Adding upstream version 2.4.57+dfsg.upstream/2.4.57+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 972 insertions, 0 deletions

diff --git a/servers/slapd/zn_malloc.c b/servers/slapd/zn_malloc.c
new file mode 100644
index 0000000..4bdecfc
--- /dev/null
+++ b/servers/slapd/zn_malloc.c
@@ -0,0 +1,972 @@
+/* zn_malloc.c - zone-based malloc routines */
+/* $OpenLDAP$*/
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2003-2021 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+/* Portions Copyright 2004 IBM Corporation
+ * All rights reserved.
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ */
+/* ACKNOWLEDGEMENTS
+ * This work originally developed by Jong-Hyuk Choi for inclusion in
+ * OpenLDAP Software.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+#include <ac/string.h>
+#include <sys/types.h>
+#include <fcntl.h>
+
+#include "slap.h"
+
+#ifdef SLAP_ZONE_ALLOC
+
+#include <sys/mman.h>
+
+static int slap_zone_cmp(const void *v1, const void *v2);
+void * slap_replenish_zopool(void *ctx);
+
+static void
+slap_zo_release(void *data)
+{
+	struct zone_object *zo = (struct zone_object *)data;
+	ch_free( zo );
+}
+
+void
+slap_zn_mem_destroy(
+	void *ctx
+)
+{
+	struct zone_heap *zh = ctx;
+	int pad = 2*sizeof(int)-1, pad_shift;
+	int order_start = -1, i, j;
+	struct zone_object *zo;
+
+	pad_shift = pad - 1;
+	do {
+		order_start++;
+	} while (pad_shift >>= 1);
+
+	ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+	for (i = 0; i < zh->zh_zoneorder - order_start + 1; i++) {
+		zo = LDAP_LIST_FIRST(&zh->zh_free[i]);
+		while (zo) {
+			struct zone_object *zo_tmp = zo;
+			zo = LDAP_LIST_NEXT(zo, zo_link);
+			LDAP_LIST_REMOVE(zo_tmp, zo_link);
+			LDAP_LIST_INSERT_HEAD(&zh->zh_zopool, zo_tmp, zo_link);
+		}
+	}
+	ch_free(zh->zh_free);
+
+	for (i = 0; i < zh->zh_numzones; i++) {
+		for (j = 0; j < zh->zh_zoneorder - order_start + 1; j++) {
+			ch_free(zh->zh_maps[i][j]);
+		}
+		ch_free(zh->zh_maps[i]);
+		munmap(zh->zh_zones[i], zh->zh_zonesize);
+		ldap_pvt_thread_rdwr_destroy(&zh->zh_znlock[i]);
+	}
+	ch_free(zh->zh_maps);
+	ch_free(zh->zh_zones);
+	ch_free(zh->zh_seqno);
+	ch_free(zh->zh_znlock);
+
+	avl_free(zh->zh_zonetree, slap_zo_release);
+
+	zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+	while (zo) {
+		struct zone_object *zo_tmp = zo;
+		zo = LDAP_LIST_NEXT(zo, zo_link);
+		if (!zo_tmp->zo_blockhead) {
+			LDAP_LIST_REMOVE(zo_tmp, zo_link);
+		}
+	}
+	zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+	while (zo) {
+		struct zone_object *zo_tmp = zo;
+		zo = LDAP_LIST_NEXT(zo, zo_link);
+		ch_free(zo_tmp);
+	}
+	ldap_pvt_thread_mutex_unlock(&zh->zh_mutex);
+	ldap_pvt_thread_rdwr_destroy(&zh->zh_lock);
+	ldap_pvt_thread_mutex_destroy(&zh->zh_mutex);
+	ch_free(zh);
+}
+
+void *
+slap_zn_mem_create(
+	ber_len_t initsize,
+	ber_len_t maxsize,
+	ber_len_t deltasize,
+	ber_len_t zonesize
+)
+{
+	struct zone_heap *zh = NULL;
+	ber_len_t zpad;
+	int pad = 2*sizeof(int)-1, pad_shift;
+	int size_shift;
+	int order = -1, order_start = -1, order_end = -1;
+	int i, j;
+	struct zone_object *zo;
+
+	Debug(LDAP_DEBUG_NONE,
+		"--> slap_zn_mem_create: initsize=%d, maxsize=%d\n",
+		initsize, maxsize, 0);
+	Debug(LDAP_DEBUG_NONE,
+		"++> slap_zn_mem_create: deltasize=%d, zonesize=%d\n",
+		deltasize, zonesize, 0);
+
+	zh = (struct zone_heap *)ch_calloc(1, sizeof(struct zone_heap));
+
+	zh->zh_fd = open("/dev/zero", O_RDWR);
+
+	if ( zonesize ) {
+		zh->zh_zonesize = zonesize;
+	} else {
+		zh->zh_zonesize = SLAP_ZONE_SIZE;
+	}
+
+	zpad = zh->zh_zonesize - 1;
+	zh->zh_numzones = ((initsize + zpad) & ~zpad) / zh->zh_zonesize;
+
+	if ( maxsize && maxsize >= initsize ) {
+		zh->zh_maxzones = ((maxsize + zpad) & ~zpad) / zh->zh_zonesize;
+	} else {
+		zh->zh_maxzones = ((initsize + zpad) & ~zpad) / zh->zh_zonesize;
+	}
+
+	if ( deltasize ) {
+		zh->zh_deltazones = ((deltasize + zpad) & ~zpad) / zh->zh_zonesize;
+	} else {
+		zh->zh_deltazones = ((SLAP_ZONE_DELTA+zpad) & ~zpad) / zh->zh_zonesize;
+	}
+
+	size_shift = zh->zh_zonesize - 1;
+	do {
+		order_end++;
+	} while (size_shift >>= 1);
+
+	pad_shift = pad - 1;
+	do {
+		order_start++;
+	} while (pad_shift >>= 1);
+
+	order = order_end - order_start + 1;
+
+	zh->zh_zones = (void **)ch_malloc(zh->zh_maxzones * sizeof(void*));
+	zh->zh_znlock = (ldap_pvt_thread_rdwr_t *)ch_malloc(
+						zh->zh_maxzones * sizeof(ldap_pvt_thread_rdwr_t *));
+	zh->zh_maps = (unsigned char ***)ch_malloc(
+					zh->zh_maxzones * sizeof(unsigned char**));
+
+	zh->zh_zoneorder = order_end;
+	zh->zh_free = (struct zh_freelist *)
+					ch_malloc(order * sizeof(struct zh_freelist));
+	zh->zh_seqno = (unsigned long *)ch_calloc(zh->zh_maxzones,
+											sizeof(unsigned long));
+	for (i = 0; i < order; i++) {
+		LDAP_LIST_INIT(&zh->zh_free[i]);
+	}
+	LDAP_LIST_INIT(&zh->zh_zopool);
+
+	for (i = 0; i < zh->zh_numzones; i++) {
+		zh->zh_zones[i] = mmap(0, zh->zh_zonesize, PROT_READ | PROT_WRITE,
+							MAP_PRIVATE, zh->zh_fd, 0);
+		zh->zh_maps[i] = (unsigned char **)
+					ch_malloc(order * sizeof(unsigned char *));
+		for (j = 0; j < order; j++) {
+			int shiftamt = order_start + 1 + j;
+			int nummaps = zh->zh_zonesize >> shiftamt;
+			assert(nummaps);
+			nummaps >>= 3;
+			if (!nummaps) nummaps = 1;
+			zh->zh_maps[i][j] = (unsigned char *)ch_malloc(nummaps);
+			memset(zh->zh_maps[i][j], 0, nummaps);
+		}
+
+		if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+			slap_replenish_zopool(zh);
+		}
+		zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+		LDAP_LIST_REMOVE(zo, zo_link);
+		zo->zo_ptr = zh->zh_zones[i];
+		zo->zo_idx = i;
+		LDAP_LIST_INSERT_HEAD(&zh->zh_free[order-1], zo, zo_link);
+
+		if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+			slap_replenish_zopool(zh);
+		}
+		zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+		LDAP_LIST_REMOVE(zo, zo_link);
+		zo->zo_ptr = zh->zh_zones[i];
+		zo->zo_siz = zh->zh_zonesize;
+		zo->zo_idx = i;
+		avl_insert(&zh->zh_zonetree, zo, slap_zone_cmp, avl_dup_error);
+		ldap_pvt_thread_rdwr_init(&zh->zh_znlock[i]);
+	}
+
+	LDAP_STAILQ_INIT(&zh->zh_latency_history_queue);
+	ldap_pvt_thread_mutex_init(&zh->zh_mutex);
+	ldap_pvt_thread_rdwr_init(&zh->zh_lock);
+
+	return zh;
+}
+
+void *
+slap_zn_malloc(
+    ber_len_t	size,
+	void *ctx
+)
+{
+	struct zone_heap *zh = ctx;
+	ber_len_t size_shift;
+	int pad = 2*sizeof(int)-1, pad_shift;
+	int order = -1, order_start = -1;
+	struct zone_object *zo, *zo_new, *zo_left, *zo_right;
+	ber_len_t *ptr, *new;
+	int idx;
+	unsigned long diff;
+	int i, j, k;
+
+	Debug(LDAP_DEBUG_NONE,
+		"--> slap_zn_malloc: size=%d\n", size, 0, 0);
+
+	if (!zh) return ber_memalloc_x(size, NULL);
+
+	/* round up to doubleword boundary */
+	size += 2*sizeof(ber_len_t) + pad;
+	size &= ~pad;
+
+	size_shift = size - 1;
+	do {
+		order++;
+	} while (size_shift >>= 1);
+
+	pad_shift = pad - 1;
+	do {
+		order_start++;
+	} while (pad_shift >>= 1);
+
+retry:
+
+	ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+	for (i = order; i <= zh->zh_zoneorder &&
+			LDAP_LIST_EMPTY(&zh->zh_free[i-order_start]); i++);
+
+	if (i == order) {
+		zo_new = LDAP_LIST_FIRST(&zh->zh_free[i-order_start]);
+		LDAP_LIST_REMOVE(zo_new, zo_link);
+		ptr = zo_new->zo_ptr;
+		idx = zo_new->zo_idx;
+		diff = (unsigned long)((char*)ptr -
+				(char*)zh->zh_zones[idx]) >> (order + 1);
+		zh->zh_maps[idx][order-order_start][diff>>3] |= (1 << (diff & 0x7));
+		*ptr++ = zh->zh_seqno[idx];
+		*ptr++ = size - 2*sizeof(ber_len_t);
+		zo_new->zo_ptr = NULL;
+		zo_new->zo_idx = -1;
+		LDAP_LIST_INSERT_HEAD(&zh->zh_zopool, zo_new, zo_link);
+		ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+		Debug(LDAP_DEBUG_NONE, "slap_zn_malloc: returning 0x%x, 0x%x\n",
+				ptr, (int)ptr>>(zh->zh_zoneorder+1), 0);
+		return((void*)ptr);
+	} else if (i <= zh->zh_zoneorder) {
+		for (j = i; j > order; j--) {
+			zo_left = LDAP_LIST_FIRST(&zh->zh_free[j-order_start]);
+			LDAP_LIST_REMOVE(zo_left, zo_link);
+			if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+				slap_replenish_zopool(zh);
+			}
+			zo_right = LDAP_LIST_FIRST(&zh->zh_zopool);
+			LDAP_LIST_REMOVE(zo_right, zo_link);
+			zo_right->zo_ptr = zo_left->zo_ptr + (1 << j);
+			zo_right->zo_idx = zo_left->zo_idx;
+			Debug(LDAP_DEBUG_NONE,
+				"slap_zn_malloc: split (left=0x%x, right=0x%x)\n",
+				zo_left->zo_ptr, zo_right->zo_ptr, 0);
+			if (j == order + 1) {
+				ptr = zo_left->zo_ptr;
+				diff = (unsigned long)((char*)ptr -
+						(char*)zh->zh_zones[zo_left->zo_idx]) >> (order+1);
+				zh->zh_maps[zo_left->zo_idx][order-order_start][diff>>3] |=
+						(1 << (diff & 0x7));
+				*ptr++ = zh->zh_seqno[zo_left->zo_idx];
+				*ptr++ = size - 2*sizeof(ber_len_t);
+				LDAP_LIST_INSERT_HEAD(
+						&zh->zh_free[j-1-order_start], zo_right, zo_link);
+				LDAP_LIST_INSERT_HEAD(&zh->zh_zopool, zo_left, zo_link);
+				ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+				Debug(LDAP_DEBUG_NONE,
+					"slap_zn_malloc: returning 0x%x, 0x%x\n",
+					ptr, (int)ptr>>(zh->zh_zoneorder+1), 0);
+				return((void*)ptr);
+			} else {
+				LDAP_LIST_INSERT_HEAD(
+						&zh->zh_free[j-1-order_start], zo_right, zo_link);
+				LDAP_LIST_INSERT_HEAD(
+						&zh->zh_free[j-1-order_start], zo_left, zo_link);
+			}
+		}
+		assert(0);
+	} else {
+
+		if ( zh->zh_maxzones < zh->zh_numzones + zh->zh_deltazones ) {
+			ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+			Debug( LDAP_DEBUG_TRACE,
+				"zn_malloc %lu: ch_malloc\n",
+				(long)size, 0, 0);
+			Debug(LDAP_DEBUG_NONE,
+				"slap_zn_malloc: returning 0x%x, 0x%x\n",
+				ptr, (int)ptr>>(zh->zh_zoneorder+1), 0);
+			return (void*)ch_malloc(size);
+		}
+
+		for (i = zh->zh_numzones; i < zh->zh_numzones+zh->zh_deltazones; i++) {
+			zh->zh_zones[i] = mmap(0, zh->zh_zonesize, PROT_READ | PROT_WRITE,
+								MAP_PRIVATE, zh->zh_fd, 0);
+			zh->zh_maps[i] = (unsigned char **)
+						ch_malloc((zh->zh_zoneorder - order_start + 1) *
+						sizeof(unsigned char *));
+			for (j = 0; j < zh->zh_zoneorder-order_start+1; j++) {
+				int shiftamt = order_start + 1 + j;
+				int nummaps = zh->zh_zonesize >> shiftamt;
+				assert(nummaps);
+				nummaps >>= 3;
+				if (!nummaps) nummaps = 1;
+				zh->zh_maps[i][j] = (unsigned char *)ch_malloc(nummaps);
+				memset(zh->zh_maps[i][j], 0, nummaps);
+			}
+	
+			if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+				slap_replenish_zopool(zh);
+			}
+			zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+			LDAP_LIST_REMOVE(zo, zo_link);
+			zo->zo_ptr = zh->zh_zones[i];
+			zo->zo_idx = i;
+			LDAP_LIST_INSERT_HEAD(&zh->
+						zh_free[zh->zh_zoneorder-order_start],zo,zo_link);
+	
+			if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+				slap_replenish_zopool(zh);
+			}
+			zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+			LDAP_LIST_REMOVE(zo, zo_link);
+			zo->zo_ptr = zh->zh_zones[i];
+			zo->zo_siz = zh->zh_zonesize;
+			zo->zo_idx = i;
+			avl_insert(&zh->zh_zonetree, zo, slap_zone_cmp, avl_dup_error);
+			ldap_pvt_thread_rdwr_init(&zh->zh_znlock[i]);
+		}
+		zh->zh_numzones += zh->zh_deltazones;
+		ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+		goto retry;
+	}
+}
+
+void *
+slap_zn_calloc( ber_len_t n, ber_len_t size, void *ctx )
+{
+	void *new;
+
+	new = slap_zn_malloc( n*size, ctx );
+	if ( new ) {
+		memset( new, 0, n*size );
+	}
+	return new;
+}
+
+void *
+slap_zn_realloc(void *ptr, ber_len_t size, void *ctx)
+{
+	struct zone_heap *zh = ctx;
+	int pad = 2*sizeof(int)-1, pad_shift;
+	int order_start = -1, order = -1;
+	struct zone_object zoi, *zoo;
+	ber_len_t *p = (ber_len_t *)ptr, *new;
+	unsigned long diff;
+	int i;
+	void *newptr = NULL;
+	struct zone_heap *zone = NULL;
+
+	Debug(LDAP_DEBUG_NONE,
+		"--> slap_zn_realloc: ptr=0x%x, size=%d\n", ptr, size, 0);
+
+	if (ptr == NULL)
+		return slap_zn_malloc(size, zh);
+
+	zoi.zo_ptr = p;
+	zoi.zo_idx = -1;
+
+	if (zh) {
+		ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+		zoo = avl_find(zh->zh_zonetree, &zoi, slap_zone_cmp);
+		ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+	}
+
+	/* Not our memory? */
+	if (!zoo) {
+		/* duplicate of realloc behavior, oh well */
+		new = ber_memrealloc_x(ptr, size, NULL);
+		if (new) {
+			return new;
+		}
+		Debug(LDAP_DEBUG_ANY, "ch_realloc of %lu bytes failed\n",
+				(long) size, 0, 0);
+		assert(0);
+		exit( EXIT_FAILURE );
+	}
+
+	assert(zoo->zo_idx != -1);	
+
+	zone = zh->zh_zones[zoo->zo_idx];
+
+	if (size == 0) {
+		slap_zn_free(ptr, zh);
+		return NULL;
+	}
+
+	newptr = slap_zn_malloc(size, zh);
+	if (size < p[-1]) {
+		AC_MEMCPY(newptr, ptr, size);
+	} else {
+		AC_MEMCPY(newptr, ptr, p[-1]);
+	}
+	slap_zn_free(ptr, zh);
+	return newptr;
+}
+
+void
+slap_zn_free(void *ptr, void *ctx)
+{
+	struct zone_heap *zh = ctx;
+	int size, size_shift, order_size;
+	int pad = 2*sizeof(int)-1, pad_shift;
+	ber_len_t *p = (ber_len_t *)ptr, *tmpp;
+	int order_start = -1, order = -1;
+	struct zone_object zoi, *zoo, *zo;
+	unsigned long diff;
+	int i, k, inserted = 0, idx;
+	struct zone_heap *zone = NULL;
+
+	zoi.zo_ptr = p;
+	zoi.zo_idx = -1;
+
+	Debug(LDAP_DEBUG_NONE, "--> slap_zn_free: ptr=0x%x\n", ptr, 0, 0);
+
+	if (zh) {
+		ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+		zoo = avl_find(zh->zh_zonetree, &zoi, slap_zone_cmp);
+		ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+	}
+
+	if (!zoo) {
+		ber_memfree_x(ptr, NULL);
+	} else {
+		idx = zoo->zo_idx;
+		assert(idx != -1);
+		zone = zh->zh_zones[idx];
+
+		size = *(--p);
+		size_shift = size + 2*sizeof(ber_len_t) - 1;
+		do {
+			order++;
+		} while (size_shift >>= 1);
+
+		pad_shift = pad - 1;
+		do {
+			order_start++;
+		} while (pad_shift >>= 1);
+
+		ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+		for (i = order, tmpp = p; i <= zh->zh_zoneorder; i++) {
+			order_size = 1 << (i+1);
+			diff = (unsigned long)((char*)tmpp - (char*)zone) >> (i+1);
+			zh->zh_maps[idx][i-order_start][diff>>3] &= (~(1 << (diff & 0x7)));
+			if (diff == ((diff>>1)<<1)) {
+				if (!(zh->zh_maps[idx][i-order_start][(diff+1)>>3] &
+						(1<<((diff+1)&0x7)))) {
+					zo = LDAP_LIST_FIRST(&zh->zh_free[i-order_start]);
+					while (zo) {
+						if ((char*)zo->zo_ptr == (char*)tmpp) {
+							LDAP_LIST_REMOVE( zo, zo_link );
+						} else if ((char*)zo->zo_ptr ==
+								(char*)tmpp + order_size) {
+							LDAP_LIST_REMOVE(zo, zo_link);
+							break;
+						}
+						zo = LDAP_LIST_NEXT(zo, zo_link);
+					}
+					if (zo) {
+						if (i < zh->zh_zoneorder) {
+							inserted = 1;
+							zo->zo_ptr = tmpp;
+							Debug(LDAP_DEBUG_NONE,
+								"slap_zn_free: merging 0x%x\n",
+								zo->zo_ptr, 0, 0);
+							LDAP_LIST_INSERT_HEAD(&zh->zh_free[i-order_start+1],
+									zo, zo_link);
+						}
+						continue;
+					} else {
+						if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+							slap_replenish_zopool(zh);
+						}
+						zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+						LDAP_LIST_REMOVE(zo, zo_link);
+						zo->zo_ptr = tmpp;
+						zo->zo_idx = idx;
+						Debug(LDAP_DEBUG_NONE,
+							"slap_zn_free: merging 0x%x\n",
+							zo->zo_ptr, 0, 0);
+						LDAP_LIST_INSERT_HEAD(&zh->zh_free[i-order_start],
+								zo, zo_link);
+						break;
+
+						Debug(LDAP_DEBUG_ANY, "slap_zn_free: "
+							"free object not found while bit is clear.\n",
+							0, 0, 0);
+						assert(zo != NULL);
+
+					}
+				} else {
+					if (!inserted) {
+						if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+							slap_replenish_zopool(zh);
+						}
+						zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+						LDAP_LIST_REMOVE(zo, zo_link);
+						zo->zo_ptr = tmpp;
+						zo->zo_idx = idx;
+						Debug(LDAP_DEBUG_NONE,
+							"slap_zn_free: merging 0x%x\n",
+							zo->zo_ptr, 0, 0);
+						LDAP_LIST_INSERT_HEAD(&zh->zh_free[i-order_start],
+								zo, zo_link);
+					}
+					break;
+				}
+			} else {
+				if (!(zh->zh_maps[idx][i-order_start][(diff-1)>>3] &
+						(1<<((diff-1)&0x7)))) {
+					zo = LDAP_LIST_FIRST(&zh->zh_free[i-order_start]);
+					while (zo) {
+						if ((char*)zo->zo_ptr == (char*)tmpp) {
+							LDAP_LIST_REMOVE(zo, zo_link);
+						} else if ((char*)tmpp == zo->zo_ptr + order_size) {
+							LDAP_LIST_REMOVE(zo, zo_link);
+							tmpp = zo->zo_ptr;
+							break;
+						}
+						zo = LDAP_LIST_NEXT(zo, zo_link);
+					}
+					if (zo) {
+						if (i < zh->zh_zoneorder) {
+							inserted = 1;
+							Debug(LDAP_DEBUG_NONE,
+								"slap_zn_free: merging 0x%x\n",
+								zo->zo_ptr, 0, 0);
+							LDAP_LIST_INSERT_HEAD(&zh->zh_free[i-order_start+1],
+									zo, zo_link);
+							continue;
+						}
+					} else {
+						if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+							slap_replenish_zopool(zh);
+						}
+						zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+						LDAP_LIST_REMOVE(zo, zo_link);
+						zo->zo_ptr = tmpp;
+						zo->zo_idx = idx;
+						Debug(LDAP_DEBUG_NONE,
+							"slap_zn_free: merging 0x%x\n",
+							zo->zo_ptr, 0, 0);
+						LDAP_LIST_INSERT_HEAD(&zh->zh_free[i-order_start],
+								zo, zo_link);
+						break;
+
+						Debug(LDAP_DEBUG_ANY, "slap_zn_free: "
+							"free object not found while bit is clear.\n",
+							0, 0, 0 );
+						assert(zo != NULL);
+
+					}
+				} else {
+					if ( !inserted ) {
+						if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+							slap_replenish_zopool(zh);
+						}
+						zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+						LDAP_LIST_REMOVE(zo, zo_link);
+						zo->zo_ptr = tmpp;
+						zo->zo_idx = idx;
+						Debug(LDAP_DEBUG_NONE,
+							"slap_zn_free: merging 0x%x\n",
+							zo->zo_ptr, 0, 0);
+						LDAP_LIST_INSERT_HEAD(&zh->zh_free[i-order_start],
+								zo, zo_link);
+					}
+					break;
+				}
+			}
+		}
+		ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+	}
+}
+
+static int
+slap_zone_cmp(const void *v1, const void *v2)
+{
+	const struct zone_object *zo1 = v1;
+	const struct zone_object *zo2 = v2;
+	char *ptr1;
+	char *ptr2;
+	ber_len_t zpad;
+
+	zpad = zo2->zo_siz - 1;
+	ptr1 = (char*)(((unsigned long)zo1->zo_ptr + zpad) & ~zpad);
+	ptr2 = (char*)zo2->zo_ptr + ((char*)ptr1 - (char*)zo1->zo_ptr);
+	ptr2 = (char*)(((unsigned long)ptr2 + zpad) & ~zpad);
+	return (int)((char*)ptr1 - (char*)ptr2);
+}
+
+void *
+slap_replenish_zopool(
+	void *ctx
+)
+{
+	struct zone_heap* zh = ctx;
+	struct zone_object *zo_block;
+	int i;
+
+	zo_block = (struct zone_object *)ch_malloc(
+					SLAP_ZONE_ZOBLOCK * sizeof(struct zone_object));
+
+	if ( zo_block == NULL ) {
+		return NULL;
+	}
+
+	zo_block[0].zo_blockhead = 1;
+	LDAP_LIST_INSERT_HEAD(&zh->zh_zopool, &zo_block[0], zo_link);
+	for (i = 1; i < SLAP_ZONE_ZOBLOCK; i++) {
+		zo_block[i].zo_blockhead = 0;
+		LDAP_LIST_INSERT_HEAD(&zh->zh_zopool, &zo_block[i], zo_link );
+	}
+
+	return zo_block;
+}
+
+int
+slap_zn_invalidate(
+	void *ctx,
+	void *ptr
+)
+{
+	struct zone_heap* zh = ctx;
+	struct zone_object zoi, *zoo;
+	struct zone_heap *zone = NULL;
+	int seqno = *((ber_len_t*)ptr - 2);
+	int idx = -1, rc = 0;
+	int pad = 2*sizeof(int)-1, pad_shift;
+	int order_start = -1, i;
+	struct zone_object *zo;
+
+	pad_shift = pad - 1;
+	do {
+		order_start++;
+	} while (pad_shift >>= 1);
+
+	zoi.zo_ptr = ptr;
+	zoi.zo_idx = -1;
+
+	ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+	zoo = avl_find(zh->zh_zonetree, &zoi, slap_zone_cmp);
+
+	if (zoo) {
+		idx = zoo->zo_idx;
+		assert(idx != -1);
+		madvise(zh->zh_zones[idx], zh->zh_zonesize, MADV_DONTNEED);
+		for (i = 0; i < zh->zh_zoneorder - order_start + 1; i++) {
+			int shiftamt = order_start + 1 + i;
+			int nummaps = zh->zh_zonesize >> shiftamt;
+			assert(nummaps);
+			nummaps >>= 3;
+			if (!nummaps) nummaps = 1;
+			memset(zh->zh_maps[idx][i], 0, nummaps);
+			zo = LDAP_LIST_FIRST(&zh->zh_free[i]);
+			while (zo) {
+				struct zone_object *zo_tmp = zo;
+				zo = LDAP_LIST_NEXT(zo, zo_link);
+				if (zo_tmp && zo_tmp->zo_idx == idx) {
+					LDAP_LIST_REMOVE(zo_tmp, zo_link);
+					LDAP_LIST_INSERT_HEAD(&zh->zh_zopool, zo_tmp, zo_link);
+				}
+			}
+		}
+		if (LDAP_LIST_EMPTY(&zh->zh_zopool)) {
+			slap_replenish_zopool(zh);
+		}
+		zo = LDAP_LIST_FIRST(&zh->zh_zopool);
+		LDAP_LIST_REMOVE(zo, zo_link);
+		zo->zo_ptr = zh->zh_zones[idx];
+		zo->zo_idx = idx;
+		LDAP_LIST_INSERT_HEAD(&zh->zh_free[zh->zh_zoneorder-order_start],
+								zo, zo_link);
+		zh->zh_seqno[idx]++;
+	} else {
+		Debug(LDAP_DEBUG_NONE, "zone not found for (ctx=0x%x, ptr=0x%x) !\n",
+				ctx, ptr, 0);
+	}
+
+	ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+	Debug(LDAP_DEBUG_NONE, "zone %d invalidate\n", idx, 0, 0);
+	return rc;
+}
+
+int
+slap_zn_validate(
+	void *ctx,
+	void *ptr,
+	int seqno
+)
+{
+	struct zone_heap* zh = ctx;
+	struct zone_object zoi, *zoo;
+	struct zone_heap *zone = NULL;
+	int idx, rc = 0;
+
+	zoi.zo_ptr = ptr;
+	zoi.zo_idx = -1;
+
+	zoo = avl_find(zh->zh_zonetree, &zoi, slap_zone_cmp);
+
+	if (zoo) {
+		idx = zoo->zo_idx;
+		assert(idx != -1);
+		assert(seqno <= zh->zh_seqno[idx]);
+		rc = (seqno == zh->zh_seqno[idx]);
+	}
+
+	return rc;
+}
+
+int slap_zh_rlock(
+	void *ctx
+)
+{
+	struct zone_heap* zh = ctx;
+	ldap_pvt_thread_rdwr_rlock(&zh->zh_lock);
+}
+
+int slap_zh_runlock(
+	void *ctx
+)
+{
+	struct zone_heap* zh = ctx;
+	ldap_pvt_thread_rdwr_runlock(&zh->zh_lock);
+}
+
+int slap_zh_wlock(
+	void *ctx
+)
+{
+	struct zone_heap* zh = ctx;
+	ldap_pvt_thread_rdwr_wlock(&zh->zh_lock);
+}
+
+int slap_zh_wunlock(
+	void *ctx
+)
+{
+	struct zone_heap* zh = ctx;
+	ldap_pvt_thread_rdwr_wunlock(&zh->zh_lock);
+}
+
+int slap_zn_rlock(
+	void *ctx,
+	void *ptr
+)
+{
+	struct zone_heap* zh = ctx;
+	struct zone_object zoi, *zoo;
+	struct zone_heap *zone = NULL;
+	int idx;
+
+	zoi.zo_ptr = ptr;
+	zoi.zo_idx = -1;
+
+	ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+	zoo = avl_find(zh->zh_zonetree, &zoi, slap_zone_cmp);
+	ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+
+	if (zoo) {
+		idx = zoo->zo_idx;
+		assert(idx != -1);
+		ldap_pvt_thread_rdwr_rlock(&zh->zh_znlock[idx]);
+	}
+}
+
+int slap_zn_runlock(
+	void *ctx,
+	void *ptr
+)
+{
+	struct zone_heap* zh = ctx;
+	struct zone_object zoi, *zoo;
+	struct zone_heap *zone = NULL;
+	int idx;
+
+	zoi.zo_ptr = ptr;
+	zoi.zo_idx = -1;
+
+	ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+	zoo = avl_find(zh->zh_zonetree, &zoi, slap_zone_cmp);
+	ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+
+	if (zoo) {
+		idx = zoo->zo_idx;
+		assert(idx != -1);
+		ldap_pvt_thread_rdwr_runlock(&zh->zh_znlock[idx]);
+	}
+}
+
+int slap_zn_wlock(
+	void *ctx,
+	void *ptr
+)
+{
+	struct zone_heap* zh = ctx;
+	struct zone_object zoi, *zoo;
+	struct zone_heap *zone = NULL;
+	int idx;
+
+	zoi.zo_ptr = ptr;
+	zoi.zo_idx = -1;
+
+	ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+	zoo = avl_find(zh->zh_zonetree, &zoi, slap_zone_cmp);
+	ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+
+	if (zoo) {
+		idx = zoo->zo_idx;
+		assert(idx != -1);
+		ldap_pvt_thread_rdwr_wlock(&zh->zh_znlock[idx]);
+	}
+}
+
+int slap_zn_wunlock(
+	void *ctx,
+	void *ptr
+)
+{
+	struct zone_heap* zh = ctx;
+	struct zone_object zoi, *zoo;
+	struct zone_heap *zone = NULL;
+	int idx;
+
+	zoi.zo_ptr = ptr;
+	zoi.zo_idx = -1;
+
+	ldap_pvt_thread_mutex_lock( &zh->zh_mutex );
+	zoo = avl_find(zh->zh_zonetree, &zoi, slap_zone_cmp);
+	ldap_pvt_thread_mutex_unlock( &zh->zh_mutex );
+
+	if (zoo) {
+		idx = zoo->zo_idx;
+		assert(idx != -1);
+		ldap_pvt_thread_rdwr_wunlock(&zh->zh_znlock[idx]);
+	}
+}
+
+#define T_SEC_IN_USEC 1000000
+
+static int
+slap_timediff(struct timeval *tv_begin, struct timeval *tv_end)
+{
+	uint64_t t_begin, t_end, t_diff;
+
+	t_begin = T_SEC_IN_USEC * tv_begin->tv_sec + tv_begin->tv_usec;
+	t_end  = T_SEC_IN_USEC * tv_end->tv_sec  + tv_end->tv_usec;
+	t_diff  = t_end - t_begin;
+	
+	if ( t_diff < 0 )
+		t_diff = 0;
+
+	return (int)t_diff;
+}
+
+void
+slap_set_timing(struct timeval *tv_set)
+{
+	gettimeofday(tv_set, (struct timezone *)NULL);
+}
+
+int
+slap_measure_timing(struct timeval *tv_set, struct timeval *tv_measure)
+{
+	gettimeofday(tv_measure, (struct timezone *)NULL);
+	return(slap_timediff(tv_set, tv_measure));
+}
+
+#define EMA_WEIGHT 0.999000
+#define SLAP_ZN_LATENCY_HISTORY_QLEN 500
+int
+slap_zn_latency_history(void* ctx, int ea_latency)
+{
+/* TODO: monitor /proc/stat (swap) as well */
+	struct zone_heap* zh = ctx;
+	double t_diff = 0.0;
+
+	zh->zh_ema_latency = (double)ea_latency * (1.0 - EMA_WEIGHT)
+					+ zh->zh_ema_latency * EMA_WEIGHT;
+	if (!zh->zh_swapping && zh->zh_ema_samples++ % 100 == 99) {
+		struct zone_latency_history *zlh_entry;
+		zlh_entry = ch_calloc(1, sizeof(struct zone_latency_history));
+		zlh_entry->zlh_latency = zh->zh_ema_latency;
+		LDAP_STAILQ_INSERT_TAIL(
+				&zh->zh_latency_history_queue, zlh_entry, zlh_next);
+		zh->zh_latency_history_qlen++;
+		while (zh->zh_latency_history_qlen > SLAP_ZN_LATENCY_HISTORY_QLEN) {
+			struct zone_latency_history *zlh;
+			zlh = LDAP_STAILQ_FIRST(&zh->zh_latency_history_queue);
+			LDAP_STAILQ_REMOVE_HEAD(
+					&zh->zh_latency_history_queue, zlh_next);
+			zh->zh_latency_history_qlen--;
+			ch_free(zlh);
+		}
+		if (zh->zh_latency_history_qlen == SLAP_ZN_LATENCY_HISTORY_QLEN) {
+			struct zone_latency_history *zlh_first, *zlh_last;
+			zlh_first = LDAP_STAILQ_FIRST(&zh->zh_latency_history_queue);
+			zlh_last = LDAP_STAILQ_LAST(&zh->zh_latency_history_queue,
+						zone_latency_history, zlh_next);
+			t_diff = zlh_last->zlh_latency - zlh_first->zlh_latency;
+		}
+		if (t_diff >= 2000) {
+			zh->zh_latency_jump++;
+		} else {
+			zh->zh_latency_jump = 0;
+		}
+		if (zh->zh_latency_jump > 3) {
+			zh->zh_latency_jump = 0;
+			zh->zh_swapping = 1;
+		}
+	}
+	return zh->zh_swapping;
+}
+#endif /* SLAP_ZONE_ALLOC */