diff --git a/server/mpm/event/config.m4 b/server/mpm/event/config.m4

index c891c75..351f1ac 100644

--- a/server/mpm/event/config.m4

+++ b/server/mpm/event/config.m4

@@ -7,8 +7,6 @@ elif test $have_threaded_sig_graceful != yes; then

     AC_MSG_RESULT(no - SIG_GRACEFUL cannot be used with a threaded MPM)

 elif test $ac_cv_have_threadsafe_pollset != yes; then

     AC_MSG_RESULT(no - APR_POLLSET_THREADSAFE is not supported)

-elif test $apr_has_skiplist != yes; then

-    AC_MSG_RESULT(no - APR skiplist is not available, need APR 1.5.x or later)

 else

     AC_MSG_RESULT(yes)

     APACHE_MPM_SUPPORTED(event, yes, yes)

diff --git a/server/mpm/event/config3.m4 b/server/mpm/event/config3.m4

index 09d3626..722dfcb 100644

--- a/server/mpm/event/config3.m4

+++ b/server/mpm/event/config3.m4

@@ -2,6 +2,6 @@ dnl ## XXX - Need a more thorough check of the proper flags to use

 APACHE_SUBST(MOD_MPM_EVENT_LDADD)

-APACHE_MPM_MODULE(event, $enable_mpm_event, event.lo,[

+APACHE_MPM_MODULE(event, $enable_mpm_event, event.lo apr_skiplist.lo, [

     AC_CHECK_FUNCS(pthread_kill)

 ], , [\$(MOD_MPM_EVENT_LDADD)])

diff --git a/server/mpm/event/apr_skiplist.c b/server/mpm/event/apr_skiplist.c

new file mode 100644

index 0000000..b4696bd

--- /dev/null

+++ b/server/mpm/event/apr_skiplist.c

@@ -0,0 +1,721 @@

+/* Licensed to the Apache Software Foundation (ASF) under one or more

+ * contributor license agreements.  See the NOTICE file distributed with

+ * this work for additional information regarding copyright ownership.

+ * The ASF licenses this file to You under the Apache License, Version 2.0

+ * (the "License"); you may not use this file except in compliance with

+ * the License.  You may obtain a copy of the License at

+ *

+ *     http://www.apache.org/licenses/LICENSE-2.0

+ *

+ * Unless required by applicable law or agreed to in writing, software

+ * distributed under the License is distributed on an "AS IS" BASIS,

+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

+ * See the License for the specific language governing permissions and

+ * limitations under the License.

+ */

+

+/*

+ * Modified to use APR and APR pools.

+ *  TODO: Is malloc() better? Will long running skiplists grow too much?

+ *  Keep the skiplist_alloc() and skiplist_free() until we know

+ *  Yeah, if using pools it means some bogus cycles for checks

+ *  (and an useless function call for skiplist_free) which we

+ *  can removed if/when needed.

+ */

+

+#include "apr_skiplist.h"

+

+typedef struct {

+    apr_skiplistnode **data;

+    size_t size, pos;

+    apr_pool_t *p;

+} apr_skiplist_q; 

+

+struct apr_skiplist {

+    apr_skiplist_compare compare;

+    apr_skiplist_compare comparek;

+    int height;

+    int preheight;

+    size_t size;

+    apr_skiplistnode *top;

+    apr_skiplistnode *bottom;

+    /* These two are needed for appending */

+    apr_skiplistnode *topend;

+    apr_skiplistnode *bottomend;

+    apr_skiplist *index;

+    apr_array_header_t *memlist;

+    apr_skiplist_q nodes_q,

+                   stack_q;

+    apr_pool_t *pool;

+};

+

+struct apr_skiplistnode {

+    void *data;

+    apr_skiplistnode *next;

+    apr_skiplistnode *prev;

+    apr_skiplistnode *down;

+    apr_skiplistnode *up;

+    apr_skiplistnode *previndex;

+    apr_skiplistnode *nextindex;

+    apr_skiplist *sl;

+};

+

+static int get_b_rand(void)

+{

+    static int ph = 32;         /* More bits than we will ever use */

+    static int randseq;

+    if (ph > 31) {              /* Num bits in return of rand() */

+        ph = 0;

+        randseq = rand();

+    }

+    return randseq & (1 << ph++);

+}

+

+typedef struct {

+    size_t size;

+    apr_array_header_t *list;

+} memlist_t;

+

+typedef struct {

+    void *ptr;

+    char inuse;

+} chunk_t;

+

+APR_DECLARE(void *) apr_skiplist_alloc(apr_skiplist *sl, size_t size)

+{

+    if (sl->pool) {

+        void *ptr;

+        int found_size = 0;

+        int i;

+        chunk_t *newchunk;

+        memlist_t *memlist = (memlist_t *)sl->memlist->elts;

+        for (i = 0; i < sl->memlist->nelts; i++) {

+            if (memlist->size == size) {

+                int j;

+                chunk_t *chunk = (chunk_t *)memlist->list->elts;

+                found_size = 1;

+                for (j = 0; j < memlist->list->nelts; j++) {

+                    if (!chunk->inuse) {

+                        chunk->inuse = 1;

+                        return chunk->ptr;

+                    }

+                    chunk++;

+                }

+                break; /* no free of this size; punt */

+            }

+            memlist++;

+        }

+        /* no free chunks */

+        ptr = apr_palloc(sl->pool, size);

+        if (!ptr) {

+            return ptr;

+        }

+        /*

+         * is this a new sized chunk? If so, we need to create a new

+         * array of them. Otherwise, re-use what we already have.

+         */

+        if (!found_size) {

+            memlist = apr_array_push(sl->memlist);

+            memlist->size = size;

+            memlist->list = apr_array_make(sl->pool, 20, sizeof(chunk_t));

+        }

+        newchunk = apr_array_push(memlist->list);

+        newchunk->ptr = ptr;

+        newchunk->inuse = 1;

+        return ptr;

+    }

+    else {

+        return malloc(size);

+    }

+}

+

+APR_DECLARE(void) apr_skiplist_free(apr_skiplist *sl, void *mem)

+{

+    if (!sl->pool) {

+        free(mem);

+    }

+    else {

+        int i;

+        memlist_t *memlist = (memlist_t *)sl->memlist->elts;

+        for (i = 0; i < sl->memlist->nelts; i++) {

+            int j;

+            chunk_t *chunk = (chunk_t *)memlist->list->elts;

+            for (j = 0; j < memlist->list->nelts; j++) {

+                if (chunk->ptr == mem) {

+                    chunk->inuse = 0;

+                    return;

+                }

+                chunk++;

+            }

+            memlist++;

+        }

+    }

+}

+

+static apr_status_t skiplist_qpush(apr_skiplist_q *q, apr_skiplistnode *m)

+{

+    if (q->pos >= q->size) {

+        apr_skiplistnode **data;

+        size_t size = (q->pos) ? q->pos * 2 : 32;

+        if (q->p) {

+            data = apr_palloc(q->p, size * sizeof(*data));

+            if (data) {

+                memcpy(data, q->data, q->pos * sizeof(*data));

+            }

+        }

+        else {

+            data = realloc(q->data, size * sizeof(*data));

+        }

+        if (!data) {

+            return APR_ENOMEM;

+        }

+        q->data = data;

+        q->size = size;

+    }

+    q->data[q->pos++] = m;

+    return APR_SUCCESS;

+}

+

+static APR_INLINE apr_skiplistnode *skiplist_qpop(apr_skiplist_q *q)

+{

+    return (q->pos > 0) ? q->data[--q->pos] : NULL;

+}

+

+static APR_INLINE void skiplist_qclear(apr_skiplist_q *q)

+{

+    q->pos = 0;

+}

+

+static apr_skiplistnode *skiplist_new_node(apr_skiplist *sl)

+{

+    apr_skiplistnode *m = skiplist_qpop(&sl->nodes_q);

+    if (!m) {

+        if (sl->pool) {

+            m = apr_palloc(sl->pool, sizeof *m);

+        }

+        else {

+            m = malloc(sizeof *m);

+        }

+    }

+    return m;

+}

+

+static apr_status_t skiplist_free_node(apr_skiplist *sl, apr_skiplistnode *m)

+{

+    return skiplist_qpush(&sl->nodes_q, m);

+}

+

+static apr_status_t skiplisti_init(apr_skiplist **s, apr_pool_t *p)

+{

+    apr_skiplist *sl;

+    if (p) {

+        sl = apr_pcalloc(p, sizeof(apr_skiplist));

+        sl->memlist = apr_array_make(p, 20, sizeof(memlist_t));

+        sl->pool = sl->nodes_q.p = sl->stack_q.p = p;

+    }

+    else {

+        sl = calloc(1, sizeof(apr_skiplist));

+        if (!sl) {

+            return APR_ENOMEM;

+        }

+    }

+    *s = sl;

+    return APR_SUCCESS;

+}

+

+static int indexing_comp(void *a, void *b)

+{

+    void *ac = (void *) (((apr_skiplist *) a)->compare);

+    void *bc = (void *) (((apr_skiplist *) b)->compare);

+    return ((ac < bc) ? -1 : ((ac > bc) ? 1 : 0));

+}

+

+static int indexing_compk(void *ac, void *b)

+{

+    void *bc = (void *) (((apr_skiplist *) b)->compare);

+    return ((ac < bc) ? -1 : ((ac > bc) ? 1 : 0));

+}

+

+APR_DECLARE(apr_status_t) apr_skiplist_init(apr_skiplist **s, apr_pool_t *p)

+{

+    apr_skiplist *sl;

+    skiplisti_init(s, p);

+    sl = *s;

+    skiplisti_init(&(sl->index), p);

+    apr_skiplist_set_compare(sl->index, indexing_comp, indexing_compk);

+    return APR_SUCCESS;

+}

+

+APR_DECLARE(void) apr_skiplist_set_compare(apr_skiplist *sl,

+                          apr_skiplist_compare comp,

+                          apr_skiplist_compare compk)

+{

+    if (sl->compare && sl->comparek) {

+        apr_skiplist_add_index(sl, comp, compk);

+    }

+    else {

+        sl->compare = comp;

+        sl->comparek = compk;

+    }

+}

+

+APR_DECLARE(void) apr_skiplist_add_index(apr_skiplist *sl,

+                        apr_skiplist_compare comp,

+                        apr_skiplist_compare compk)

+{

+    apr_skiplistnode *m;

+    apr_skiplist *ni;

+    int icount = 0;

+    apr_skiplist_find(sl->index, (void *)comp, &m);

+    if (m) {

+        return;                 /* Index already there! */

+    }

+    skiplisti_init(&ni, sl->pool);

+    apr_skiplist_set_compare(ni, comp, compk);

+    /* Build the new index... This can be expensive! */

+    m = apr_skiplist_insert(sl->index, ni);

+    while (m->prev) {

+        m = m->prev;

+        icount++;

+    }

+    for (m = apr_skiplist_getlist(sl); m; apr_skiplist_next(sl, &m)) {

+        int j = icount - 1;

+        apr_skiplistnode *nsln;

+        nsln = apr_skiplist_insert(ni, m->data);

+        /* skip from main index down list */

+        while (j > 0) {

+            m = m->nextindex;

+            j--;

+        }

+        /* insert this node in the indexlist after m */

+        nsln->nextindex = m->nextindex;

+        if (m->nextindex) {

+            m->nextindex->previndex = nsln;

+        }

+        nsln->previndex = m;

+        m->nextindex = nsln;

+    }

+}

+

+static int skiplisti_find_compare(apr_skiplist *sl, void *data,

+                           apr_skiplistnode **ret,

+                           apr_skiplist_compare comp)

+{

+    int count = 0;

+    apr_skiplistnode *m;

+    m = sl->top;

+    while (m) {

+        if (m->next) {

+            int compared = comp(data, m->next->data);

+            if (compared == 0) {

+                m = m->next;

+                while (m->down) {

+                    m = m->down;

+                }

+                *ret = m;

+                return count;

+            }

+            if (compared > 0) {

+                m = m->next;

+                count++;

+                continue;

+            }

+        }

+        m = m->down;

+        count++;

+    }

+    *ret = NULL;

+    return count;

+}

+

+APR_DECLARE(void *) apr_skiplist_find_compare(apr_skiplist *sli, void *data,

+                               apr_skiplistnode **iter,

+                               apr_skiplist_compare comp)

+{

+    apr_skiplistnode *m;

+    apr_skiplist *sl;

+    if (!comp) {

+        if (iter) {

+            *iter = NULL;

+        }

+        return NULL;

+    }

+    if (comp == sli->compare || !sli->index) {

+        sl = sli;

+    }

+    else {

+        apr_skiplist_find(sli->index, (void *)comp, &m);

+        if (!m) {

+            if (iter) {

+                *iter = NULL;

+            }

+            return NULL;

+        }

+        sl = (apr_skiplist *) m->data;

+    }

+    skiplisti_find_compare(sl, data, &m, sl->comparek);

+    if (iter) {

+        *iter = m;

+    }

+    return (m) ? m->data : NULL;

+}

+

+APR_DECLARE(void *) apr_skiplist_find(apr_skiplist *sl, void *data, apr_skiplistnode **iter)

+{

+    return apr_skiplist_find_compare(sl, data, iter, sl->compare);

+}

+

+

+APR_DECLARE(apr_skiplistnode *) apr_skiplist_getlist(apr_skiplist *sl)

+{

+    if (!sl->bottom) {

+        return NULL;

+    }

+    return sl->bottom->next;

+}

+

+APR_DECLARE(void *) apr_skiplist_next(apr_skiplist *sl, apr_skiplistnode **iter)

+{

+    if (!*iter) {

+        return NULL;

+    }

+    *iter = (*iter)->next;

+    return (*iter) ? ((*iter)->data) : NULL;

+}

+

+APR_DECLARE(void *) apr_skiplist_previous(apr_skiplist *sl, apr_skiplistnode **iter)

+{

+    if (!*iter) {

+        return NULL;

+    }

+    *iter = (*iter)->prev;

+    return (*iter) ? ((*iter)->data) : NULL;

+}

+

+static APR_INLINE int skiplist_height(const apr_skiplist *sl)

+{

+    /* Skiplists (even empty) always have a top node, although this

+     * implementation defers its creation until the first insert, or

+     * deletes it with the last remove. We want the real height here.

+     */

+    return sl->height ? sl->height : 1;

+}

+

+APR_DECLARE(apr_skiplistnode *) apr_skiplist_insert_compare(apr_skiplist *sl, void *data,

+                                      apr_skiplist_compare comp)

+{

+    apr_skiplistnode *m, *p, *tmp, *ret = NULL;

+    int ch, nh = 1;

+

+    if (!comp) {

+        return NULL;

+    }

+

+    ch = skiplist_height(sl);

+    if (sl->preheight) {

+        while (nh < sl->preheight && get_b_rand()) {

+            nh++;

+        }

+    }

+    else {

+        while (nh <= ch && get_b_rand()) {

+            nh++;

+        }

+    }

+

+    /* Now we have in nh the height at which we wish to insert our new node,

+     * and in ch the current height: don't create skip paths to the inserted

+     * element until the walk down through the tree (which decrements ch)

+     * reaches nh. From there, any walk down pushes the current node on a

+     * stack (the node(s) after which we would insert) to pop back through

+     * for insertion later.

+     */

+    m = sl->top;

+    while (m) {

+        if (m->next) {

+            int compared = comp(data, m->next->data);

+            if (compared == 0) {

+                /* Keep the existing element(s) */

+                skiplist_qclear(&sl->stack_q);

+                return NULL;

+            }

+            if (compared > 0) {

+                m = m->next;

+                continue;

+            }

+        }

+        if (ch <= nh) {

+            /* push on stack */

+            skiplist_qpush(&sl->stack_q, m);

+        }

+        m = m->down;

+        ch--;

+    }

+    /* Pop the stack and insert nodes */

+    p = NULL;

+    while ((m = skiplist_qpop(&sl->stack_q))) {

+        tmp = skiplist_new_node(sl);

+        tmp->next = m->next;

+        if (m->next) {

+            m->next->prev = tmp;

+        }

+        m->next = tmp;

+        tmp->prev = m;

+        tmp->up = NULL;

+        tmp->nextindex = tmp->previndex = NULL;

+        tmp->down = p;

+        if (p) {

+            p->up = tmp;

+        }

+        else {

+            /* This sets ret to the bottom-most node we are inserting */

+            ret = tmp;

+        }

+        tmp->data = data;

+        tmp->sl = sl;

+        p = tmp;

+    }

+

+    /* Now we are sure the node is inserted, grow our tree to 'nh' tall */

+    for (; sl->height < nh; sl->height++) {

+        m = skiplist_new_node(sl);

+        tmp = skiplist_new_node(sl);

+        m->up = m->prev = m->nextindex = m->previndex = NULL;

+        m->next = tmp;

+        m->down = sl->top;

+        m->data = NULL;

+        m->sl = sl;

+        if (sl->top) {

+            sl->top->up = m;

+        }

+        else {

+            sl->bottom = sl->bottomend = m;

+        }

+        sl->top = sl->topend = tmp->prev = m;

+        tmp->up = tmp->next = tmp->nextindex = tmp->previndex = NULL;

+        tmp->down = p;

+        tmp->data = data;

+        tmp->sl = sl;

+        if (p) {

+            p->up = tmp;

+        }

+        else {

+            /* This sets ret to the bottom-most node we are inserting */

+            ret = tmp;

+        }

+        p = tmp;

+    }

+    if (sl->index != NULL) {

+        /*

+         * this is a external insertion, we must insert into each index as

+         * well

+         */

+        apr_skiplistnode *ni, *li;

+        li = ret;

+        for (p = apr_skiplist_getlist(sl->index); p; apr_skiplist_next(sl->index, &p)) {

+            apr_skiplist *sli = (apr_skiplist *)p->data;

+            ni = apr_skiplist_insert_compare(sli, ret->data, sli->compare);

+            li->nextindex = ni;

+            ni->previndex = li;

+            li = ni;

+        }

+    }

+    sl->size++;

+    return ret;

+}

+

+APR_DECLARE(apr_skiplistnode *) apr_skiplist_insert(apr_skiplist *sl, void *data)

+{

+    return apr_skiplist_insert_compare(sl, data, sl->compare);

+}

+

+#if 0

+void skiplist_print_struct(apr_skiplist * sl, char *prefix)

+{

+    apr_skiplistnode *p, *q;

+    fprintf(stderr, "Skiplist Structure (height: %d)\n", sl->height);

+    p = sl->bottom;

+    while (p) {

+        q = p;

+        fprintf(stderr, prefix);

+        while (q) {

+            fprintf(stderr, "%p ", q->data);

+            q = q->up;

+        }

+        fprintf(stderr, "\n");

+        p = p->next;

+    }

+}

+#endif

+

+static int skiplisti_remove(apr_skiplist *sl, apr_skiplistnode *m, apr_skiplist_freefunc myfree)

+{

+    apr_skiplistnode *p;

+    if (!m) {

+        return 0;

+    }

+    if (m->nextindex) {

+        skiplisti_remove(m->nextindex->sl, m->nextindex, NULL);

+    }

+    while (m->up) {

+        m = m->up;

+    }

+    while (m) {

+        p = m;

+        p->prev->next = p->next;/* take me out of the list */

+        if (p->next) {

+            p->next->prev = p->prev;    /* take me out of the list */

+        }

+        m = m->down;

+        /* This only frees the actual data in the bottom one */

+        if (!m && myfree && p->data) {

+            myfree(p->data);

+        }

+        skiplist_free_node(sl, p);

+    }

+    sl->size--;

+    while (sl->top && sl->top->next == NULL) {

+        /* While the row is empty and we are not on the bottom row */

+        p = sl->top;

+        sl->top = sl->top->down;/* Move top down one */

+        if (sl->top) {

+            sl->top->up = NULL; /* Make it think its the top */

+        }

+        skiplist_free_node(sl, p);

+        sl->height--;

+    }

+    if (!sl->top) {

+        sl->bottom = sl->bottomend = NULL;

+        sl->topend = NULL;

+    }

+    return skiplist_height(sl);

+}

+

+APR_DECLARE(int) apr_skiplist_remove_compare(apr_skiplist *sli,

+                            void *data,

+                            apr_skiplist_freefunc myfree, apr_skiplist_compare comp)

+{

+    apr_skiplistnode *m;

+    apr_skiplist *sl;

+    if (!comp) {

+        return 0;

+    }

+    if (comp == sli->comparek || !sli->index) {

+        sl = sli;

+    }

+    else {

+        apr_skiplist_find(sli->index, (void *)comp, &m);

+        if (!m) {

+            return 0;

+        }

+        sl = (apr_skiplist *) m->data;

+    }

+    skiplisti_find_compare(sl, data, &m, comp);

+    if (!m) {

+        return 0;

+    }

+    while (m->previndex) {

+        m = m->previndex;

+    }

+    return skiplisti_remove(sl, m, myfree);

+}

+

+APR_DECLARE(int) apr_skiplist_remove(apr_skiplist *sl, void *data, apr_skiplist_freefunc myfree)

+{

+    return apr_skiplist_remove_compare(sl, data, myfree, sl->comparek);

+}

+

+APR_DECLARE(void) apr_skiplist_remove_all(apr_skiplist *sl, apr_skiplist_freefunc myfree)

+{

+    /*

+     * This must remove even the place holder nodes (bottom though top)

+     * because we specify in the API that one can free the Skiplist after

+     * making this call without memory leaks

+     */

+    apr_skiplistnode *m, *p, *u;

+    m = sl->bottom;

+    while (m) {

+        p = m->next;

+        if (myfree && p && p->data) {

+            myfree(p->data);

+        }

+        do {

+            u = m->up;

+            skiplist_free_node(sl, m);

+            m = u;

+        } while (m);

+        m = p;

+    }

+    sl->top = sl->bottom = NULL;

+    sl->topend = sl->bottomend = NULL;

+    sl->height = 0;

+    sl->size = 0;

+}

+

+APR_DECLARE(void *) apr_skiplist_pop(apr_skiplist *a, apr_skiplist_freefunc myfree)

+{

+    apr_skiplistnode *sln;

+    void *data = NULL;

+    sln = apr_skiplist_getlist(a);

+    if (sln) {

+        data = sln->data;

+        skiplisti_remove(a, sln, myfree);

+    }

+    return data;

+}

+

+APR_DECLARE(void *) apr_skiplist_peek(apr_skiplist *a)

+{

+    apr_skiplistnode *sln;

+    sln = apr_skiplist_getlist(a);

+    if (sln) {

+        return sln->data;

+    }

+    return NULL;

+}

+

+static void skiplisti_destroy(void *vsl)

+{

+    apr_skiplist_destroy(vsl, NULL);

+}

+

+APR_DECLARE(void) apr_skiplist_destroy(apr_skiplist *sl, apr_skiplist_freefunc myfree)

+{

+    while (apr_skiplist_pop(sl->index, skiplisti_destroy) != NULL)

+        ;

+    apr_skiplist_remove_all(sl, myfree);

+    if (!sl->pool) {

+        while (sl->nodes_q.pos)

+            free(sl->nodes_q.data[--sl->nodes_q.pos]);