/include/mpool.h

https://bitbucket.org/freebsd/freebsd-head/ · C++ Header · 109 lines · 56 code · 9 blank · 44 comment · 0 complexity · 51cee3babca7a1be828dc20b0a7a2815 MD5 · raw file 

    

  1. /*-
    2. 

  2.  * Copyright (c) 1991, 1993, 1994
    3. 

  3.  *	The Regents of the University of California.  All rights reserved.
    4. 

  4.  *
    5. 

  5.  * Redistribution and use in source and binary forms, with or without
    6. 

  6.  * modification, are permitted provided that the following conditions
    7. 

  7.  * are met:
    8. 

  8.  * 1. Redistributions of source code must retain the above copyright
    9. 

  9.  *    notice, this list of conditions and the following disclaimer.
    10. 

  10.  * 2. Redistributions in binary form must reproduce the above copyright
    11. 

  11.  *    notice, this list of conditions and the following disclaimer in the
    12. 

  12.  *    documentation and/or other materials provided with the distribution.
    13. 

  13.  * 3. Neither the name of the University nor the names of its contributors
    14. 

  14.  *    may be used to endorse or promote products derived from this software
    15. 

  15.  *    without specific prior written permission.
    16. 

  16.  *
    17. 

  17.  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
    18. 

  18.  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    19. 

  19.  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    20. 

  20.  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
    21. 

  21.  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    22. 

  22.  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    23. 

  23.  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    24. 

  24.  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    25. 

  25.  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    26. 

  26.  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    27. 

  27.  * SUCH DAMAGE.
    28. 

  28.  *
    29. 

  29.  *	@(#)mpool.h	8.4 (Berkeley) 11/2/95
    30. 

  30.  * $FreeBSD$
    31. 

  31.  */
    32. 

  32. 

  33. #ifndef _MPOOL_H_
    34. 

  34. #define _MPOOL_H_
    35. 

  35. 

  36. #include <sys/queue.h>
    37. 

  37. 

  38. /*
    39. 

  39.  * The memory pool scheme is a simple one.  Each in-memory page is referenced
    40. 

  40.  * by a bucket which is threaded in up to two of three ways.  All active pages
    41. 

  41.  * are threaded on a hash chain (hashed by page number) and an lru chain.
    42. 

  42.  * Inactive pages are threaded on a free chain.  Each reference to a memory
    43. 

  43.  * pool is handed an opaque MPOOL cookie which stores all of this information.
    44. 

  44.  */
    45. 

  45. #define	HASHSIZE	128
    46. 

  46. #define	HASHKEY(pgno)	((pgno - 1 + HASHSIZE) % HASHSIZE)
    47. 

  47. 

  48. /* The BKT structures are the elements of the queues. */
    49. 

  49. typedef struct _bkt {
    50. 

  50. 	TAILQ_ENTRY(_bkt) hq;		/* hash queue */
    51. 

  51. 	TAILQ_ENTRY(_bkt) q;		/* lru queue */
    52. 

  52. 	void    *page;			/* page */
    53. 

  53. 	pgno_t   pgno;			/* page number */
    54. 

  54. 

  55. #define	MPOOL_DIRTY	0x01		/* page needs to be written */
    56. 

  56. #define	MPOOL_PINNED	0x02		/* page is pinned into memory */
    57. 

  57. #define	MPOOL_INUSE	0x04		/* page address is valid */
    58. 

  58. 	u_int8_t flags;			/* flags */
    59. 

  59. } BKT;
    60. 

  60. 

  61. typedef struct MPOOL {
    62. 

  62. 	TAILQ_HEAD(_lqh, _bkt) lqh;	/* lru queue head */
    63. 

  63. 					/* hash queue array */
    64. 

  64. 	TAILQ_HEAD(_hqh, _bkt) hqh[HASHSIZE];
    65. 

  65. 	pgno_t	curcache;		/* current number of cached pages */
    66. 

  66. 	pgno_t	maxcache;		/* max number of cached pages */
    67. 

  67. 	pgno_t	npages;			/* number of pages in the file */
    68. 

  68. 	unsigned long	pagesize;	/* file page size */
    69. 

  69. 	int	fd;			/* file descriptor */
    70. 

  70. 					/* page in conversion routine */
    71. 

  71. 	void    (*pgin)(void *, pgno_t, void *);
    72. 

  72. 					/* page out conversion routine */
    73. 

  73. 	void    (*pgout)(void *, pgno_t, void *);
    74. 

  74. 	void	*pgcookie;		/* cookie for page in/out routines */
    75. 

  75. #ifdef STATISTICS
    76. 

  76. 	unsigned long	cachehit;
    77. 

  77. 	unsigned long	cachemiss;
    78. 

  78. 	unsigned long	pagealloc;
    79. 

  79. 	unsigned long	pageflush;
    80. 

  80. 	unsigned long	pageget;
    81. 

  81. 	unsigned long	pagenew;
    82. 

  82. 	unsigned long	pageput;
    83. 

  83. 	unsigned long	pageread;
    84. 

  84. 	unsigned long	pagewrite;
    85. 

  85. #endif
    86. 

  86. } MPOOL;
    87. 

  87. 

  88. #define	MPOOL_IGNOREPIN	0x01		/* Ignore if the page is pinned. */
    89. 

  89. #define	MPOOL_PAGE_REQUEST	0x01	/* Allocate a new page with a
    90. 

  90. 					   specific page number. */
    91. 

  91. #define	MPOOL_PAGE_NEXT		0x02	/* Allocate a new page with the next
    92. 

  92. 					  page number. */
    93. 

  93. 

  94. __BEGIN_DECLS
    95. 

  95. MPOOL	*mpool_open(void *, int, pgno_t, pgno_t);
    96. 

  96. void	 mpool_filter(MPOOL *, void (*)(void *, pgno_t, void *),
    97. 

  97. 	    void (*)(void *, pgno_t, void *), void *);
    98. 

  98. void	*mpool_new(MPOOL *, pgno_t *, unsigned int);
    99. 

  99. void	*mpool_get(MPOOL *, pgno_t, unsigned int);
    100. 

  100. int	 mpool_delete(MPOOL *, void *);
    101. 

  101. int	 mpool_put(MPOOL *, void *, unsigned int);
    102. 

  102. int	 mpool_sync(MPOOL *);
    103. 

  103. int	 mpool_close(MPOOL *);
    104. 

  104. #ifdef STATISTICS
    105. 

  105. void	 mpool_stat(MPOOL *);
    106. 

  106. #endif
    107. 

  107. __END_DECLS
    108. 

  108. 

  109. #endif
    110.