc__mempool_getallocated(isc_mempool_t *mpctx0) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;
	unsigned int allocated;

	REQUIRE(VALID_MEMPOOL(mpctx));

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	allocated = mpctx->allocated;

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);

	return (allocated);
}

void
isc__mempool_setfillcount(isc_mempool_t *mpctx0, unsigned int limit) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;

	REQUIRE(limit > 0);
	REQUIRE(VALID_MEMPOOL(mpctx));

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	mpctx->fillcount = limit;

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);
}

unsigned int
isc_mempool_getfillcount(isc_mempool_t *mpctx0) {
	isc__mempool_t *mpctx = (isc__mempool_t *)mpctx0;

	unsigned int fillcount;

	REQUIRE(VALID_MEMPOOL(mpctx));

	if (mpctx->lock != NULL)
		LOCK(mpctx->lock);

	fillcount = mpctx->fillcount;

	if (mpctx->lock != NULL)
		UNLOCK(mpctx->lock);

	return (fillcount);
}

isc_result_t
isc__mem_register(void) {
	return (isc_mem_register(isc_mem_create2));
}

void
isc__mem_printactive(isc_mem_t *ctx0, FILE *file) {
#if ISC_MEM_TRACKLINES
	isc__mem_t *ctx = (isc__mem_t *)ctx0;

	REQUIRE(VALID_CONTEXT(ctx));
	REQUIRE(file != NULL);

	print_active(ctx, file);
#else
	UNUSED(ctx0);
	UNUSED(file);
#endif
}

void
isc_mem_printallactive(FILE *file) {
#if !ISC_MEM_TRACKLINES
	UNUSED(file);
#else
	isc__mem_t *ctx;

	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);

	LOCK(&contextslock);
	for (ctx = ISC_LIST_HEAD(contexts);
	     ctx != NULL;
	     ctx = ISC_LIST_NEXT(ctx, link)) {
		fprintf(file, "context: %p\n", ctx);
		print_active(ctx, file);
	}
	UNLOCK(&contextslock);
#endif
}

void
isc_mem_checkdestroyed(FILE *file) {
#if !ISC_MEM_TRACKLINES
	UNUSED(file);
#endif

	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);

	LOCK(&contextslock);
	if (!ISC_LIST_EMPTY(contexts)) {
#if ISC_MEM_TRACKLINES
		if ((isc_mem_debugging & TRACE_OR_RECORD) != 0) {
			isc__mem_t *ctx;

			for (ctx = ISC_LIST_HEAD(contexts);
			     ctx != NULL;
			     ctx = ISC_LIST_NEXT(ctx, link)) {
				fprintf(file, "context: %p\n", ctx);
				print_active(ctx, file);
			}
			fflush(file);
		}
#endif
		INSIST(0);
		ISC_UNREACHABLE();
	}
	UNLOCK(&contextslock);
}

unsigned int
isc_mem_references(isc_mem_t *ctx0) {
	isc__mem_t *ctx = (isc__mem_t *)ctx0;
	unsigned int references;

	REQUIRE(VALID_CONTEXT(ctx));

	MCTXLOCK(ctx, &ctx->lock);
	references = ctx->references;
	MCTXUNLOCK(ctx, &ctx->lock);

	return (references);
}

typedef struct summarystat {
	uint64_t	total;
	uint64_t	inuse;
	uint64_t	blocksize;
	uint64_t	contextsize;
} summarystat_t;

#ifdef HAVE_LIBXML2
#define TRY0(a) do { xmlrc = (a); if (xmlrc < 0) goto error; } while(0)
static int
xml_renderctx(isc__mem_t *ctx, summarystat_t *summary,
	      xmlTextWriterPtr writer)
{
	int xmlrc;

	REQUIRE(VALID_CONTEXT(ctx));

	MCTXLOCK(ctx, &ctx->lock);

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "context"));

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "id"));
	TRY0(xmlTextWriterWriteFormatString(writer, "%p", ctx));
	TRY0(xmlTextWriterEndElement(writer)); /* id */

	if (ctx->name[0] != 0) {
		TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "name"));
		TRY0(xmlTextWriterWriteFormatString(writer, "%s", ctx->name));
		TRY0(xmlTextWriterEndElement(writer)); /* name */
	}

	summary->contextsize += sizeof(*ctx) +
		(ctx->max_size + 1) * sizeof(struct stats) +
		ctx->max_size * sizeof(element *) +
		ctx->basic_table_count * sizeof(char *);
#if ISC_MEM_TRACKLINES
	if (ctx->debuglist != NULL) {
		summary->contextsize +=
			(ctx->max_size + 1) * sizeof(debuglist_t) +
			ctx->debuglistcnt * sizeof(debuglink_t);
	}
#endif
	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "references"));
	TRY0(xmlTextWriterWriteFormatString(writer, "%d", ctx->references));
	TRY0(xmlTextWriterEndElement(writer)); /* references */

	summary->total += ctx->total;
	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "total"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64,
					    (uint64_t)ctx->total));
	TRY0(xmlTextWriterEndElement(writer)); /* total */

	summary->inuse += ctx->inuse;
	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "inuse"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64,
					    (uint64_t)ctx->inuse));
	TRY0(xmlTextWriterEndElement(writer)); /* inuse */

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "maxinuse"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64,
					    (uint64_t)ctx->maxinuse));
	TRY0(xmlTextWriterEndElement(writer)); /* maxinuse */

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "blocksize"));
	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		summary->blocksize += ctx->basic_table_count *
			NUM_BASIC_BLOCKS * ctx->mem_target;
		TRY0(xmlTextWriterWriteFormatString(writer,
					       "%" PRIu64,
					       (uint64_t)
					       ctx->basic_table_count *
					       NUM_BASIC_BLOCKS *
					       ctx->mem_target));
	} else
		TRY0(xmlTextWriterWriteFormatString(writer, "%s", "-"));
	TRY0(xmlTextWriterEndElement(writer)); /* blocksize */

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "pools"));
	TRY0(xmlTextWriterWriteFormatString(writer, "%u", ctx->poolcnt));
	TRY0(xmlTextWriterEndElement(writer)); /* pools */
	summary->contextsize += ctx->poolcnt * sizeof(isc_mempool_t);

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "hiwater"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64,
					    (uint64_t)ctx->hi_water));
	TRY0(xmlTextWriterEndElement(writer)); /* hiwater */

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "lowater"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64 "",
					    (uint64_t)ctx->lo_water));
	TRY0(xmlTextWriterEndElement(writer)); /* lowater */

	TRY0(xmlTextWriterEndElement(writer)); /* context */

 error:
	MCTXUNLOCK(ctx, &ctx->lock);

	return (xmlrc);
}

int
isc_mem_renderxml(xmlTextWriterPtr writer) {
	isc__mem_t *ctx;
	summarystat_t summary;
	uint64_t lost;
	int xmlrc;

	memset(&summary, 0, sizeof(summary));

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "contexts"));

	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);

	LOCK(&contextslock);
	lost = totallost;
	for (ctx = ISC_LIST_HEAD(contexts);
	     ctx != NULL;
	     ctx = ISC_LIST_NEXT(ctx, link)) {
		xmlrc = xml_renderctx(ctx, &summary, writer);
		if (xmlrc < 0) {
			UNLOCK(&contextslock);
			goto error;
		}
	}
	UNLOCK(&contextslock);

	TRY0(xmlTextWriterEndElement(writer)); /* contexts */

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "summary"));

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "TotalUse"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64,
					    summary.total));
	TRY0(xmlTextWriterEndElement(writer)); /* TotalUse */

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "InUse"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64,
					    summary.inuse));
	TRY0(xmlTextWriterEndElement(writer)); /* InUse */

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "BlockSize"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64,
					    summary.blocksize));
	TRY0(xmlTextWriterEndElement(writer)); /* BlockSize */

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "ContextSize"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64,
					    summary.contextsize));
	TRY0(xmlTextWriterEndElement(writer)); /* ContextSize */

	TRY0(xmlTextWriterStartElement(writer, ISC_XMLCHAR "Lost"));
	TRY0(xmlTextWriterWriteFormatString(writer,
					    "%" PRIu64,
					    lost));
	TRY0(xmlTextWriterEndElement(writer)); /* Lost */

	TRY0(xmlTextWriterEndElement(writer)); /* summary */
 error:
	return (xmlrc);
}

#endif /* HAVE_LIBXML2 */

#ifdef HAVE_JSON
#define CHECKMEM(m) do { \
	if (m == NULL) { \
		result = ISC_R_NOMEMORY;\
		goto error;\
	} \
} while(0)

static isc_result_t
json_renderctx(isc__mem_t *ctx, summarystat_t *summary, json_object *array) {
	isc_result_t result = ISC_R_FAILURE;
	json_object *ctxobj, *obj;
	char buf[1024];

	REQUIRE(VALID_CONTEXT(ctx));
	REQUIRE(summary != NULL);
	REQUIRE(array != NULL);

	MCTXLOCK(ctx, &ctx->lock);

	summary->contextsize += sizeof(*ctx) +
		(ctx->max_size + 1) * sizeof(struct stats) +
		ctx->max_size * sizeof(element *) +
		ctx->basic_table_count * sizeof(char *);
	summary->total += ctx->total;
	summary->inuse += ctx->inuse;
	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0)
		summary->blocksize += ctx->basic_table_count *
			NUM_BASIC_BLOCKS * ctx->mem_target;
#if ISC_MEM_TRACKLINES
	if (ctx->debuglist != NULL) {
		summary->contextsize +=
			(ctx->max_size + 1) * sizeof(debuglist_t) +
			ctx->debuglistcnt * sizeof(debuglink_t);
	}
#endif

	ctxobj = json_object_new_object();
	CHECKMEM(ctxobj);

	snprintf(buf, sizeof(buf), "%p", ctx);
	obj = json_object_new_string(buf);
	CHECKMEM(obj);
	json_object_object_add(ctxobj, "id", obj);

	if (ctx->name[0] != 0) {
		obj = json_object_new_string(ctx->name);
		CHECKMEM(obj);
		json_object_object_add(ctxobj, "name", obj);
	}

	obj = json_object_new_int64(ctx->references);
	CHECKMEM(obj);
	json_object_object_add(ctxobj, "references", obj);

	obj = json_object_new_int64(ctx->total);
	CHECKMEM(obj);
	json_object_object_add(ctxobj, "total", obj);

	obj = json_object_new_int64(ctx->inuse);
	CHECKMEM(obj);
	json_object_object_add(ctxobj, "inuse", obj);

	obj = json_object_new_int64(ctx->maxinuse);
	CHECKMEM(obj);
	json_object_object_add(ctxobj, "maxinuse", obj);

	if ((ctx->flags & ISC_MEMFLAG_INTERNAL) != 0) {
		uint64_t blocksize;
		blocksize = ctx->basic_table_count * NUM_BASIC_BLOCKS *
			ctx->mem_target;
		obj = json_object_new_int64(blocksize);
		CHECKMEM(obj);
		json_object_object_add(ctxobj, "blocksize", obj);
	}

	obj = json_object_new_int64(ctx->poolcnt);
	CHECKMEM(obj);
	json_object_object_add(ctxobj, "pools", obj);

	summary->contextsize += ctx->poolcnt * sizeof(isc_mempool_t);

	obj = json_object_new_int64(ctx->hi_water);
	CHECKMEM(obj);
	json_object_object_add(ctxobj, "hiwater", obj);

	obj = json_object_new_int64(ctx->lo_water);
	CHECKMEM(obj);
	json_object_object_add(ctxobj, "lowater", obj);

	MCTXUNLOCK(ctx, &ctx->lock);
	json_object_array_add(array, ctxobj);
	return (ISC_R_SUCCESS);

 error:
	MCTXUNLOCK(ctx, &ctx->lock);
	if (ctxobj != NULL)
		json_object_put(ctxobj);
	return (result);
}

isc_result_t
isc_mem_renderjson(json_object *memobj) {
	isc_result_t result = ISC_R_SUCCESS;
	isc__mem_t *ctx;
	summarystat_t summary;
	uint64_t lost;
	json_object *ctxarray, *obj;

	memset(&summary, 0, sizeof(summary));
	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);

	ctxarray = json_object_new_array();
	CHECKMEM(ctxarray);

	LOCK(&contextslock);
	lost = totallost;
	for (ctx = ISC_LIST_HEAD(contexts);
	     ctx != NULL;
	     ctx = ISC_LIST_NEXT(ctx, link)) {
		result = json_renderctx(ctx, &summary, ctxarray);
		if (result != ISC_R_SUCCESS) {
			UNLOCK(&contextslock);
			goto error;
		}
	}
	UNLOCK(&contextslock);

	obj = json_object_new_int64(summary.total);
	CHECKMEM(obj);
	json_object_object_add(memobj, "TotalUse", obj);

	obj = json_object_new_int64(summary.inuse);
	CHECKMEM(obj);
	json_object_object_add(memobj, "InUse", obj);

	obj = json_object_new_int64(summary.blocksize);
	CHECKMEM(obj);
	json_object_object_add(memobj, "BlockSize", obj);

	obj = json_object_new_int64(summary.contextsize);
	CHECKMEM(obj);
	json_object_object_add(memobj, "ContextSize", obj);

	obj = json_object_new_int64(lost);
	CHECKMEM(obj);
	json_object_object_add(memobj, "Lost", obj);

	json_object_object_add(memobj, "contexts", ctxarray);
	return (ISC_R_SUCCESS);

 error:
	if (ctxarray != NULL)
		json_object_put(ctxarray);
	return (result);
}
#endif /* HAVE_JSON */

static isc_memcreatefunc_t mem_createfunc = NULL;

isc_result_t
isc_mem_register(isc_memcreatefunc_t createfunc) {
	isc_result_t result = ISC_R_SUCCESS;

	RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);

	LOCK(&createlock);
	if (mem_createfunc == NULL)
		mem_createfunc = createfunc;
	else
		result = ISC_R_EXISTS;
	UNLOCK(&createlock);

	return (result);
}


isc_result_t
isc__mem_create2(size_t init_max_size, size_t target_size, isc_mem_t **mctxp,
		 unsigned int flags)
{
	isc_result_t result;

	LOCK(&createlock);

	REQUIRE(mem_createfunc != NULL);
	result = (*mem_createfunc)(init_max_size, target_size, mctxp, flags);

	UNLOCK(&createlock);

	return (result);
}

isc_result_t
isc_mem_create(size_t init_max_size, size_t target_size, isc_mem_t **mctxp) {
	isc_result_t result;

	if (isc_bind9)
		return (isc_mem_createx2(init_max_size, target_size,
					 internal_memalloc, default_memfree,
					 NULL, mctxp, isc_mem_defaultflags));
	LOCK(&createlock);

	REQUIRE(mem_createfunc != NULL);
	result = (*mem_createfunc)(init_max_size, target_size, mctxp,
				   isc_mem_defaultflags);

	UNLOCK(&createlock);

	return (result);
}

isc_result_t
isc_mem_create2(size_t init_max_size, size_t target_size, isc_mem_t **mctxp,
		 unsigned int flags)
{
	if (isc_bind9)
		return (isc_mem_createx2(init_max_size, target_size,
					 internal_memalloc, default_memfree,
					 NULL, mctxp, flags));

	return (isc_mem_createx2(init_max_size, target_size,
				 default_memalloc, default_memfree,
				 NULL, mctxp, flags));
}

void
isc_mem_attach(isc_mem_t *source, isc_mem_t **targetp) {
	REQUIRE(ISCAPI_MCTX_VALID(source));
	REQUIRE(targetp != NULL && *targetp == NULL);

	if (isc_bind9)
		isc__mem_attach(source, targetp);
	else
		source->methods->attach(source, targetp);

	ENSURE(*targetp == source);
}

void
isc_mem_detach(isc_mem_t **mctxp) {
	REQUIRE(mctxp != NULL && ISCAPI_MCTX_VALID(*mctxp));

	if (isc_bind9)
		isc__mem_detach(mctxp);
	else
		(*mctxp)->methods->detach(mctxp);

	ENSURE(*mctxp == NULL);
}

void
isc_mem_destroy(isc_mem_t **mctxp) {
	REQUIRE(mctxp != NULL && ISCAPI_MCTX_VALID(*mctxp));

	if (isc_bind9)
		isc__mem_destroy(mctxp);
	else
		(*mctxp)->methods->destroy(mctxp);

	ENSURE(*mctxp == NULL);
}

void
isc_mem_setdestroycheck(isc_mem_t *mctx, bool flag) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	mctx->methods->setdestroycheck(mctx, flag);
}

void
isc_mem_setwater(isc_mem_t *ctx, isc_mem_water_t water, void *water_arg,
		 size_t hiwater, size_t lowater)
{
	REQUIRE(ISCAPI_MCTX_VALID(ctx));

	if (isc_bind9)
		isc__mem_setwater(ctx, water, water_arg, hiwater, lowater);
	else
		ctx->methods->setwater(ctx, water, water_arg, hiwater, lowater);
}

void
isc_mem_waterack(isc_mem_t *ctx, int flag) {
	REQUIRE(ISCAPI_MCTX_VALID(ctx));

	if (isc_bind9)
		isc__mem_waterack(ctx, flag);
	else
		ctx->methods->waterack(ctx, flag);
}

size_t
isc_mem_inuse(isc_mem_t *mctx) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		return (isc__mem_inuse(mctx));

	return (mctx->methods->inuse(mctx));
}

size_t
isc_mem_maxinuse(isc_mem_t *mctx) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		return (isc__mem_maxinuse(mctx));

	return (mctx->methods->maxinuse(mctx));
}

size_t
isc_mem_total(isc_mem_t *mctx) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		return (isc__mem_total(mctx));

	return (mctx->methods->total(mctx));
}

bool
isc_mem_isovermem(isc_mem_t *mctx) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		return (isc__mem_isovermem(mctx));

	return (mctx->methods->isovermem(mctx));
}


isc_result_t
isc_mempool_create(isc_mem_t *mctx, size_t size, isc_mempool_t **mpctxp) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	return (mctx->methods->mpcreate(mctx, size, mpctxp));
}

void
isc_mempool_destroy(isc_mempool_t **mpctxp) {
	REQUIRE(mpctxp != NULL && ISCAPI_MPOOL_VALID(*mpctxp));

	if (isc_bind9)
		isc__mempool_destroy(mpctxp);
	else
		(*mpctxp)->methods->destroy(mpctxp);

	ENSURE(*mpctxp == NULL);
}

unsigned int
isc_mempool_getallocated(isc_mempool_t *mpctx) {
	REQUIRE(ISCAPI_MPOOL_VALID(mpctx));

	if (isc_bind9)
		return (isc__mempool_getallocated(mpctx));

	return (mpctx->methods->getallocated(mpctx));
}

void
isc_mempool_setmaxalloc(isc_mempool_t *mpctx, unsigned int limit) {
	REQUIRE(ISCAPI_MPOOL_VALID(mpctx));

	if (isc_bind9)
		isc__mempool_setmaxalloc(mpctx, limit);
	else
		mpctx->methods->setmaxalloc(mpctx, limit);
}

void
isc_mempool_setfreemax(isc_mempool_t *mpctx, unsigned int limit) {
	REQUIRE(ISCAPI_MPOOL_VALID(mpctx));

	if (isc_bind9)
		isc__mempool_setfreemax(mpctx, limit);
	else
		mpctx->methods->setfreemax(mpctx, limit);
}

void
isc_mempool_setname(isc_mempool_t *mpctx, const char *name) {
	REQUIRE(ISCAPI_MPOOL_VALID(mpctx));

	if (isc_bind9)
		isc__mempool_setname(mpctx, name);
	else
		mpctx->methods->setname(mpctx, name);
}

void
isc_mempool_associatelock(isc_mempool_t *mpctx, isc_mutex_t *lock) {
	REQUIRE(ISCAPI_MPOOL_VALID(mpctx));

	if (isc_bind9)
		isc__mempool_associatelock(mpctx, lock);
	else
		mpctx->methods->associatelock(mpctx, lock);
}

void
isc_mempool_setfillcount(isc_mempool_t *mpctx, unsigned int limit) {
	REQUIRE(ISCAPI_MPOOL_VALID(mpctx));

	if (isc_bind9)
		isc__mempool_setfillcount(mpctx, limit);
	else
		mpctx->methods->setfillcount(mpctx, limit);
}

void *
isc__mem_get(isc_mem_t *mctx, size_t size FLARG) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		return (isc___mem_get(mctx, size FLARG_PASS));

	return (mctx->methods->memget(mctx, size FLARG_PASS));

}

void
isc__mem_put(isc_mem_t *mctx, void *ptr, size_t size FLARG) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		isc___mem_put(mctx, ptr, size FLARG_PASS);
	else
		mctx->methods->memput(mctx, ptr, size FLARG_PASS);
}

void
isc__mem_putanddetach(isc_mem_t **mctxp, void *ptr, size_t size FLARG) {
	REQUIRE(mctxp != NULL && ISCAPI_MCTX_VALID(*mctxp));

	if (isc_bind9)
		isc___mem_putanddetach(mctxp, ptr, size FLARG_PASS);
	else
		(*mctxp)->methods->memputanddetach(mctxp, ptr, size FLARG_PASS);

	/*
	 * XXX: We cannot always ensure *mctxp == NULL here
	 * (see lib/isc/mem.c).
	 */
}

void *
isc__mem_allocate(isc_mem_t *mctx, size_t size FLARG) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		return (isc___mem_allocate(mctx, size FLARG_PASS));

	return (mctx->methods->memallocate(mctx, size FLARG_PASS));
}

void *
isc__mem_reallocate(isc_mem_t *mctx, void *ptr, size_t size FLARG) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		return (isc___mem_reallocate(mctx, ptr, size FLARG_PASS));

	return (mctx->methods->memreallocate(mctx, ptr, size FLARG_PASS));
}

char *
isc__mem_strdup(isc_mem_t *mctx, const char *s FLARG) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		return (isc___mem_strdup(mctx, s FLARG_PASS));

	return (mctx->methods->memstrdup(mctx, s FLARG_PASS));
}

void
isc__mem_free(isc_mem_t *mctx, void *ptr FLARG) {
	REQUIRE(ISCAPI_MCTX_VALID(mctx));

	if (isc_bind9)
		isc___mem_free(mctx, ptr FLARG_PASS);
	else
		mctx->methods->memfree(mctx, ptr FLARG_PASS);
}

void *
isc__mempool_get(isc_mempool_t *mpctx FLARG) {
	REQUIRE(ISCAPI_MPOOL_VALID(mpctx));

	if (isc_bind9)
		return (isc___mempool_get(mpctx FLARG_PASS));

	return (mpctx->methods->get(mpctx FLARG_PASS));
}

void
isc__mempool_put(isc_mempool_t *mpctx, void *mem FLARG) {
	REQUIRE(ISCAPI_MPOOL_VALID(mpctx));

	if (isc_bind9)
		isc___mempool_put(mpctx, mem FLARG_PASS);
	else
		mpctx->methods->put(mpctx, mem FLARG_PASS);
}
