diff options
Diffstat (limited to 'lib/libc/db/mpool')
| -rw-r--r-- | lib/libc/db/mpool/Makefile.inc | 6 | ||||
| -rw-r--r-- | lib/libc/db/mpool/README | 7 | ||||
| -rw-r--r-- | lib/libc/db/mpool/mpool.c | 463 | ||||
| -rw-r--r-- | lib/libc/db/mpool/mpool.libtp | 746 |
4 files changed, 1222 insertions, 0 deletions
diff --git a/lib/libc/db/mpool/Makefile.inc b/lib/libc/db/mpool/Makefile.inc new file mode 100644 index 0000000..461e62a --- /dev/null +++ b/lib/libc/db/mpool/Makefile.inc @@ -0,0 +1,6 @@ +# from @(#)Makefile.inc 8.1 (Berkeley) 6/4/93 +# $FreeBSD$ + +.PATH: ${.CURDIR}/../libc/db/mpool + +SRCS+= mpool.c diff --git a/lib/libc/db/mpool/README b/lib/libc/db/mpool/README new file mode 100644 index 0000000..0f01fbc --- /dev/null +++ b/lib/libc/db/mpool/README @@ -0,0 +1,7 @@ +# @(#)README 8.1 (Berkeley) 6/4/93 + +These are the current memory pool routines. +They aren't ready for prime time, yet, and +the interface is expected to change. + +--keith diff --git a/lib/libc/db/mpool/mpool.c b/lib/libc/db/mpool/mpool.c new file mode 100644 index 0000000..a61041e --- /dev/null +++ b/lib/libc/db/mpool/mpool.c @@ -0,0 +1,463 @@ +/*- + * Copyright (c) 1990, 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. + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)mpool.c 8.5 (Berkeley) 7/26/94"; +#endif /* LIBC_SCCS and not lint */ + +#include <sys/param.h> +#include <sys/queue.h> +#include <sys/stat.h> + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <db.h> + +#define __MPOOLINTERFACE_PRIVATE +#include <mpool.h> + +static BKT *mpool_bkt __P((MPOOL *)); +static BKT *mpool_look __P((MPOOL *, pgno_t)); +static int mpool_write __P((MPOOL *, BKT *)); + +/* + * mpool_open -- + * Initialize a memory pool. + */ +MPOOL * +mpool_open(key, fd, pagesize, maxcache) + void *key; + int fd; + pgno_t pagesize, maxcache; +{ + struct stat sb; + 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); + if (!S_ISREG(sb.st_mode)) { + errno = ESPIPE; + return (NULL); + } + + /* Allocate and initialize the MPOOL cookie. */ + if ((mp = (MPOOL *)calloc(1, sizeof(MPOOL))) == NULL) + return (NULL); + CIRCLEQ_INIT(&mp->lqh); + for (entry = 0; entry < HASHSIZE; ++entry) + CIRCLEQ_INIT(&mp->hqh[entry]); + mp->maxcache = maxcache; + mp->npages = sb.st_size / pagesize; + mp->pagesize = pagesize; + mp->fd = fd; + return (mp); +} + +/* + * mpool_filter -- + * Initialize input/output filters. + */ +void +mpool_filter(mp, pgin, pgout, pgcookie) + MPOOL *mp; + void (*pgin) __P((void *, pgno_t, void *)); + void (*pgout) __P((void *, pgno_t, void *)); + void *pgcookie; +{ + mp->pgin = pgin; + mp->pgout = pgout; + mp->pgcookie = pgcookie; +} + +/* + * mpool_new -- + * Get a new page of memory. + */ +void * +mpool_new(mp, pgnoaddr) + MPOOL *mp; + pgno_t *pgnoaddr; +{ + struct _hqh *head; + BKT *bp; + + 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. + */ + if ((bp = 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); +} + +/* + * mpool_get + * Get a page. + */ +void * +mpool_get(mp, pgno, flags) + MPOOL *mp; + pgno_t pgno; + u_int flags; /* XXX not used? */ +{ + struct _hqh *head; + BKT *bp; + off_t off; + int nr; + + /* Check for attempt to retrieve a non-existent page. */ + if (pgno >= mp->npages) { + errno = EINVAL; + return (NULL); + } + +#ifdef STATISTICS + ++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(); + } +#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); + } + + /* Get a page from the cache. */ + if ((bp = mpool_bkt(mp)) == NULL) + return (NULL); + + /* Read in the contents. */ +#ifdef STATISTICS + ++mp->pageread; +#endif + 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 >= 0) + errno = EFTYPE; + return (NULL); + } + + /* 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); +} + +/* + * mpool_put + * Return a page. + */ +int +mpool_put(mp, page, flags) + MPOOL *mp; + void *page; + u_int flags; +{ + BKT *bp; + +#ifdef STATISTICS + ++mp->pageput; +#endif + bp = (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(); + } +#endif + bp->flags &= ~MPOOL_PINNED; + bp->flags |= flags & MPOOL_DIRTY; + return (RET_SUCCESS); +} + +/* + * mpool_close + * Close the buffer pool. + */ +int +mpool_close(mp) + MPOOL *mp; +{ + BKT *bp; + + /* 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); + } + + /* Free the MPOOL cookie. */ + free(mp); + return (RET_SUCCESS); +} + +/* + * mpool_sync + * Sync the pool to disk. + */ +int +mpool_sync(mp) + MPOOL *mp; +{ + BKT *bp; + + /* 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) + 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). + */ +static BKT * +mpool_bkt(mp) + MPOOL *mp; +{ + struct _hqh *head; + BKT *bp; + + /* 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. + * 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) + return (NULL); +#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; + } +#endif + return (bp); + } + +new: if ((bp = (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); +#endif + bp->page = (char *)bp + sizeof(BKT); + ++mp->curcache; + return (bp); +} + +/* + * mpool_write + * Write a page to disk. + */ +static int +mpool_write(mp, bp) + MPOOL *mp; + BKT *bp; +{ + off_t off; + +#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; + if (lseek(mp->fd, off, SEEK_SET) != off) + return (RET_ERROR); + if (write(mp->fd, bp->page, mp->pagesize) != mp->pagesize) + return (RET_ERROR); + + bp->flags &= ~MPOOL_DIRTY; + return (RET_SUCCESS); +} + +/* + * mpool_look + * Lookup a page in the cache. + */ +static BKT * +mpool_look(mp, pgno) + MPOOL *mp; + pgno_t pgno; +{ + struct _hqh *head; + BKT *bp; + + head = &mp->hqh[HASHKEY(pgno)]; + for (bp = head->cqh_first; bp != (void *)head; bp = bp->hq.cqe_next) + if (bp->pgno == pgno) { +#ifdef STATISTICS + ++mp->cachehit; +#endif + return (bp); + } +#ifdef STATISTICS + ++mp->cachemiss; +#endif + return (NULL); +} + +#ifdef STATISTICS +/* + * mpool_stat + * Print out cache statistics. + */ +void +mpool_stat(mp) + MPOOL *mp; +{ + BKT *bp; + int cnt; + char *sep; + + (void)fprintf(stderr, "%lu pages in the file\n", mp->npages); + (void)fprintf(stderr, + "page size %lu, cacheing %lu pages of %lu page max cache\n", + mp->pagesize, mp->curcache, mp->maxcache); + (void)fprintf(stderr, "%lu page puts, %lu page gets, %lu page new\n", + mp->pageput, mp->pageget, mp->pagenew); + (void)fprintf(stderr, "%lu page allocs, %lu page flushes\n", + mp->pagealloc, mp->pageflush); + if (mp->cachehit + mp->cachemiss) + (void)fprintf(stderr, + "%.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", + mp->pageread, mp->pagewrite); + + 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) + (void)fprintf(stderr, "d"); + if (bp->flags & MPOOL_PINNED) + (void)fprintf(stderr, "P"); + if (++cnt == 10) { + sep = "\n"; + cnt = 0; + } else + sep = ", "; + + } + (void)fprintf(stderr, "\n"); +} +#endif diff --git a/lib/libc/db/mpool/mpool.libtp b/lib/libc/db/mpool/mpool.libtp new file mode 100644 index 0000000..bcd827d --- /dev/null +++ b/lib/libc/db/mpool/mpool.libtp @@ -0,0 +1,746 @@ +/****************************************************************************** + +VERSION $FreeBSD$ +PACKAGE: User Level Shared Memory Manager + +DESCRIPTION: + This package provides a buffer pool interface implemented as + a collection of file pages mapped into shared memory. + + Based on Mark's buffer manager + +ROUTINES: + External + buf_alloc + buf_flags + buf_get + buf_init + buf_last + buf_open + buf_pin + buf_sync + buf_unpin + Internal + bf_assign_buf + bf_fid_to_fd + bf_newbuf + bf_put_page + + +******************************************************************************/ +#include <sys/types.h> +#include <assert.h> +#include <sys/file.h> +#include <sys/stat.h> +#include <stdio.h> +#include <errno.h> +#include "list.h" +#include "user.h" +#include "txn_sys.h" +#include "buf.h" +#include "semkeys.h" +#include "error.h" + +/* + we need to translate between some type of file id that the user + process passes and a file descriptor. For now, it's a nop. +*/ +#define GET_MASTER get_sem ( buf_spinlock ) +#define RELEASE_MASTER release_sem ( buf_spinlock ) + +#define LRUID *buf_lru +#define LRUP (bufhdr_table+*buf_lru) +#define MRU bufhdr_table[*buf_lru].lru.prev + +/* Global indicator that you have started reusing buffers */ +int do_statistics = 0; +/* + Process Statics (pointers into shared memory) +*/ +static BUF_T *buf_table = 0; +static BUFHDR_T *bufhdr_table; +static int *buf_hash_table; +static int *buf_lru; /* LRU is the free list */ +static int buf_spinlock; +static FINFO_T *buf_fids; +static int *buf_sp; /* Pointer to string free space */ +static char *buf_strings; + +/* Process Local FID->FD table */ +static int fds[NUM_FILE_ENTRIES]; + +/* Static routines */ +static BUFHDR_T *bf_assign_buf(); +static int bf_fid_to_fd(); +static BUFHDR_T *bf_newbuf(); +static int bf_put_page(); + +/* + Return 0 on success + 1 on failure +*/ +extern int +buf_init ( ) +{ + ADDR_T buf_region; + BUFHDR_T *bhp; + int i; + int ref_count; + int *spinlockp; + + /* + Initialize Process local structures + */ + for ( i = 0; i < NUM_FILE_ENTRIES; i++ ) { + fds[i] = -1; + } + + buf_region = attach_region ( BUF_REGION_NAME, BUF_REGION_NUM, + BUF_REGION_SIZE, &ref_count ); + if ( !buf_region ) { + return (1); + } + error_log3 ( "Buf Region: ADDR: %d ID: %d SIZE: %d\n", buf_region, + BUF_REGION_NUM, BUF_REGION_SIZE ); + + buf_table = (BUF_T *)buf_region; + bufhdr_table = (BUFHDR_T *)(buf_table + NUM_BUFS); + buf_hash_table = (int *)(bufhdr_table + NUM_BUFS); + buf_lru = buf_hash_table + NUMTABLE_ENTRIES; + spinlockp = buf_lru + 1; + buf_fids = (FINFO_T *)(spinlockp+1); + buf_sp = (int *)(buf_fids + NUM_FILE_ENTRIES); + buf_strings = (char *)(buf_sp + 1); + + /* Create locking spinlock (gets creating holding the lock) */ + buf_spinlock = create_sem ( BUF_SPIN_NAME, BUF_SPIN_NUM, ref_count <= 1 ); + if ( buf_spinlock < 0 ) { + return(1); + } + if ( ref_count <= 1 ) { + *spinlockp = buf_spinlock; + + /* Now initialize the buffer manager */ + + /* 1. Free list */ + *buf_lru = 0; + + /* 2. Buffer headers */ + for ( i = 0, bhp = bufhdr_table; i < NUM_BUFS; bhp++, i++ ) { + bhp->lru.next = i+1; + bhp->lru.prev = i-1; + bhp->flags = 0; /* All Flags off */ + bhp->refcount = 0; + bhp->wait_proc = -1; /* No sleepers */ + LISTPE_INIT ( hash, bhp, i ); /* Hash chains */ + } + bufhdr_table[0].lru.prev = NUM_BUFS-1; + bufhdr_table[NUM_BUFS-1].lru.next = 0; + + /* 3. Hash Table */ + for ( i = 0; i < NUMTABLE_ENTRIES; i++ ) { + buf_hash_table[i] = NUM_BUFS; + } + + /* 4. File ID Table */ + for ( i = 0; i < NUM_FILE_ENTRIES; i++ ) { + buf_fids[i].offset = -1; + buf_fids[i].npages = -1; + buf_fids[i].refcount = 0; + } + + /* 5. Free String Pointer */ + *buf_sp = (FILE_NAME_LEN*NUM_FILE_ENTRIES); + if (RELEASE_MASTER) { + return(1); + } + error_log0 ( "Initialized buffer region\n" ); + } + return (0); +} + +extern void +buf_exit() +{ + int ref; + int i; + + /* Flush Buffer Pool on Exit */ + for ( i = 0; i < NUM_FILE_ENTRIES; i++ ) { + if ( fds[i] != -1 ) { + close ( fds[i] ); + } + } + if ( buf_table ) { + detach_region ( buf_table, BUF_REGION_NUM, BUF_REGION_SIZE, &ref ); + } + return; +} + +/* + We need an empty buffer. Find the LRU unpinned NON-Dirty page. +*/ +static BUFHDR_T * +bf_newbuf() +{ + int fd; + int lruid; + int nbytes; + int ndx; + BUFHDR_T *bhp; + + lruid = LRUID; + for ( bhp = LRUP; + bhp->flags & (BUF_PINNED|BUF_IO_IN_PROGRESS); + bhp = LISTP_NEXTP (bufhdr_table, lru, bhp ) ) { + + if ( bhp->lru.next == lruid ) { + /* OUT OF BUFFERS */ + error_log1 ( "All buffers are pinned. %s\n", + "Unable to grant buffer request" ); + return(NULL); + } + } + /* BHP can be used */ + if ( bhp->flags & BUF_DIRTY ) { + do_statistics = 1; + /* + MIS Check for log flushed appropriately + */ + fd = bf_fid_to_fd(bhp->id.file_id); + if ( fd == -1 ) { + error_log1 ("Invalid fid %d\n", bhp->id.file_id); + return(NULL); + } + if ( bf_put_page(fd, bhp) < 0 ) { + return(NULL); + } + } + /* Update Hash Pointers */ + ndx = BUF_HASH ( bhp->id.file_id, bhp->id.obj_id ); + LISTP_REMOVE(bufhdr_table, hash, bhp); + if ( buf_hash_table[ndx] == (bhp-bufhdr_table) ) { + if ( bhp->hash.next != (bhp-bufhdr_table) ) { + buf_hash_table[ndx] = bhp->hash.next; + } else { + buf_hash_table[ndx] = NUM_BUFS; + } + } + INIT_BUF(bhp); + + return(bhp); +} +/* + buf_alloc + + Add a page to a file and return a buffer for it. + +*/ +ADDR_T +buf_alloc ( fid, new_pageno ) +int fid; +int *new_pageno; +{ + BUFHDR_T *bhp; + int fd; + int len; + int ndx; + OBJ_T fobj; + + if (GET_MASTER) { + return(NULL); + } + if ( buf_fids[fid].npages == -1 ) { + /* initialize npages field */ + fd = bf_fid_to_fd ( fid ); + } + assert (fid < NUM_FILE_ENTRIES); + + *new_pageno = buf_fids[fid].npages; + if ( *new_pageno == -1 ) { + RELEASE_MASTER; + return ( NULL ); + } + buf_fids[fid].npages++; + ndx = BUF_HASH ( fid, *new_pageno ); + fobj.file_id = fid; + fobj.obj_id = *new_pageno; + bhp = bf_assign_buf ( ndx, &fobj, BF_PIN|BF_DIRTY|BF_EMPTY, &len ); + if ( RELEASE_MASTER ) { + /* Memory leak */ + return(NULL); + } + if ( bhp ) { + return ((ADDR_T)(buf_table+(bhp-bufhdr_table))); + } else { + return ( NULL ); + } +} + + +/* + Buffer Flags + BF_DIRTY Mark page as dirty + BF_EMPTY Don't initialize page, just get buffer + BF_PIN Retrieve with pin + +MIS +Might want to add a flag that sets an LSN for this buffer is the +DIRTY flag is set + +Eventually, you may want a flag that indicates the I/O and lock +request should be shipped off together, but not for now. +*/ +extern ADDR_T +buf_get ( file_id, page_id, flags, len ) +int file_id; +int page_id; +u_long flags; +int *len; /* Number of bytes read into buffer */ +{ + BUFHDR_T *bhp; + int bufid; + int fd; + int ndx; + int next_bufid; + int stat; + OBJ_T fobj; + + ndx = BUF_HASH ( file_id, page_id ); + fobj.file_id = (long) file_id; + fobj.obj_id = (long) page_id; + if ( GET_MASTER ) { + return(NULL); + } + /* + This could be a for loop, but we lose speed + by making all the cases general purpose so we + optimize for the no-collision case. + */ + bufid = buf_hash_table[ndx]; + if ( bufid < NUM_BUFS ) { + for ( bhp = bufhdr_table+bufid; + !OBJ_EQ (bhp->id, fobj) || !(bhp->flags & BUF_VALID); + bhp = LISTP_NEXTP ( bufhdr_table, hash, bhp ) ) { + + if ( bhp->hash.next == bufid ) { + goto not_found; + } + } +/* found */ + if ( flags & BF_PIN ) { + bhp->flags |= BUF_PINNED; + bhp->refcount++; +#ifdef PIN_DEBUG + fprintf(stderr, "buf_get: %X PINNED (%d)\n", + buf_table + (bhp-bufhdr_table), bhp->refcount); +#endif + } + if ( flags & BF_DIRTY ) { + bhp->flags |= BUF_DIRTY; + } + + while ( bhp->flags & BUF_IO_IN_PROGRESS ) { + /* MIS -- eventually err check here */ +#ifdef DEBUG + printf("About to sleep on %d (me: %d\n)\n", bhp->wait_proc, + my_txnp - txn_table); +#endif +#ifdef WAIT_STATS + buf_waits++; +#endif + stat = proc_sleep_on ( &(bhp->wait_proc), buf_spinlock ); + if ( stat ) { + /* Memory leak */ + return(NULL); + } + if (!( bhp->flags & BUF_IO_IN_PROGRESS) && + (!OBJ_EQ (bhp->id, fobj) || !(bhp->flags & BUF_VALID))) { + if (RELEASE_MASTER) + return(NULL); + return(buf_get ( file_id, page_id, flags, len )); + } + } + MAKE_MRU( bhp ); + *len = BUFSIZE; + } else { +not_found: + /* If you get here, the page isn't in the hash table */ + bhp = bf_assign_buf ( ndx, &fobj, flags, len ); + } + /* Common code between found and not found */ + + if ( bhp && bhp->flags & BUF_NEWPAGE ) { + *len = 0; + } + if (RELEASE_MASTER){ + /* Memory leak */ + return(NULL); + } + if ( bhp ) { + return ((ADDR_T)(buf_table+(bhp-bufhdr_table))); + } else { + return ( NULL ); + } +} + +/* + MIS - do I want to add file links to buffer pool? +*/ +extern int +buf_sync ( fid, close ) +int fid; +int close; /* should we dec refcount and possibly + invalidate all the buffers */ +{ + int i; + int fd; + int invalidate; + BUFHDR_T *bhp; + + if ( (fd = bf_fid_to_fd ( fid )) < 0 ) { + return(1); + } + if (GET_MASTER) { + return(1); + } + invalidate = (buf_fids[fid].refcount == 1 && close); + if ( invalidate ) + for ( bhp = bufhdr_table, i = 0; i < NUM_BUFS; bhp++, i++ ) { + if (bhp->id.file_id == fid) { + if ((bhp->flags & BF_DIRTY) && (bf_put_page( fd, bhp ) < 0)) { + return(1); + } + bhp->id.file_id = -1; + } + } + if (invalidate || close) + buf_fids[fid].refcount--; + + if (RELEASE_MASTER) { + return(1); + } + return(0); + + +} + +extern int +buf_flags ( addr, set_flags, unset_flags ) +ADDR_T addr; +u_long set_flags; +u_long unset_flags; +{ + int bufid; + BUFHDR_T *bhp; + +#ifdef PIN_DEBUG + fprintf(stderr, "buf_flags: %X setting %s%s%s%s%s releasing %s%s%s%s%s\n", + addr, + set_flags&BUF_DIRTY ? "DIRTY " : "", + set_flags&BUF_VALID ? "VALID " : "", + set_flags&BUF_PINNED ? "PINNED " : "", + set_flags&BUF_IO_ERROR ? "IO_ERROR " : "", + set_flags&BUF_IO_IN_PROGRESS ? "IO_IN_PROG " : "", + set_flags&BUF_NEWPAGE ? "NEWPAGE " : "", + unset_flags&BUF_DIRTY ? "DIRTY " : "", + unset_flags&BUF_VALID ? "VALID " : "", + unset_flags&BUF_PINNED ? "PINNED " : "", + unset_flags&BUF_IO_ERROR ? "IO_ERROR " : "", + unset_flags&BUF_IO_IN_PROGRESS ? "IO_IN_PROG " : "", + unset_flags&BUF_NEWPAGE ? "NEWPAGE " : "" ); +#endif + if (!ADDR_OK(addr)) { + error_log1 ( "buf_pin: Invalid Buffer Address %x\n", addr ); + return(1); + } + bufid = ((BUF_T *)addr) - buf_table; + assert ( bufid < NUM_BUFS); + bhp = &bufhdr_table[bufid]; + if (GET_MASTER) { + return(1); + } + bhp->flags |= set_flags; + if ( set_flags & BUF_PINNED ) { + bhp->refcount++; + } + if ( set_flags & BUF_DIRTY ) { + unset_flags |= BUF_NEWPAGE; + } + + if ( unset_flags & BUF_PINNED ) { + bhp->refcount--; + if ( bhp->refcount ) { + /* Turn off pin bit so it doesn't get unset */ + unset_flags &= ~BUF_PINNED; + } + } + bhp->flags &= ~unset_flags; + MAKE_MRU(bhp); + if (RELEASE_MASTER) { + return(1); + } + return(0); +} + +/* + Take a string name and produce an fid. + + returns -1 on error + + MIS -- this is a potential problem -- you keep actual names + here -- what if people run from different directories? +*/ +extern int +buf_name_lookup ( fname ) +char *fname; +{ + int i; + int fid; + int ndx; + + fid = -1; + if (GET_MASTER) { + return(-1); + } + for ( i = 0; i < NUM_FILE_ENTRIES; i++ ) { + if ( buf_fids[i].offset == -1 ) { + fid = i; + } else { + if (!strcmp (fname, buf_strings+buf_fids[i].offset)) { + if (RELEASE_MASTER) { + return(-1); + } + buf_fids[i].refcount++; + return(i); + } + } + } + if ( fid == -1 ) { + error_log0 ( "No more file ID's\n" ); + } else { + ndx = *buf_sp - strlen(fname) - 1; + if ( ndx < 0 ) { + error_log0 ( "Out of string space\n" ); + fid = -1; + } else { + *buf_sp = ndx; + strcpy ( buf_strings+ndx, fname ); + buf_fids[fid].offset = ndx; + } + buf_fids[fid].refcount = 1; + } + if (RELEASE_MASTER) { + return(-1); + } + return(fid); +} + +static int +bf_fid_to_fd ( fid ) +int fid; +{ + struct stat sbuf; + + assert ( (fid < NUM_FILE_ENTRIES) && (buf_fids[fid].offset != -1) ); + if ( fds[fid] != -1 ) { + return(fds[fid]); + + } + fds[fid] = open ( buf_strings+buf_fids[fid].offset, O_RDWR|O_CREAT, + 0666 ); + if ( fds[fid] < 0 ) { + error_log3 ( "Error Opening File %s FID: %d FD: %d. Errno = %d\n", + buf_strings+buf_fids[fid].offset, fid, fds[fid], + errno ); + return(-1); + } + error_log3 ( "Opening File %s FID: %d FD: %d\n", + buf_strings+buf_fids[fid].offset, fid, fds[fid] ); + if ( buf_fids[fid].npages == -1 ) { + /* Initialize the npages field */ + if ( fstat ( fds[fid], &sbuf ) ) { + error_log3 ( "Error Fstating %s FID: %d. Errno = %d\n", + buf_strings+buf_fids[fid].offset, fid, errno ); + } else { + buf_fids[fid].npages = ( sbuf.st_size / BUFSIZE ); + } + } + + return ( fds[fid] ); +} + +static int +bf_put_page ( fd, bhp ) +int fd; +BUFHDR_T *bhp; +{ + int nbytes; + + assert ( (bhp-bufhdr_table) < NUM_BUFS ); + if ( lseek ( fd, bhp->id.obj_id << BUFSHIFT, L_SET ) < 0 ) { + return(-1); + } + bhp->flags |= BUF_IO_IN_PROGRESS; + if (RELEASE_MASTER) { + return(-1); + } + nbytes = write(fd, buf_table[bhp-bufhdr_table], BUFSIZE); + if (GET_MASTER) { + return(-2); + } + if ( nbytes < 0 ) { + error_log1 ("Write failed with error code %d\n", errno); + return(-1); + } else if ( nbytes != BUFSIZE ) { + error_log1 ("Short write: %d bytes of %d\n", nbytes, BUFSIZE ); + } + bhp->flags &= ~(BUF_DIRTY|BUF_IO_IN_PROGRESS); + return (0); +} + +static BUFHDR_T * +bf_assign_buf ( ndx, obj, flags, len ) +int ndx; +OBJ_T *obj; +u_long flags; +int *len; /* Number of bytes read */ +{ + BUFHDR_T *bhp; + int fd; + + assert ( obj->file_id < NUM_FILE_ENTRIES ); + bhp = bf_newbuf(); + if ( !bhp ) { + return(NULL); + } + OBJ_ASSIGN ( (*obj), bhp->id ); + if ( buf_hash_table[ndx] >= NUM_BUFS ) { + buf_hash_table[ndx] = bhp-bufhdr_table; + } else { + LISTPE_INSERT ( bufhdr_table, hash, bhp, buf_hash_table[ndx] ); + } + + bhp->flags |= BUF_VALID; + if ( flags & BF_PIN ) { + bhp->flags |= BUF_PINNED; + bhp->refcount++; +#ifdef PIN_DEBUG + fprintf(stderr, "bf_assign_buf: %X PINNED (%d)\n", + buf_table + (bhp-bufhdr_table), bhp->refcount); +#endif + } + fd = bf_fid_to_fd(obj->file_id); + if ( fd == -1 ) { + error_log1 ("Invalid fid %d\n", obj->file_id); + bhp->flags |= ~BUF_IO_ERROR; + return(NULL); + } + if ( obj->obj_id >= buf_fids[obj->file_id].npages) { + buf_fids[obj->file_id].npages = obj->obj_id+1; + *len = 0; + } else if ( flags & BF_EMPTY ) { + *len = 0; + } else { + bhp->flags |= BUF_IO_IN_PROGRESS; + if (RELEASE_MASTER) { + return(NULL); + } + if ( lseek ( fd, obj->obj_id << BUFSHIFT, L_SET ) < -1 ) { + error_log2 ("Unable to perform seek on file: %d to page %d", + obj->file_id, obj->obj_id ); + bhp->flags &= ~BUF_IO_IN_PROGRESS; + bhp->flags |= ~BUF_IO_ERROR; + return(NULL); + } + *len = read(fd, buf_table[bhp-bufhdr_table], BUFSIZE); + if ( *len < 0 ) { + error_log2 ("Unable to perform read on file: %d to page %d", + obj->file_id, obj->obj_id ); + bhp->flags &= ~BUF_IO_IN_PROGRESS; + bhp->flags |= ~BUF_IO_ERROR; + return(NULL); + } + if (GET_MASTER) { + return(NULL); + } + bhp->flags &= ~BUF_IO_IN_PROGRESS; + if ( bhp->wait_proc != -1 ) { + /* wake up waiter and anyone waiting on it */ +#ifdef DEBUG + printf("Waking transaction %d due to completed I/O\n", + bhp->wait_proc); +#endif + proc_wake_id ( bhp->wait_proc ); + bhp->wait_proc = -1; + } + MAKE_MRU(bhp); + } + + if ( flags & BF_DIRTY ) { + bhp->flags |= BUF_DIRTY; + } else if ( *len < BUFSIZE ) { + bhp->flags |= BUF_NEWPAGE; + } + return ( bhp ); +} + +int +buf_last ( fid ) +int fid; +{ + int val; + + if (GET_MASTER) { + return(-1); + } + assert ( fid < NUM_FILE_ENTRIES ); + if ( buf_fids[fid].npages == -1 ) { + /* initialize npages field */ + (void) bf_fid_to_fd ( fid ); + } + val = buf_fids[fid].npages; + if ( val ) { + val--; /* Convert to page number */ + } + if (RELEASE_MASTER) { + return(-1); + } + return(val); +} + +#ifdef DEBUG +extern void +buf_dump ( id, all ) +int id; +int all; +{ + int i; + BUFHDR_T *bhp; + + printf ( "LRU + %d\n", *buf_lru ); + if ( all ) { + printf("ID\tFID\tPID\tLNEXT\tLPREV\tHNEXT\tHPREV\tSLEEP\tFLAG\tREFS\n"); + for ( bhp = bufhdr_table, i = 0; i < NUM_BUFS; bhp++, i++ ) { + printf ( "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%x\t%d\n", i, + bhp->id.file_id, bhp->id.obj_id, + bhp->lru.next, bhp->lru.prev, + bhp->hash.next, bhp->hash.prev, + bhp->wait_proc, bhp->flags, bhp->refcount ); + } + } else { + if ( id >= NUM_BUFS ) { + printf ( "Buffer ID (%d) too high\n", id ); + return; + } + bhp = bufhdr_table+id; + printf ( "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\t%x\t%d\n", i, + bhp->id.file_id, bhp->id.obj_id, + bhp->lru.next, bhp->lru.prev, + bhp->hash.next, bhp->hash.prev, + bhp->wait_proc, bhp->flags, bhp->refcount ); + } + return; +} +#endif + |
