Asterisk - The Open Source Telephony Project  GIT-master-e8cda4b
mpool.c
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1 /*-
2  * Copyright (c) 1990, 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. All advertising materials mentioning features or use of this software
14  * must display the following acknowledgement:
15  * This product includes software developed by the University of
16  * California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  * may be used to endorse or promote products derived from this software
19  * without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)mpool.c 8.5 (Berkeley) 7/26/94";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/param.h>
39 #include <sys/queue.h>
40 #include <sys/stat.h>
41 
42 #include <errno.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 #include "../include/db.h"
49 
50 #define __MPOOLINTERFACE_PRIVATE
51 #include <mpool.h>
52 
53 #undef __APPLE__
54 
55 #ifndef __APPLE__
56 #define mpool_open __mpool_open
57 #define mpool_filter __mpool_filter
58 #define mpool_new __mpool_new
59 #define mpool_get __mpool_get
60 #define mpool_put __mpool_put
61 #define mpool_sync __mpool_sync
62 #define mpool_close __mpool_close
63 #endif
64 
65 static BKT *mpool_bkt __P((MPOOL *));
66 static BKT *mpool_look __P((MPOOL *, pgno_t));
67 static int mpool_write __P((MPOOL *, BKT *));
68 
69 /*
70  * mpool_open --
71  * Initialize a memory pool.
72  */
73 MPOOL *
74 mpool_open(key, fd, pagesize, maxcache)
75  void *key;
76  int fd;
77  pgno_t pagesize, maxcache;
78 {
79  struct stat sb;
80  MPOOL *mp;
81  int entry;
82 
83  /*
84  * Get information about the file.
85  *
86  * XXX
87  * We don't currently handle pipes, although we should.
88  */
89  if (fstat(fd, &sb))
90  return (NULL);
91  if (!S_ISREG(sb.st_mode)) {
92  errno = ESPIPE;
93  return (NULL);
94  }
95 
96  /* Allocate and initialize the MPOOL cookie. */
97  if ((mp = (MPOOL *)calloc(1, sizeof(MPOOL))) == NULL)
98  return (NULL);
99  CIRCLEQ_INIT(&mp->lqh);
100  for (entry = 0; entry < HASHSIZE; ++entry)
101  CIRCLEQ_INIT(&mp->hqh[entry]);
102  mp->maxcache = maxcache;
103  mp->npages = sb.st_size / pagesize;
104  mp->pagesize = pagesize;
105  mp->fd = fd;
106  return (mp);
107 }
108 
109 /*
110  * mpool_filter --
111  * Initialize input/output filters.
112  */
113 void
114 mpool_filter(mp, pgin, pgout, pgcookie)
115  MPOOL *mp;
116  void (*pgin) __P((void *, pgno_t, void *));
117  void (*pgout) __P((void *, pgno_t, void *));
118  void *pgcookie;
119 {
120  mp->pgin = pgin;
121  mp->pgout = pgout;
122  mp->pgcookie = pgcookie;
123 }
124 
125 /*
126  * mpool_new --
127  * Get a new page of memory.
128  */
129 void *
130 mpool_new(mp, pgnoaddr)
131  MPOOL *mp;
132  pgno_t *pgnoaddr;
133 {
134  struct _hqh *head;
135  BKT *bp;
136 
137  if (mp->npages == MAX_PAGE_NUMBER) {
138  (void)fprintf(stderr, "mpool_new: page allocation overflow.\n");
139  abort();
140  }
141 #ifdef STATISTICS
142  ++mp->pagenew;
143 #endif
144  /*
145  * Get a BKT from the cache. Assign a new page number, attach
146  * it to the head of the hash chain, the tail of the lru chain,
147  * and return.
148  */
149  if ((bp = mpool_bkt(mp)) == NULL)
150  return (NULL);
151  *pgnoaddr = bp->pgno = mp->npages++;
152  bp->flags = MPOOL_PINNED;
153 
154  head = &mp->hqh[HASHKEY(bp->pgno)];
155  CIRCLEQ_INSERT_HEAD(head, bp, hq);
156  CIRCLEQ_INSERT_TAIL(&mp->lqh, bp, q);
157  return (bp->page);
158 }
159 
160 /*
161  * mpool_get
162  * Get a page.
163  */
164 void *
165 mpool_get(mp, pgno, flags)
166  MPOOL *mp;
167  pgno_t pgno;
168  u_int flags; /* XXX not used? */
169 {
170  struct _hqh *head;
171  BKT *bp;
172  off_t off;
173  int nr;
174 
175  /* Check for attempt to retrieve a non-existent page. */
176  if (pgno >= mp->npages) {
177  errno = EINVAL;
178  return (NULL);
179  }
180 
181 #ifdef STATISTICS
182  ++mp->pageget;
183 #endif
184 
185  /* Check for a page that is cached. */
186  if ((bp = mpool_look(mp, pgno)) != NULL) {
187 #ifdef DEBUG
188  if (bp->flags & MPOOL_PINNED) {
189  (void)fprintf(stderr,
190  "mpool_get: page %d already pinned\n", bp->pgno);
191  abort();
192  }
193 #endif
194  /*
195  * Move the page to the head of the hash chain and the tail
196  * of the lru chain.
197  */
198  head = &mp->hqh[HASHKEY(bp->pgno)];
199  CIRCLEQ_REMOVE(head, bp, hq);
200  CIRCLEQ_INSERT_HEAD(head, bp, hq);
201  CIRCLEQ_REMOVE(&mp->lqh, bp, q);
202  CIRCLEQ_INSERT_TAIL(&mp->lqh, bp, q);
203 
204  /* Return a pinned page. */
205  bp->flags |= MPOOL_PINNED;
206  return (bp->page);
207  }
208 
209  /* Get a page from the cache. */
210  if ((bp = mpool_bkt(mp)) == NULL)
211  return (NULL);
212 
213  /* Read in the contents. */
214 #ifdef STATISTICS
215  ++mp->pageread;
216 #endif
217  off = mp->pagesize * pgno;
218  if (lseek(mp->fd, off, SEEK_SET) != off)
219  return (NULL);
220  if ((u_long) (nr = read(mp->fd, bp->page, mp->pagesize))
221  != mp->pagesize) {
222  if (nr >= 0)
223  errno = EFTYPE;
224  return (NULL);
225  }
226 
227  /* Set the page number, pin the page. */
228  bp->pgno = pgno;
229  bp->flags = MPOOL_PINNED;
230 
231  /*
232  * Add the page to the head of the hash chain and the tail
233  * of the lru chain.
234  */
235  head = &mp->hqh[HASHKEY(bp->pgno)];
236  CIRCLEQ_INSERT_HEAD(head, bp, hq);
237  CIRCLEQ_INSERT_TAIL(&mp->lqh, bp, q);
238 
239  /* Run through the user's filter. */
240  if (mp->pgin != NULL)
241  (mp->pgin)(mp->pgcookie, bp->pgno, bp->page);
242 
243  return (bp->page);
244 }
245 
246 /*
247  * mpool_put
248  * Return a page.
249  */
250 int
251 mpool_put(mp, page, flags)
252  MPOOL *mp;
253  void *page;
254  u_int flags;
255 {
256  BKT *bp;
257 
258 #ifdef STATISTICS
259  ++mp->pageput;
260 #endif
261  bp = (BKT *)((char *)page - sizeof(BKT));
262 #ifdef DEBUG
263  if (!(bp->flags & MPOOL_PINNED)) {
264  (void)fprintf(stderr,
265  "mpool_put: page %d not pinned\n", bp->pgno);
266  abort();
267  }
268 #endif
269  bp->flags &= ~MPOOL_PINNED;
270  bp->flags |= flags & MPOOL_DIRTY;
271  return (RET_SUCCESS);
272 }
273 
274 /*
275  * mpool_close
276  * Close the buffer pool.
277  */
278 int
280  MPOOL *mp;
281 {
282  BKT *bp;
283 
284  /* Free up any space allocated to the lru pages. */
285  while ((bp = mp->lqh.cqh_first) != (void *)&mp->lqh) {
286  CIRCLEQ_REMOVE(&mp->lqh, mp->lqh.cqh_first, q);
287  free(bp);
288  }
289 
290  /* Free the MPOOL cookie. */
291  free(mp);
292  return (RET_SUCCESS);
293 }
294 
295 /*
296  * mpool_sync
297  * Sync the pool to disk.
298  */
299 int
301  MPOOL *mp;
302 {
303  BKT *bp;
304 
305  /* Walk the lru chain, flushing any dirty pages to disk. */
306  for (bp = mp->lqh.cqh_first;
307  bp != (void *)&mp->lqh; bp = bp->q.cqe_next)
308  if (bp->flags & MPOOL_DIRTY &&
309  mpool_write(mp, bp) == RET_ERROR)
310  return (RET_ERROR);
311 
312  /* Sync the file descriptor. */
313  return (fsync(mp->fd) ? RET_ERROR : RET_SUCCESS);
314 }
315 
316 #define __APPLE__
317 
318 #ifndef __APPLE__
319 #undef mpool_open
320 #undef mpool_filter
321 #undef mpool_new
322 #undef mpool_get
323 #undef mpool_put
324 #undef mpool_close
325 #undef mpool_sync
326 
327 #define weak_alias(original, alias) \
328  asm (".weak " #alias "\n" #alias " = " #original);
329 weak_alias (__mpool_open, mpool_open)
330 weak_alias (__mpool_filter, mpool_filter)
331 weak_alias (__mpool_new, mpool_new)
332 weak_alias (__mpool_get, mpool_get)
333 weak_alias (__mpool_put, mpool_put)
334 weak_alias (__mpool_close, mpool_close)
335 weak_alias (__mpool_sync, mpool_sync)
336 #endif
337 
338 /*
339  * mpool_bkt
340  * Get a page from the cache (or create one).
341  */
342 static BKT *
344  MPOOL *mp;
345 {
346  struct _hqh *head;
347  BKT *bp;
348 
349  /* If under the max cached, always create a new page. */
350  if (mp->curcache < mp->maxcache)
351  goto new;
352 
353  /*
354  * If the cache is max'd out, walk the lru list for a buffer we
355  * can flush. If we find one, write it (if necessary) and take it
356  * off any lists. If we don't find anything we grow the cache anyway.
357  * The cache never shrinks.
358  */
359  for (bp = mp->lqh.cqh_first;
360  bp != (void *)&mp->lqh; bp = bp->q.cqe_next)
361  if (!(bp->flags & MPOOL_PINNED)) {
362  /* Flush if dirty. */
363  if (bp->flags & MPOOL_DIRTY &&
364  mpool_write(mp, bp) == RET_ERROR)
365  return (NULL);
366 #ifdef STATISTICS
367  ++mp->pageflush;
368 #endif
369  /* Remove from the hash and lru queues. */
370  head = &mp->hqh[HASHKEY(bp->pgno)];
371  CIRCLEQ_REMOVE(head, bp, hq);
372  CIRCLEQ_REMOVE(&mp->lqh, bp, q);
373 #ifdef DEBUG
374  { void *spage;
375  spage = bp->page;
376  memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
377  bp->page = spage;
378  }
379 #endif
380  return (bp);
381  }
382 
383 new: if ((bp = (BKT *) calloc(1, sizeof(BKT) + mp->pagesize)) == NULL)
384  return (NULL);
385 #ifdef STATISTICS
386  ++mp->pagealloc;
387 #endif
388 #if defined(DEBUG) || defined(PURIFY)
389  memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
390 #endif
391  bp->page = (char *)bp + sizeof(BKT);
392  ++mp->curcache;
393  return (bp);
394 }
395 
396 /*
397  * mpool_write
398  * Write a page to disk.
399  */
400 static int
401 mpool_write(mp, bp)
402  MPOOL *mp;
403  BKT *bp;
404 {
405  off_t off;
406 
407 #ifdef STATISTICS
408  ++mp->pagewrite;
409 #endif
410 
411  /* Run through the user's filter. */
412  if (mp->pgout)
413  (mp->pgout)(mp->pgcookie, bp->pgno, bp->page);
414 
415  off = mp->pagesize * bp->pgno;
416  if (lseek(mp->fd, off, SEEK_SET) != off)
417  return (RET_ERROR);
418  if ((u_long) write(mp->fd, bp->page, mp->pagesize) != mp->pagesize)
419  return (RET_ERROR);
420 
421  bp->flags &= ~MPOOL_DIRTY;
422  return (RET_SUCCESS);
423 }
424 
425 /*
426  * mpool_look
427  * Lookup a page in the cache.
428  */
429 static BKT *
430 mpool_look(mp, pgno)
431  MPOOL *mp;
432  pgno_t pgno;
433 {
434  struct _hqh *head;
435  BKT *bp;
436 
437  head = &mp->hqh[HASHKEY(pgno)];
438  for (bp = head->cqh_first; bp != (void *)head; bp = bp->hq.cqe_next)
439  if (bp->pgno == pgno) {
440 #ifdef STATISTICS
441  ++mp->cachehit;
442 #endif
443  return (bp);
444  }
445 #ifdef STATISTICS
446  ++mp->cachemiss;
447 #endif
448  return (NULL);
449 }
450 
451 #ifdef STATISTICS
452 /*
453  * mpool_stat
454  * Print out cache statistics.
455  */
456 void
457 mpool_stat(mp)
458  MPOOL *mp;
459 {
460  BKT *bp;
461  int cnt;
462  char *sep;
463 
464  (void)fprintf(stderr, "%lu pages in the file\n", mp->npages);
465  (void)fprintf(stderr,
466  "page size %lu, cacheing %lu pages of %lu page max cache\n",
467  mp->pagesize, mp->curcache, mp->maxcache);
468  (void)fprintf(stderr, "%lu page puts, %lu page gets, %lu page new\n",
469  mp->pageput, mp->pageget, mp->pagenew);
470  (void)fprintf(stderr, "%lu page allocs, %lu page flushes\n",
471  mp->pagealloc, mp->pageflush);
472  if (mp->cachehit + mp->cachemiss)
473  (void)fprintf(stderr,
474  "%.0f%% cache hit rate (%lu hits, %lu misses)\n",
475  ((double)mp->cachehit / (mp->cachehit + mp->cachemiss))
476  * 100, mp->cachehit, mp->cachemiss);
477  (void)fprintf(stderr, "%lu page reads, %lu page writes\n",
478  mp->pageread, mp->pagewrite);
479 
480  sep = "";
481  cnt = 0;
482  for (bp = mp->lqh.cqh_first;
483  bp != (void *)&mp->lqh; bp = bp->q.cqe_next) {
484  (void)fprintf(stderr, "%s%d", sep, bp->pgno);
485  if (bp->flags & MPOOL_DIRTY)
486  (void)fprintf(stderr, "d");
487  if (bp->flags & MPOOL_PINNED)
488  (void)fprintf(stderr, "P");
489  if (++cnt == 10) {
490  sep = "\n";
491  cnt = 0;
492  } else
493  sep = ", ";
494 
495  }
496  (void)fprintf(stderr, "\n");
497 }
498 #endif
#define mpool_filter
Definition: mpool.c:57
Definition: mpool.h:66
#define mpool_new
Definition: mpool.c:58
#define RET_ERROR
Definition: db.h:51
pgno_t npages
Definition: mpool.h:72
#define mpool_put
Definition: mpool.c:60
#define mpool_sync
Definition: mpool.c:61
#define MPOOL_PINNED
Definition: mpool.h:62
void * pgcookie
Definition: mpool.h:79
#define HASHSIZE
Definition: mpool.h:51
#define NULL
Definition: resample.c:96
void * page
Definition: mpool.h:58
#define calloc(a, b)
Definition: astmm.h:157
#define mpool_close
Definition: mpool.c:62
#define MPOOL_DIRTY
Definition: mpool.h:61
#define MAX_PAGE_NUMBER
Definition: db.h:77
#define mpool_get
Definition: mpool.c:59
static int mpool_write(MPOOL *mp, BKT *bp)
Definition: mpool.c:401
void free()
pgno_t pgno
Definition: mpool.h:59
#define RET_SUCCESS
Definition: db.h:52
static BKT * mpool_look(MPOOL *mp, pgno_t pgno)
Definition: mpool.c:430
pgno_t maxcache
Definition: mpool.h:71
u_int32_t pgno_t
Definition: db.h:78
int fd
Definition: mpool.h:74
int errno
#define CIRCLEQ_REMOVE(head, elm, field)
Definition: queue.h:482
u_long pagesize
Definition: mpool.h:73
#define EFTYPE
#define CIRCLEQ_INSERT_HEAD(head, elm, field)
Definition: queue.h:456
#define HASHKEY(pgno)
Definition: mpool.h:52
Definition: mpool.h:55
#define CIRCLEQ_INSERT_TAIL(head, elm, field)
Definition: queue.h:466
u_int8_t flags
Definition: mpool.h:63
const char * key
Definition: module.h:359
Definition: search.h:40
#define CIRCLEQ_INIT(head)
Definition: queue.h:431
static BKT * mpool_bkt(MPOOL *mp)
Definition: mpool.c:343
pgno_t curcache
Definition: mpool.h:70
#define mpool_open
Definition: mpool.c:56
struct _bkt BKT
static BKT *mpool_bkt __P((MPOOL *))