diff options
Diffstat (limited to 'db2/db/db_dispatch.c')
| -rw-r--r-- | db2/db/db_dispatch.c | 117 |
1 files changed, 70 insertions, 47 deletions
diff --git a/db2/db/db_dispatch.c b/db2/db/db_dispatch.c index 736575adfc..8645948614 100644 --- a/db2/db/db_dispatch.c +++ b/db2/db/db_dispatch.c @@ -1,7 +1,7 @@ /*- * See the file LICENSE for redistribution information. * - * Copyright (c) 1996, 1997 + * Copyright (c) 1996, 1997, 1998 * Sleepycat Software. All rights reserved. */ /* @@ -43,14 +43,13 @@ #include "config.h" #ifndef lint -static const char sccsid[] = "@(#)db_dispatch.c 10.9 (Sleepycat) 1/17/98"; +static const char sccsid[] = "@(#)db_dispatch.c 10.14 (Sleepycat) 5/3/98"; #endif /* not lint */ #ifndef NO_SYSTEM_INCLUDES #include <sys/types.h> #include <errno.h> -#include <fcntl.h> #include <stddef.h> #include <stdlib.h> #include <string.h> @@ -62,6 +61,7 @@ static const char sccsid[] = "@(#)db_dispatch.c 10.9 (Sleepycat) 1/17/98"; #include "db_am.h" #include "common_ext.h" #include "log_auto.h" +#include "txn_auto.h" /* * Data structures to manage the DB dispatch table. The dispatch table @@ -114,7 +114,7 @@ __db_dispatch(logp, db, lsnp, redo, info) * seen it, then we call the appropriate recovery routine * in "abort mode". */ - if (rectype == DB_log_register || + if (rectype == DB_log_register || rectype == DB_txn_ckp || __db_txnlist_find(info, txnid) == DB_NOTFOUND) return ((dispatch_table[rectype])(logp, db, lsnp, TXN_UNDO, info)); @@ -124,7 +124,7 @@ __db_dispatch(logp, db, lsnp, redo, info) * In the forward pass, if we haven't seen the transaction, * do nothing, else recovery it. */ - if (rectype == DB_log_register || + if (rectype == DB_log_register || rectype == DB_txn_ckp || __db_txnlist_find(info, txnid) != DB_NOTFOUND) return ((dispatch_table[rectype])(logp, db, lsnp, TXN_REDO, info)); @@ -188,14 +188,14 @@ int __db_txnlist_init(retp) void *retp; { - __db_txnhead *headp; + DB_TXNHEAD *headp; - if ((headp = (struct __db_txnhead *) - __db_malloc(sizeof(struct __db_txnhead))) == NULL) + if ((headp = (DB_TXNHEAD *)__db_malloc(sizeof(DB_TXNHEAD))) == NULL) return (ENOMEM); LIST_INIT(&headp->head); headp->maxid = 0; + headp->generation = 1; *(void **)retp = headp; return (0); @@ -212,25 +212,26 @@ __db_txnlist_add(listp, txnid) void *listp; u_int32_t txnid; { - __db_txnhead *hp; - __db_txnlist *elp; + DB_TXNHEAD *hp; + DB_TXNLIST *elp; - if ((elp = (__db_txnlist *)__db_malloc(sizeof(__db_txnlist))) == NULL) + if ((elp = (DB_TXNLIST *)__db_malloc(sizeof(DB_TXNLIST))) == NULL) return (ENOMEM); elp->txnid = txnid; - hp = (struct __db_txnhead *)listp; + hp = (DB_TXNHEAD *)listp; LIST_INSERT_HEAD(&hp->head, elp, links); if (txnid > hp->maxid) hp->maxid = txnid; + elp->generation = hp->generation; return (0); } /* * __db_txnlist_find -- - * Checks to see if txnid is in the txnid list, returns 1 if found, - * 0 if not found. + * Checks to see if a txnid with the current generation is in the + * txnid list. * * PUBLIC: int __db_txnlist_find __P((void *, u_int32_t)); */ @@ -239,45 +240,19 @@ __db_txnlist_find(listp, txnid) void *listp; u_int32_t txnid; { - __db_txnhead *hp; - __db_txnlist *p; + DB_TXNHEAD *hp; + DB_TXNLIST *p; - if ((hp = (struct __db_txnhead *)listp) == NULL) + if ((hp = (DB_TXNHEAD *)listp) == NULL) return (DB_NOTFOUND); - if (hp->maxid < txnid) { - hp->maxid = txnid; - return (DB_NOTFOUND); - } - for (p = hp->head.lh_first; p != NULL; p = p->links.le_next) - if (p->txnid == txnid) + if (p->txnid == txnid && hp->generation == p->generation) return (0); return (DB_NOTFOUND); } -#ifdef DEBUG -/* - * __db_txnlist_print -- - * Print out the transaction list. - * - * PUBLIC: void __db_txnlist_print __P((void *)); - */ -void -__db_txnlist_print(listp) - void *listp; -{ - __db_txnhead *hp; - __db_txnlist *p; - - hp = (struct __db_txnhead *)listp; - printf("Maxid: %lu\n", (u_long)hp->maxid); - for (p = hp->head.lh_first; p != NULL; p = p->links.le_next) - printf("TXNID: %lu\n", (u_long)p->txnid); -} -#endif - /* * __db_txnlist_end -- * Discard transaction linked list. @@ -288,13 +263,61 @@ void __db_txnlist_end(listp) void *listp; { - __db_txnhead *hp; - __db_txnlist *p; + DB_TXNHEAD *hp; + DB_TXNLIST *p; - hp = (struct __db_txnhead *)listp; + hp = (DB_TXNHEAD *)listp; while ((p = LIST_FIRST(&hp->head)) != LIST_END(&hp->head)) { LIST_REMOVE(p, links); __db_free(p); } __db_free(listp); } + +/* + * __db_txnlist_gen -- + * Change the current generation number. + * + * PUBLIC: void __db_txnlist_gen __P((void *, int)); + */ +void +__db_txnlist_gen(listp, incr) + void *listp; + int incr; +{ + DB_TXNHEAD *hp; + + /* + * During recovery generation numbers keep track of how many "restart" + * checkpoints we've seen. Restart checkpoints occur whenever we take + * a checkpoint and there are no outstanding transactions. When that + * happens, we can reset transaction IDs back to 1. It always happens + * at recovery and it prevents us from exhausting the transaction IDs + * name space. + */ + hp = (DB_TXNHEAD *)listp; + hp->generation += incr; +} + +#ifdef DEBUG +/* + * __db_txnlist_print -- + * Print out the transaction list. + * + * PUBLIC: void __db_txnlist_print __P((void *)); + */ +void +__db_txnlist_print(listp) + void *listp; +{ + DB_TXNHEAD *hp; + DB_TXNLIST *p; + + hp = (DB_TXNHEAD *)listp; + printf("Maxid: %lu Generation: %lu\n", (u_long)hp->maxid, + (u_long)hp->generation); + for (p = hp->head.lh_first; p != NULL; p = p->links.le_next) + printf("TXNID: %lu(%lu)\n", (u_long)p->txnid, + (u_long)p->generation); +} +#endif |