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Diffstat (limited to 'lib/libc/db/mpool/mpool.c')
-rw-r--r--lib/libc/db/mpool/mpool.c433
1 files changed, 252 insertions, 181 deletions
diff --git a/lib/libc/db/mpool/mpool.c b/lib/libc/db/mpool/mpool.c
index a61041e09160..562c7f5e98fc 100644
--- a/lib/libc/db/mpool/mpool.c
+++ b/lib/libc/db/mpool/mpool.c
@@ -1,5 +1,5 @@
/*-
- * Copyright (c) 1990, 1993, 1994
+ * Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -32,11 +32,10 @@
*/
#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)mpool.c 8.5 (Berkeley) 7/26/94";
+static char sccsid[] = "@(#)mpool.c 8.2 (Berkeley) 2/21/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
-#include <sys/queue.h>
#include <sys/stat.h>
#include <errno.h>
@@ -46,21 +45,31 @@ static char sccsid[] = "@(#)mpool.c 8.5 (Berkeley) 7/26/94";
#include <unistd.h>
#include <db.h>
-
#define __MPOOLINTERFACE_PRIVATE
-#include <mpool.h>
+#include "mpool.h"
static BKT *mpool_bkt __P((MPOOL *));
static BKT *mpool_look __P((MPOOL *, pgno_t));
static int mpool_write __P((MPOOL *, BKT *));
+#ifdef DEBUG
+static void __mpoolerr __P((const char *fmt, ...));
+#endif
/*
- * mpool_open --
- * Initialize a memory pool.
+ * MPOOL_OPEN -- initialize a memory pool.
+ *
+ * Parameters:
+ * key: Shared buffer key.
+ * fd: File descriptor.
+ * pagesize: File page size.
+ * maxcache: Max number of cached pages.
+ *
+ * Returns:
+ * MPOOL pointer, NULL on error.
*/
MPOOL *
mpool_open(key, fd, pagesize, maxcache)
- void *key;
+ DBT *key;
int fd;
pgno_t pagesize, maxcache;
{
@@ -68,35 +77,49 @@ mpool_open(key, fd, pagesize, maxcache)
MPOOL *mp;
int entry;
- /*
- * Get information about the file.
- *
- * XXX
- * We don't currently handle pipes, although we should.
- */
if (fstat(fd, &sb))
return (NULL);
+ /* XXX
+ * We should only set st_size to 0 for pipes -- 4.4BSD has the fix so
+ * that stat(2) returns true for ISSOCK on pipes. Until then, this is
+ * fairly close.
+ */
if (!S_ISREG(sb.st_mode)) {
errno = ESPIPE;
return (NULL);
}
- /* Allocate and initialize the MPOOL cookie. */
- if ((mp = (MPOOL *)calloc(1, sizeof(MPOOL))) == NULL)
+ if ((mp = (MPOOL *)malloc(sizeof(MPOOL))) == NULL)
return (NULL);
- CIRCLEQ_INIT(&mp->lqh);
+ mp->free.cnext = mp->free.cprev = (BKT *)&mp->free;
+ mp->lru.cnext = mp->lru.cprev = (BKT *)&mp->lru;
for (entry = 0; entry < HASHSIZE; ++entry)
- CIRCLEQ_INIT(&mp->hqh[entry]);
+ mp->hashtable[entry].hnext = mp->hashtable[entry].hprev =
+ mp->hashtable[entry].cnext = mp->hashtable[entry].cprev =
+ (BKT *)&mp->hashtable[entry];
+ mp->curcache = 0;
mp->maxcache = maxcache;
- mp->npages = sb.st_size / pagesize;
mp->pagesize = pagesize;
+ mp->npages = sb.st_size / pagesize;
mp->fd = fd;
+ mp->pgcookie = NULL;
+ mp->pgin = mp->pgout = NULL;
+
+#ifdef STATISTICS
+ mp->cachehit = mp->cachemiss = mp->pagealloc = mp->pageflush =
+ mp->pageget = mp->pagenew = mp->pageput = mp->pageread =
+ mp->pagewrite = 0;
+#endif
return (mp);
}
/*
- * mpool_filter --
- * Initialize input/output filters.
+ * MPOOL_FILTER -- initialize input/output filters.
+ *
+ * Parameters:
+ * pgin: Page in conversion routine.
+ * pgout: Page out conversion routine.
+ * pgcookie: Cookie for page in/out routines.
*/
void
mpool_filter(mp, pgin, pgout, pgcookie)
@@ -109,130 +132,126 @@ mpool_filter(mp, pgin, pgout, pgcookie)
mp->pgout = pgout;
mp->pgcookie = pgcookie;
}
-
+
/*
- * mpool_new --
- * Get a new page of memory.
+ * MPOOL_NEW -- get a new page
+ *
+ * Parameters:
+ * mp: mpool cookie
+ * pgnoadddr: place to store new page number
+ * Returns:
+ * RET_ERROR, RET_SUCCESS
*/
void *
mpool_new(mp, pgnoaddr)
MPOOL *mp;
pgno_t *pgnoaddr;
{
- struct _hqh *head;
- BKT *bp;
+ BKT *b;
+ BKTHDR *hp;
- if (mp->npages == MAX_PAGE_NUMBER) {
- (void)fprintf(stderr, "mpool_new: page allocation overflow.\n");
- abort();
- }
#ifdef STATISTICS
++mp->pagenew;
#endif
/*
- * Get a BKT from the cache. Assign a new page number, attach
- * it to the head of the hash chain, the tail of the lru chain,
- * and return.
+ * Get a BKT from the cache. Assign a new page number, attach it to
+ * the hash and lru chains and return.
*/
- if ((bp = mpool_bkt(mp)) == NULL)
+ if ((b = mpool_bkt(mp)) == NULL)
return (NULL);
- *pgnoaddr = bp->pgno = mp->npages++;
- bp->flags = MPOOL_PINNED;
-
- head = &mp->hqh[HASHKEY(bp->pgno)];
- CIRCLEQ_INSERT_HEAD(head, bp, hq);
- CIRCLEQ_INSERT_TAIL(&mp->lqh, bp, q);
- return (bp->page);
+ *pgnoaddr = b->pgno = mp->npages++;
+ b->flags = MPOOL_PINNED;
+ inshash(b, b->pgno);
+ inschain(b, &mp->lru);
+ return (b->page);
}
/*
- * mpool_get
- * Get a page.
+ * MPOOL_GET -- get a page from the pool
+ *
+ * Parameters:
+ * mp: mpool cookie
+ * pgno: page number
+ * flags: not used
+ *
+ * Returns:
+ * RET_ERROR, RET_SUCCESS
*/
void *
mpool_get(mp, pgno, flags)
MPOOL *mp;
pgno_t pgno;
- u_int flags; /* XXX not used? */
+ u_int flags; /* XXX not used? */
{
- struct _hqh *head;
- BKT *bp;
+ BKT *b;
+ BKTHDR *hp;
off_t off;
int nr;
- /* Check for attempt to retrieve a non-existent page. */
- if (pgno >= mp->npages) {
- errno = EINVAL;
- return (NULL);
- }
-
+ /*
+ * If asking for a specific page that is already in the cache, find
+ * it and return it.
+ */
+ if (b = mpool_look(mp, pgno)) {
#ifdef STATISTICS
- ++mp->pageget;
+ ++mp->pageget;
#endif
-
- /* Check for a page that is cached. */
- if ((bp = mpool_look(mp, pgno)) != NULL) {
#ifdef DEBUG
- if (bp->flags & MPOOL_PINNED) {
- (void)fprintf(stderr,
- "mpool_get: page %d already pinned\n", bp->pgno);
- abort();
- }
+ if (b->flags & MPOOL_PINNED)
+ __mpoolerr("mpool_get: page %d already pinned",
+ b->pgno);
#endif
- /*
- * Move the page to the head of the hash chain and the tail
- * of the lru chain.
- */
- head = &mp->hqh[HASHKEY(bp->pgno)];
- CIRCLEQ_REMOVE(head, bp, hq);
- CIRCLEQ_INSERT_HEAD(head, bp, hq);
- CIRCLEQ_REMOVE(&mp->lqh, bp, q);
- CIRCLEQ_INSERT_TAIL(&mp->lqh, bp, q);
-
- /* Return a pinned page. */
- bp->flags |= MPOOL_PINNED;
- return (bp->page);
+ rmchain(b);
+ inschain(b, &mp->lru);
+ b->flags |= MPOOL_PINNED;
+ return (b->page);
+ }
+
+ /* Not allowed to retrieve a non-existent page. */
+ if (pgno >= mp->npages) {
+ errno = EINVAL;
+ return (NULL);
}
/* Get a page from the cache. */
- if ((bp = mpool_bkt(mp)) == NULL)
+ if ((b = mpool_bkt(mp)) == NULL)
return (NULL);
+ b->pgno = pgno;
+ b->flags = MPOOL_PINNED;
- /* Read in the contents. */
#ifdef STATISTICS
++mp->pageread;
#endif
+ /* Read in the contents. */
off = mp->pagesize * pgno;
if (lseek(mp->fd, off, SEEK_SET) != off)
return (NULL);
- if ((nr = read(mp->fd, bp->page, mp->pagesize)) != mp->pagesize) {
+ if ((nr = read(mp->fd, b->page, mp->pagesize)) != mp->pagesize) {
if (nr >= 0)
errno = EFTYPE;
return (NULL);
}
+ if (mp->pgin)
+ (mp->pgin)(mp->pgcookie, b->pgno, b->page);
- /* Set the page number, pin the page. */
- bp->pgno = pgno;
- bp->flags = MPOOL_PINNED;
-
- /*
- * Add the page to the head of the hash chain and the tail
- * of the lru chain.
- */
- head = &mp->hqh[HASHKEY(bp->pgno)];
- CIRCLEQ_INSERT_HEAD(head, bp, hq);
- CIRCLEQ_INSERT_TAIL(&mp->lqh, bp, q);
-
- /* Run through the user's filter. */
- if (mp->pgin != NULL)
- (mp->pgin)(mp->pgcookie, bp->pgno, bp->page);
-
- return (bp->page);
+ inshash(b, b->pgno);
+ inschain(b, &mp->lru);
+#ifdef STATISTICS
+ ++mp->pageget;
+#endif
+ return (b->page);
}
/*
- * mpool_put
- * Return a page.
+ * MPOOL_PUT -- return a page to the pool
+ *
+ * Parameters:
+ * mp: mpool cookie
+ * page: page pointer
+ * pgno: page number
+ *
+ * Returns:
+ * RET_ERROR, RET_SUCCESS
*/
int
mpool_put(mp, page, flags)
@@ -240,172 +259,193 @@ mpool_put(mp, page, flags)
void *page;
u_int flags;
{
- BKT *bp;
+ BKT *baddr;
+#ifdef DEBUG
+ BKT *b;
+#endif
#ifdef STATISTICS
++mp->pageput;
#endif
- bp = (BKT *)((char *)page - sizeof(BKT));
+ baddr = (BKT *)((char *)page - sizeof(BKT));
#ifdef DEBUG
- if (!(bp->flags & MPOOL_PINNED)) {
- (void)fprintf(stderr,
- "mpool_put: page %d not pinned\n", bp->pgno);
- abort();
+ if (!(baddr->flags & MPOOL_PINNED))
+ __mpoolerr("mpool_put: page %d not pinned", b->pgno);
+ for (b = mp->lru.cnext; b != (BKT *)&mp->lru; b = b->cnext) {
+ if (b == (BKT *)&mp->lru)
+ __mpoolerr("mpool_put: %0x: bad address", baddr);
+ if (b == baddr)
+ break;
}
#endif
- bp->flags &= ~MPOOL_PINNED;
- bp->flags |= flags & MPOOL_DIRTY;
+ baddr->flags &= ~MPOOL_PINNED;
+ baddr->flags |= flags & MPOOL_DIRTY;
return (RET_SUCCESS);
}
/*
- * mpool_close
- * Close the buffer pool.
+ * MPOOL_CLOSE -- close the buffer pool
+ *
+ * Parameters:
+ * mp: mpool cookie
+ *
+ * Returns:
+ * RET_ERROR, RET_SUCCESS
*/
int
mpool_close(mp)
MPOOL *mp;
{
- BKT *bp;
+ BKT *b, *next;
/* Free up any space allocated to the lru pages. */
- while ((bp = mp->lqh.cqh_first) != (void *)&mp->lqh) {
- CIRCLEQ_REMOVE(&mp->lqh, mp->lqh.cqh_first, q);
- free(bp);
+ for (b = mp->lru.cprev; b != (BKT *)&mp->lru; b = next) {
+ next = b->cprev;
+ free(b);
}
-
- /* Free the MPOOL cookie. */
free(mp);
return (RET_SUCCESS);
}
/*
- * mpool_sync
- * Sync the pool to disk.
+ * MPOOL_SYNC -- sync the file to disk.
+ *
+ * Parameters:
+ * mp: mpool cookie
+ *
+ * Returns:
+ * RET_ERROR, RET_SUCCESS
*/
int
mpool_sync(mp)
MPOOL *mp;
{
- BKT *bp;
+ BKT *b;
- /* Walk the lru chain, flushing any dirty pages to disk. */
- for (bp = mp->lqh.cqh_first;
- bp != (void *)&mp->lqh; bp = bp->q.cqe_next)
- if (bp->flags & MPOOL_DIRTY &&
- mpool_write(mp, bp) == RET_ERROR)
+ for (b = mp->lru.cprev; b != (BKT *)&mp->lru; b = b->cprev)
+ if (b->flags & MPOOL_DIRTY && mpool_write(mp, b) == RET_ERROR)
return (RET_ERROR);
-
- /* Sync the file descriptor. */
return (fsync(mp->fd) ? RET_ERROR : RET_SUCCESS);
}
/*
- * mpool_bkt
- * Get a page from the cache (or create one).
+ * MPOOL_BKT -- get/create a BKT from the cache
+ *
+ * Parameters:
+ * mp: mpool cookie
+ *
+ * Returns:
+ * NULL on failure and a pointer to the BKT on success
*/
static BKT *
mpool_bkt(mp)
MPOOL *mp;
{
- struct _hqh *head;
- BKT *bp;
+ BKT *b;
- /* If under the max cached, always create a new page. */
if (mp->curcache < mp->maxcache)
goto new;
/*
- * If the cache is max'd out, walk the lru list for a buffer we
- * can flush. If we find one, write it (if necessary) and take it
- * off any lists. If we don't find anything we grow the cache anyway.
+ * If the cache is maxxed out, search the lru list for a buffer we
+ * can flush. If we find one, write it if necessary and take it off
+ * any lists. If we don't find anything we grow the cache anyway.
* The cache never shrinks.
*/
- for (bp = mp->lqh.cqh_first;
- bp != (void *)&mp->lqh; bp = bp->q.cqe_next)
- if (!(bp->flags & MPOOL_PINNED)) {
- /* Flush if dirty. */
- if (bp->flags & MPOOL_DIRTY &&
- mpool_write(mp, bp) == RET_ERROR)
+ for (b = mp->lru.cprev; b != (BKT *)&mp->lru; b = b->cprev)
+ if (!(b->flags & MPOOL_PINNED)) {
+ if (b->flags & MPOOL_DIRTY &&
+ mpool_write(mp, b) == RET_ERROR)
return (NULL);
+ rmhash(b);
+ rmchain(b);
#ifdef STATISTICS
++mp->pageflush;
#endif
- /* Remove from the hash and lru queues. */
- head = &mp->hqh[HASHKEY(bp->pgno)];
- CIRCLEQ_REMOVE(head, bp, hq);
- CIRCLEQ_REMOVE(&mp->lqh, bp, q);
#ifdef DEBUG
- { void *spage;
- spage = bp->page;
- memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
- bp->page = spage;
+ {
+ void *spage;
+ spage = b->page;
+ memset(b, 0xff, sizeof(BKT) + mp->pagesize);
+ b->page = spage;
}
#endif
- return (bp);
+ return (b);
}
-new: if ((bp = (BKT *)malloc(sizeof(BKT) + mp->pagesize)) == NULL)
+new: if ((b = (BKT *)malloc(sizeof(BKT) + mp->pagesize)) == NULL)
return (NULL);
#ifdef STATISTICS
++mp->pagealloc;
#endif
-#if defined(DEBUG) || defined(PURIFY)
- memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
+#ifdef DEBUG
+ memset(b, 0xff, sizeof(BKT) + mp->pagesize);
#endif
- bp->page = (char *)bp + sizeof(BKT);
+ b->page = (char *)b + sizeof(BKT);
++mp->curcache;
- return (bp);
+ return (b);
}
/*
- * mpool_write
- * Write a page to disk.
+ * MPOOL_WRITE -- sync a page to disk
+ *
+ * Parameters:
+ * mp: mpool cookie
+ *
+ * Returns:
+ * RET_ERROR, RET_SUCCESS
*/
static int
-mpool_write(mp, bp)
+mpool_write(mp, b)
MPOOL *mp;
- BKT *bp;
+ BKT *b;
{
off_t off;
+ if (mp->pgout)
+ (mp->pgout)(mp->pgcookie, b->pgno, b->page);
+
#ifdef STATISTICS
++mp->pagewrite;
#endif
-
- /* Run through the user's filter. */
- if (mp->pgout)
- (mp->pgout)(mp->pgcookie, bp->pgno, bp->page);
-
- off = mp->pagesize * bp->pgno;
+ off = mp->pagesize * b->pgno;
if (lseek(mp->fd, off, SEEK_SET) != off)
return (RET_ERROR);
- if (write(mp->fd, bp->page, mp->pagesize) != mp->pagesize)
+ if (write(mp->fd, b->page, mp->pagesize) != mp->pagesize)
return (RET_ERROR);
-
- bp->flags &= ~MPOOL_DIRTY;
+ b->flags &= ~MPOOL_DIRTY;
return (RET_SUCCESS);
}
/*
- * mpool_look
- * Lookup a page in the cache.
+ * MPOOL_LOOK -- lookup a page
+ *
+ * Parameters:
+ * mp: mpool cookie
+ * pgno: page number
+ *
+ * Returns:
+ * NULL on failure and a pointer to the BKT on success
*/
static BKT *
mpool_look(mp, pgno)
MPOOL *mp;
pgno_t pgno;
{
- struct _hqh *head;
- BKT *bp;
+ register BKT *b;
+ register BKTHDR *tb;
- head = &mp->hqh[HASHKEY(pgno)];
- for (bp = head->cqh_first; bp != (void *)head; bp = bp->hq.cqe_next)
- if (bp->pgno == pgno) {
+ /* XXX
+ * If find the buffer, put it first on the hash chain so can
+ * find it again quickly.
+ */
+ tb = &mp->hashtable[HASHKEY(pgno)];
+ for (b = tb->hnext; b != (BKT *)tb; b = b->hnext)
+ if (b->pgno == pgno) {
#ifdef STATISTICS
++mp->cachehit;
#endif
- return (bp);
+ return (b);
}
#ifdef STATISTICS
++mp->cachemiss;
@@ -415,14 +455,16 @@ mpool_look(mp, pgno)
#ifdef STATISTICS
/*
- * mpool_stat
- * Print out cache statistics.
+ * MPOOL_STAT -- cache statistics
+ *
+ * Parameters:
+ * mp: mpool cookie
*/
void
mpool_stat(mp)
MPOOL *mp;
{
- BKT *bp;
+ BKT *b;
int cnt;
char *sep;
@@ -436,7 +478,7 @@ mpool_stat(mp)
mp->pagealloc, mp->pageflush);
if (mp->cachehit + mp->cachemiss)
(void)fprintf(stderr,
- "%.0f%% cache hit rate (%lu hits, %lu misses)\n",
+ "%.0f%% cache hit rate (%lu hits, %lu misses)\n",
((double)mp->cachehit / (mp->cachehit + mp->cachemiss))
* 100, mp->cachehit, mp->cachemiss);
(void)fprintf(stderr, "%lu page reads, %lu page writes\n",
@@ -444,20 +486,49 @@ mpool_stat(mp)
sep = "";
cnt = 0;
- for (bp = mp->lqh.cqh_first;
- bp != (void *)&mp->lqh; bp = bp->q.cqe_next) {
- (void)fprintf(stderr, "%s%d", sep, bp->pgno);
- if (bp->flags & MPOOL_DIRTY)
+ for (b = mp->lru.cnext; b != (BKT *)&mp->lru; b = b->cnext) {
+ (void)fprintf(stderr, "%s%d", sep, b->pgno);
+ if (b->flags & MPOOL_DIRTY)
(void)fprintf(stderr, "d");
- if (bp->flags & MPOOL_PINNED)
+ if (b->flags & MPOOL_PINNED)
(void)fprintf(stderr, "P");
if (++cnt == 10) {
sep = "\n";
cnt = 0;
} else
sep = ", ";
-
+
}
(void)fprintf(stderr, "\n");
}
#endif
+
+#ifdef DEBUG
+#if __STDC__
+#include <stdarg.h>
+#else
+#include <varargs.h>
+#endif
+
+static void
+#if __STDC__
+__mpoolerr(const char *fmt, ...)
+#else
+__mpoolerr(fmt, va_alist)
+ char *fmt;
+ va_dcl
+#endif
+{
+ va_list ap;
+#if __STDC__
+ va_start(ap, fmt);
+#else
+ va_start(ap);
+#endif
+ (void)vfprintf(stderr, fmt, ap);
+ va_end(ap);
+ (void)fprintf(stderr, "\n");
+ abort();
+ /* NOTREACHED */
+}
+#endif
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-12 22:49:46 +0000