--- /dev/null
+++ Libc/Libc-391.4.2/include/mpool.h
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+/*-
+ * Copyright (c) 1991, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)mpool.h	8.2 (Berkeley) 7/14/94
+ * $FreeBSD: src/include/mpool.h,v 1.9 2002/03/23 17:24:53 imp Exp $
+ */
+
+#ifndef _MPOOL_H_
+#define _MPOOL_H_
+
+#include <sys/queue.h>
+
+/*
+ * The memory pool scheme is a simple one.  Each in-memory page is referenced
+ * by a bucket which is threaded in up to two of three ways.  All active pages
+ * are threaded on a hash chain (hashed by page number) and an lru chain.
+ * Inactive pages are threaded on a free chain.  Each reference to a memory
+ * pool is handed an opaque MPOOL cookie which stores all of this information.
+ */
+#define	HASHSIZE	128
+#define	HASHKEY(pgno)	((pgno - 1) % HASHSIZE)
+
+/* The BKT structures are the elements of the queues. */
+typedef struct _bkt {
+	TAILQ_ENTRY(_bkt) hq;		/* hash queue */
+	TAILQ_ENTRY(_bkt) q;		/* lru queue */
+	void    *page;			/* page */
+	pgno_t   pgno;			/* page number */
+
+#define	MPOOL_DIRTY	0x01		/* page needs to be written */
+#define	MPOOL_PINNED	0x02		/* page is pinned into memory */
+	u_int8_t flags;			/* flags */
+} BKT;
+
+typedef struct MPOOL {
+	TAILQ_HEAD(_lqh, _bkt) lqh;	/* lru queue head */
+					/* hash queue array */
+	TAILQ_HEAD(_hqh, _bkt) hqh[HASHSIZE];
+	pgno_t	curcache;		/* current number of cached pages */
+	pgno_t	maxcache;		/* max number of cached pages */
+	pgno_t	npages;			/* number of pages in the file */
+	unsigned long	pagesize;	/* file page size */
+	int	fd;			/* file descriptor */
+					/* page in conversion routine */
+	void    (*pgin)(void *, pgno_t, void *);
+					/* page out conversion routine */
+	void    (*pgout)(void *, pgno_t, void *);
+	void	*pgcookie;		/* cookie for page in/out routines */
+#ifdef STATISTICS
+	unsigned long	cachehit;
+	unsigned long	cachemiss;
+	unsigned long	pagealloc;
+	unsigned long	pageflush;
+	unsigned long	pageget;
+	unsigned long	pagenew;
+	unsigned long	pageput;
+	unsigned long	pageread;
+	unsigned long	pagewrite;
+#endif
+} MPOOL;
+
+__BEGIN_DECLS
+MPOOL	*mpool_open(void *, int, pgno_t, pgno_t);
+void	 mpool_filter(MPOOL *, void (*)(void *, pgno_t, void *),
+	    void (*)(void *, pgno_t, void *), void *);
+void	*mpool_new(MPOOL *, pgno_t *);
+void	*mpool_get(MPOOL *, pgno_t, unsigned int);
+int	 mpool_put(MPOOL *, void *, unsigned int);
+int	 mpool_sync(MPOOL *);
+int	 mpool_close(MPOOL *);
+#ifdef STATISTICS
+void	 mpool_stat(MPOOL *);
+#endif
+__END_DECLS
+
+#endif