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authorRoland McGrath <roland@gnu.org>1996-01-02 08:57:42 +0000
committerRoland McGrath <roland@gnu.org>1996-01-02 08:57:42 +0000
commit71733723fb421bd54467d1a27096463ed1dcc2ed (patch)
treef304556d491722c797d876911834dc4afbfa2740 /db/mpool.h
parentfc4026d8e43407ba2739e493878d1ce259500059 (diff)
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* hurd/hurd/signal.h (struct hurd_sigstate): New member `preempters'.cvs/libc-960102
(hurd_preempt_signals, hurd_unpreempt_signals): Decls removed. * hurd/hurd/sigpreempt.h: New file. * hurd/preempt-sig.c: Rewritten with new interface. * sysdeps/mach/hurd/jmp-unwind.c (_longjmp_unwind): Remove local signal preempters being unwound past. * db: New directory, 4.4 BSD db package incorporated from BSD db-1.85 release. * sysdeps/unix/sysv/linux/sys/param.h: Several new macros for BSD compatibility.
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+/*-
+ * 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
+ */
+
+#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 {
+ CIRCLEQ_ENTRY(_bkt) hq; /* hash queue */
+ CIRCLEQ_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 {
+ CIRCLEQ_HEAD(_lqh, _bkt) lqh; /* lru queue head */
+ /* hash queue array */
+ CIRCLEQ_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 */
+ u_long pagesize; /* file page size */
+ int fd; /* file descriptor */
+ /* page in conversion routine */
+ void (*pgin) __P((void *, pgno_t, void *));
+ /* page out conversion routine */
+ void (*pgout) __P((void *, pgno_t, void *));
+ void *pgcookie; /* cookie for page in/out routines */
+#ifdef STATISTICS
+ u_long cachehit;
+ u_long cachemiss;
+ u_long pagealloc;
+ u_long pageflush;
+ u_long pageget;
+ u_long pagenew;
+ u_long pageput;
+ u_long pageread;
+ u_long pagewrite;
+#endif
+} MPOOL;
+
+__BEGIN_DECLS
+MPOOL *mpool_open __P((void *, int, pgno_t, pgno_t));
+void mpool_filter __P((MPOOL *, void (*)(void *, pgno_t, void *),
+ void (*)(void *, pgno_t, void *), void *));
+void *mpool_new __P((MPOOL *, pgno_t *));
+void *mpool_get __P((MPOOL *, pgno_t, u_int));
+int mpool_put __P((MPOOL *, void *, u_int));
+int mpool_sync __P((MPOOL *));
+int mpool_close __P((MPOOL *));
+#ifdef STATISTICS
+void mpool_stat __P((MPOOL *));
+#endif
+__END_DECLS