The Tor Browser: security/nss/lib/dbm/include/mpool.h@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /*-

     2  * Copyright (c) 1991, 1993, 1994

     3  *	The Regents of the University of California.  All rights reserved.

     4  *

     5  * Redistribution and use in source and binary forms, with or without

     6  * modification, are permitted provided that the following conditions

     7  * are met:

     8  * 1. Redistributions of source code must retain the above copyright

     9  *    notice, this list of conditions and the following disclaimer.

    10  * 2. Redistributions in binary form must reproduce the above copyright

    11  *    notice, this list of conditions and the following disclaimer in the

    12  *    documentation and/or other materials provided with the distribution.

    13  * 3. ***REMOVED*** - see

    14  *    ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change

    15  * 4. Neither the name of the University nor the names of its contributors

    16  *    may be used to endorse or promote products derived from this software

    17  *    without specific prior written permission.

    18  *

    19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

    20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

    23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

    24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

    25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

    26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

    27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

    28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

    29  * SUCH DAMAGE.

    30  *

    31  *	@(#)mpool.h	8.2 (Berkeley) 7/14/94

    32  */

    34 #include <sys/queue.h>

    36 /*

    37  * The memory pool scheme is a simple one.  Each in-memory page is referenced

    38  * by a bucket which is threaded in up to two of three ways.  All active pages

    39  * are threaded on a hash chain (hashed by page number) and an lru chain.

    40  * Inactive pages are threaded on a free chain.  Each reference to a memory

    41  * pool is handed an opaque MPOOL cookie which stores all of this information.

    42  */

    43 #define	HASHSIZE	128

    44 #define	HASHKEY(pgno)	((pgno - 1) % HASHSIZE)

    46 /* The BKT structures are the elements of the queues. */

    47 typedef struct _bkt {

    48 	CIRCLEQ_ENTRY(_bkt) hq;		/* hash queue */

    49 	CIRCLEQ_ENTRY(_bkt) q;		/* lru queue */

    50 	void    *page;			/* page */

    51 	pgno_t   pgno;			/* page number */

    53 #define	MPOOL_DIRTY	0x01		/* page needs to be written */

    54 #define	MPOOL_PINNED	0x02		/* page is pinned into memory */

    55 	uint8 flags;			/* flags */

    56 } BKT;

    58 typedef struct MPOOL {

    59 	CIRCLEQ_HEAD(_lqh, _bkt) lqh;	/* lru queue head */

    60 					/* hash queue array */

    61 	CIRCLEQ_HEAD(_hqh, _bkt) hqh[HASHSIZE];

    62 	pgno_t	curcache;		/* current number of cached pages */

    63 	pgno_t	maxcache;		/* max number of cached pages */

    64 	pgno_t	npages;			/* number of pages in the file */

    65 	uint32	pagesize;		/* file page size */

    66 	int	fd;			/* file descriptor */

    67 					/* page in conversion routine */

    68 	void    (*pgin) (void *, pgno_t, void *);

    69 					/* page out conversion routine */

    70 	void    (*pgout) (void *, pgno_t, void *);

    71 	void	*pgcookie;		/* cookie for page in/out routines */

    72 #ifdef STATISTICS

    73 	uint32	cachehit;

    74 	uint32	cachemiss;

    75 	uint32	pagealloc;

    76 	uint32	pageflush;

    77 	uint32	pageget;

    78 	uint32	pagenew;

    79 	uint32	pageput;

    80 	uint32	pageread;

    81 	uint32	pagewrite;

    82 #endif

    83 } MPOOL;

    85 __BEGIN_DECLS

    86 MPOOL	*mpool_open (void *, int, pgno_t, pgno_t);

    87 void	 mpool_filter (MPOOL *, void (*)(void *, pgno_t, void *),

    88 	    void (*)(void *, pgno_t, void *), void *);

    89 void	*mpool_new (MPOOL *, pgno_t *);

    90 void	*mpool_get (MPOOL *, pgno_t, uint);

    91 int	 mpool_put (MPOOL *, void *, uint);

    92 int	 mpool_sync (MPOOL *);

    93 int	 mpool_close (MPOOL *);

    94 #ifdef STATISTICS

    95 void	 mpool_stat (MPOOL *);

    96 #endif

    97 __END_DECLS

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