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-rw-r--r--db2/txn/txn.c349
1 files changed, 175 insertions, 174 deletions
diff --git a/db2/txn/txn.c b/db2/txn/txn.c
index 2a2e3da97b..4f3ffd8ed2 100644
--- a/db2/txn/txn.c
+++ b/db2/txn/txn.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.
*/
/*
@@ -43,27 +43,20 @@
#include "config.h"
#ifndef lint
-static const char sccsid[] = "@(#)txn.c 10.39 (Sleepycat) 1/8/98";
+static const char sccsid[] = "@(#)txn.c 10.58 (Sleepycat) 5/31/98";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
#include <errno.h>
-#include <fcntl.h>
-#include <stddef.h>
-#include <stdio.h>
-#include <stdlib.h>
#include <string.h>
#include <time.h>
-#include <unistd.h>
#endif
-#include "shqueue.h"
#include "db_int.h"
+#include "shqueue.h"
#include "db_page.h"
#include "db_shash.h"
#include "txn.h"
@@ -74,9 +67,9 @@ static const char sccsid[] = "@(#)txn.c 10.39 (Sleepycat) 1/8/98";
#include "common_ext.h"
static int __txn_check_running __P((const DB_TXN *));
-static int __txn_create __P((DB_ENV *, const char *, u_int));
static int __txn_end __P((DB_TXN *, int));
static int __txn_grow_region __P((DB_TXNMGR *));
+static int __txn_init __P((DB_TXNREGION *));
static int __txn_undo __P((DB_TXN *));
static int __txn_validate_region __P((DB_TXNMGR *));
@@ -85,30 +78,20 @@ static int __txn_validate_region __P((DB_TXNMGR *));
* It assumes that a lock manager and log manager that conform to the db_log(3)
* and db_lock(3) interfaces exist.
*
- * Create and initialize a transaction region in shared memory.
+ * Initialize a transaction region in shared memory.
* Return 0 on success, errno on failure.
*/
static int
-__txn_create(dbenv, path, mode)
- DB_ENV *dbenv;
- const char *path;
- u_int mode;
-{
+__txn_init(txn_region)
DB_TXNREGION *txn_region;
+{
time_t now;
- int fd, maxtxns, ret;
- maxtxns = dbenv->tx_max != 0 ? dbenv->tx_max : 1000;
(void)time(&now);
- /* Region may have existed. If it didn't, the open will fail. */
- if ((ret = __db_rcreate(dbenv, DB_APP_NONE, path, DEFAULT_TXN_FILE,
- mode, TXN_REGION_SIZE(maxtxns), 0, &fd, &txn_region)) != 0)
- return (ret);
-
+ /* maxtxns is already initialized. */
txn_region->magic = DB_TXNMAGIC;
txn_region->version = DB_TXNVERSION;
- txn_region->maxtxns = maxtxns;
txn_region->last_txnid = TXN_MINIMUM;
/* XXX If we ever do more types of locking and logging, this changes. */
txn_region->logtype = 0;
@@ -118,33 +101,22 @@ __txn_create(dbenv, path, mode)
ZERO_LSN(txn_region->pending_ckp);
SH_TAILQ_INIT(&txn_region->active_txn);
__db_shalloc_init((void *)&txn_region[1],
- TXN_REGION_SIZE(maxtxns) - sizeof(DB_TXNREGION));
-
- /* Unlock the region. */
- (void)__db_mutex_unlock(&txn_region->hdr.lock, fd);
+ TXN_REGION_SIZE(txn_region->maxtxns) - sizeof(DB_TXNREGION));
- /* Now unmap and close the region. */
- if ((ret = __db_rclose(dbenv, fd, txn_region)) != 0) {
- (void)txn_unlink(path, 1 /* force */, dbenv);
- return (ret);
- }
return (0);
}
int
txn_open(path, flags, mode, dbenv, mgrpp)
const char *path;
- int flags, mode;
+ u_int32_t flags;
+ int mode;
DB_ENV *dbenv;
DB_TXNMGR **mgrpp;
{
DB_TXNMGR *tmgrp;
- DB_TXNREGION *txn_regionp;
- int fd, ret, retry_cnt;
-
- tmgrp = NULL;
- txn_regionp = NULL;
- fd = -1;
+ u_int32_t maxtxns;
+ int ret;
/* Validate arguments. */
if (dbenv == NULL)
@@ -157,52 +129,57 @@ txn_open(path, flags, mode, dbenv, mgrpp)
if ((ret = __db_fchk(dbenv, "txn_open", flags, OKFLAGS)) != 0)
return (ret);
- retry_cnt = 0;
-retry: if (LF_ISSET(DB_CREATE) && (ret = __txn_create(dbenv, path, mode)) != 0)
- if (ret == EAGAIN && ++retry_cnt < 0) {
- (void)__db_sleep(1, 0);
- goto retry;
- } else /* We did not really create the region */
- flags &= ~DB_CREATE;
-
- retry_cnt = 0;
-retry1: if ((ret = __db_ropen(dbenv, DB_APP_NONE, path, DEFAULT_TXN_FILE,
- flags & ~(DB_CREATE | DB_THREAD | DB_TXN_NOSYNC),
- &fd, &txn_regionp)) != 0) {
- if (ret == EAGAIN && ++retry_cnt < 3) {
- (void)__db_sleep(1, 0);
- goto retry1;
- }
- goto out;
- }
-
-
- /* Check if valid region. */
- if (txn_regionp->magic != DB_TXNMAGIC) {
- __db_err(dbenv, "txn_open: Bad magic number");
- ret = EINVAL;
- goto out;
- }
+ maxtxns = dbenv->tx_max != 0 ? dbenv->tx_max : 20;
/* Now, create the transaction manager structure and set its fields. */
- if ((tmgrp = (DB_TXNMGR *)__db_malloc(sizeof(DB_TXNMGR))) == NULL) {
+ if ((tmgrp = (DB_TXNMGR *)__db_calloc(1, sizeof(DB_TXNMGR))) == NULL) {
__db_err(dbenv, "txn_open: %s", strerror(ENOMEM));
- ret = ENOMEM;
- goto out;
+ return (ENOMEM);
}
+ /* Initialize the transaction manager structure. */
+ tmgrp->mutexp = NULL;
tmgrp->dbenv = dbenv;
tmgrp->recover =
dbenv->tx_recover == NULL ? __db_dispatch : dbenv->tx_recover;
- tmgrp->region = txn_regionp;
- tmgrp->reg_size = txn_regionp->hdr.size;
- tmgrp->fd = fd;
tmgrp->flags = LF_ISSET(DB_TXN_NOSYNC | DB_THREAD);
- tmgrp->mem = &txn_regionp[1];
- tmgrp->mutexp = NULL;
TAILQ_INIT(&tmgrp->txn_chain);
+
+ /* Join/create the txn region. */
+ tmgrp->reginfo.dbenv = dbenv;
+ tmgrp->reginfo.appname = DB_APP_NONE;
+ if (path == NULL)
+ tmgrp->reginfo.path = NULL;
+ else
+ if ((tmgrp->reginfo.path = (char *)__db_strdup(path)) == NULL)
+ goto err;
+ tmgrp->reginfo.file = DEFAULT_TXN_FILE;
+ tmgrp->reginfo.mode = mode;
+ tmgrp->reginfo.size = TXN_REGION_SIZE(maxtxns);
+ tmgrp->reginfo.dbflags = flags;
+ tmgrp->reginfo.addr = NULL;
+ tmgrp->reginfo.fd = -1;
+ tmgrp->reginfo.flags = dbenv->tx_max == 0 ? REGION_SIZEDEF : 0;
+ if ((ret = __db_rattach(&tmgrp->reginfo)) != 0)
+ goto err;
+
+ /* Fill in region-related fields. */
+ tmgrp->region = tmgrp->reginfo.addr;
+ tmgrp->mem = &tmgrp->region[1];
+
+ if (F_ISSET(&tmgrp->reginfo, REGION_CREATED)) {
+ tmgrp->region->maxtxns = maxtxns;
+ if ((ret = __txn_init(tmgrp->region)) != 0)
+ goto err;
+
+ } else if (tmgrp->region->magic != DB_TXNMAGIC) {
+ /* Check if valid region. */
+ __db_err(dbenv, "txn_open: Bad magic number");
+ ret = EINVAL;
+ goto err;
+ }
+
if (LF_ISSET(DB_THREAD)) {
- LOCK_TXNREGION(tmgrp);
if ((ret = __db_shalloc(tmgrp->mem, sizeof(db_mutex_t),
MUTEX_ALIGNMENT, &tmgrp->mutexp)) == 0)
/*
@@ -211,25 +188,27 @@ retry1: if ((ret = __db_ropen(dbenv, DB_APP_NONE, path, DEFAULT_TXN_FILE,
* to be ignored. We put 0 here as a valid placeholder.
*/
__db_mutex_init(tmgrp->mutexp, 0);
- UNLOCK_TXNREGION(tmgrp);
if (ret != 0)
- goto out;
+ goto err;
}
+
+ UNLOCK_TXNREGION(tmgrp);
*mgrpp = tmgrp;
return (0);
-out: if (txn_regionp != NULL)
- (void)__db_rclose(dbenv, fd, txn_regionp);
- if (flags & DB_CREATE)
- (void)txn_unlink(path, 1, dbenv);
- if (tmgrp != NULL) {
- if (tmgrp->mutexp != NULL) {
- LOCK_TXNREGION(tmgrp);
+err: if (tmgrp->reginfo.addr != NULL) {
+ if (tmgrp->mutexp != NULL)
__db_shalloc_free(tmgrp->mem, tmgrp->mutexp);
- UNLOCK_TXNREGION(tmgrp);
- }
- __db_free(tmgrp);
+
+ UNLOCK_TXNREGION(tmgrp);
+ (void)__db_rdetach(&tmgrp->reginfo);
+ if (F_ISSET(&tmgrp->reginfo, REGION_CREATED))
+ (void)txn_unlink(path, 1, dbenv);
}
+
+ if (tmgrp->reginfo.path != NULL)
+ FREES(tmgrp->reginfo.path);
+ FREE(tmgrp, sizeof(*tmgrp));
return (ret);
}
@@ -244,77 +223,83 @@ txn_begin(tmgrp, parent, txnpp)
DB_TXN *parent;
DB_TXN **txnpp;
{
- TXN_DETAIL *txnp;
+ DB_LSN begin_lsn;
DB_TXN *retp;
- int id, ret;
+ TXN_DETAIL *txnp;
+ size_t off;
+ u_int32_t id;
+ int ret;
+
+ txnp = NULL;
+ *txnpp = NULL;
+
+ if ((retp = (DB_TXN *)__db_malloc(sizeof(DB_TXN))) == NULL) {
+ __db_err(tmgrp->dbenv, "txn_begin : %s", strerror(ENOMEM));
+ return (ENOMEM);
+ }
+
+ /*
+ * We do not have to write begin records (and if we do not, then we
+ * need never write records for read-only transactions). However,
+ * we do need to find the current LSN so that we can store it in the
+ * transaction structure, so we can know where to take checkpoints.
+ */
+ if (tmgrp->dbenv->lg_info != NULL && (ret =
+ log_put(tmgrp->dbenv->lg_info, &begin_lsn, NULL, DB_CURLSN)) != 0)
+ goto err2;
LOCK_TXNREGION(tmgrp);
+ /* Make sure that last_txnid is not going to wrap around. */
+ if (tmgrp->region->last_txnid == TXN_INVALID) {
+ __db_err(tmgrp->dbenv, "txn_begin: %s %s",
+ "Transaction ID wrapping.",
+ "Snapshot your database and start a new log.");
+ ret = EINVAL;
+ goto err1;
+ }
+
if ((ret = __txn_validate_region(tmgrp)) != 0)
- goto err;
+ goto err1;
/* Allocate a new transaction detail structure. */
if ((ret = __db_shalloc(tmgrp->mem, sizeof(TXN_DETAIL), 0, &txnp)) != 0
&& ret == ENOMEM && (ret = __txn_grow_region(tmgrp)) == 0)
ret = __db_shalloc(tmgrp->mem, sizeof(TXN_DETAIL), 0, &txnp);
-
if (ret != 0)
- goto err;
-
- /* Make sure that last_txnid is not going to wrap around. */
- if (tmgrp->region->last_txnid == TXN_INVALID)
- return (EINVAL);
-
- if ((retp = (DB_TXN *)__db_malloc(sizeof(DB_TXN))) == NULL) {
- __db_err(tmgrp->dbenv, "txn_begin : %s", strerror(ENOMEM));
- ret = ENOMEM;
goto err1;
- }
+
+ /* Place transaction on active transaction list. */
+ SH_TAILQ_INSERT_HEAD(&tmgrp->region->active_txn,
+ txnp, links, __txn_detail);
id = ++tmgrp->region->last_txnid;
tmgrp->region->nbegins++;
txnp->txnid = id;
+ txnp->begin_lsn = begin_lsn;
ZERO_LSN(txnp->last_lsn);
- ZERO_LSN(txnp->begin_lsn);
txnp->last_lock = 0;
txnp->status = TXN_RUNNING;
- SH_TAILQ_INSERT_HEAD(&tmgrp->region->active_txn,
- txnp, links, __txn_detail);
-
+ off = (u_int8_t *)txnp - (u_int8_t *)tmgrp->region;
UNLOCK_TXNREGION(tmgrp);
ZERO_LSN(retp->last_lsn);
retp->txnid = id;
retp->parent = parent;
- retp->off = (u_int8_t *)txnp - (u_int8_t *)tmgrp->region;
retp->mgrp = tmgrp;
-
- if (tmgrp->dbenv->lg_info != NULL &&
- (ret = __txn_regop_log(tmgrp->dbenv->lg_info,
- retp, &txnp->begin_lsn, 0, TXN_BEGIN)) != 0) {
-
- /* Deallocate transaction. */
- LOCK_TXNREGION(tmgrp);
- SH_TAILQ_REMOVE(&tmgrp->region->active_txn,
- txnp, links, __txn_detail);
- __db_shalloc_free(tmgrp->mem, txnp);
- UNLOCK_TXNREGION(tmgrp);
- __db_free(retp);
- return (ret);
- }
+ retp->off = off;
LOCK_TXNTHREAD(tmgrp);
TAILQ_INSERT_TAIL(&tmgrp->txn_chain, retp, links);
UNLOCK_TXNTHREAD(tmgrp);
- *txnpp = retp;
+ *txnpp = retp;
return (0);
-err1:
- __db_shalloc_free(tmgrp->mem, txnp);
-err:
- UNLOCK_TXNREGION(tmgrp);
+err1: UNLOCK_TXNREGION(tmgrp);
+
+err2: __db_free(retp);
return (ret);
}
@@ -332,12 +317,15 @@ txn_commit(txnp)
if ((ret = __txn_check_running(txnp)) != 0)
return (ret);
- /* Sync the log. */
+ /*
+ * If there are any log records, write a log record and sync
+ * the log, else do no log writes.
+ */
if ((logp = txnp->mgrp->dbenv->lg_info) != NULL &&
- (ret = __txn_regop_log(logp,
- txnp, &txnp->last_lsn,
- F_ISSET(txnp->mgrp, DB_TXN_NOSYNC) ? 0 : DB_FLUSH, TXN_COMMIT))
- != 0)
+ !IS_ZERO_LSN(txnp->last_lsn) &&
+ (ret = __txn_regop_log(logp, txnp, &txnp->last_lsn,
+ F_ISSET(txnp->mgrp, DB_TXN_NOSYNC) ? 0 : DB_FLUSH,
+ TXN_COMMIT)) != 0)
return (ret);
return (__txn_end(txnp, 1));
@@ -371,8 +359,8 @@ int
txn_prepare(txnp)
DB_TXN *txnp;
{
- int ret;
TXN_DETAIL *tp;
+ int ret;
if ((ret = __txn_check_running(txnp)) != 0)
return (ret);
@@ -414,21 +402,23 @@ txn_close(tmgrp)
DB_TXN *txnp;
int ret, t_ret;
+ ret = 0;
+
/*
* This function had better only be called once per process
* (i.e., not per thread), so there should be no synchronization
* required.
*/
- for (ret = 0, txnp = TAILQ_FIRST(&tmgrp->txn_chain);
- txnp != TAILQ_END(&tmgrp->txn_chain);
- txnp = TAILQ_FIRST(&tmgrp->txn_chain)) {
- if ((t_ret = txn_abort(txnp)) != 0 && ret == 0)
- ret = t_ret;
- }
+ while ((txnp =
+ TAILQ_FIRST(&tmgrp->txn_chain)) != TAILQ_END(&tmgrp->txn_chain))
+ if ((t_ret = txn_abort(txnp)) != 0) {
+ __txn_end(txnp, 0);
+ if (ret == 0)
+ ret = t_ret;
+ }
- if (tmgrp->dbenv->lg_info && (t_ret =
- log_flush(tmgrp->dbenv->lg_info, NULL)) != 0 &&
- ret == 0)
+ if (tmgrp->dbenv->lg_info &&
+ (t_ret = log_flush(tmgrp->dbenv->lg_info, NULL)) != 0 && ret == 0)
ret = t_ret;
if (tmgrp->mutexp != NULL) {
@@ -437,12 +427,12 @@ txn_close(tmgrp)
UNLOCK_TXNREGION(tmgrp);
}
- if ((t_ret = __db_rclose(tmgrp->dbenv, tmgrp->fd, tmgrp->region)) != 0
- && ret == 0)
+ if ((t_ret = __db_rdetach(&tmgrp->reginfo)) != 0 && ret == 0)
ret = t_ret;
- if (ret == 0)
- __db_free(tmgrp);
+ if (tmgrp->reginfo.path != NULL)
+ FREES(tmgrp->reginfo.path);
+ FREE(tmgrp, sizeof(*tmgrp));
return (ret);
}
@@ -457,8 +447,19 @@ txn_unlink(path, force, dbenv)
int force;
DB_ENV *dbenv;
{
- return (__db_runlink(dbenv,
- DB_APP_NONE, path, DEFAULT_TXN_FILE, force));
+ REGINFO reginfo;
+ int ret;
+
+ memset(&reginfo, 0, sizeof(reginfo));
+ reginfo.dbenv = dbenv;
+ reginfo.appname = DB_APP_NONE;
+ if (path != NULL && (reginfo.path = (char *)__db_strdup(path)) == NULL)
+ return (ENOMEM);
+ reginfo.file = DEFAULT_TXN_FILE;
+ ret = __db_runlink(&reginfo, force);
+ if (reginfo.path != NULL)
+ FREES(reginfo.path);
+ return (ret);
}
/* Internal routines. */
@@ -540,10 +541,10 @@ static int
__txn_undo(txnp)
DB_TXN *txnp;
{
- DB_TXNMGR *mgr;
- DB_LOG *logp;
DBT rdbt;
+ DB_LOG *logp;
DB_LSN key_lsn;
+ DB_TXNMGR *mgr;
int ret;
mgr = txnp->mgrp;
@@ -594,7 +595,7 @@ __txn_undo(txnp)
int
txn_checkpoint(mgr, kbytes, minutes)
const DB_TXNMGR *mgr;
- int kbytes, minutes;
+ u_int32_t kbytes, minutes;
{
TXN_DETAIL *txnp;
DB_LSN ckp_lsn, last_ckp;
@@ -603,10 +604,6 @@ txn_checkpoint(mgr, kbytes, minutes)
time_t last_ckp_time, now;
int ret;
- /* Check usage. */
- if (kbytes < 0 || minutes < 0)
- return (EINVAL);
-
/*
* Check if we need to run recovery.
*/
@@ -678,8 +675,8 @@ do_ckp:
if (mgr->dbenv->mp_info != NULL &&
(ret = memp_sync(mgr->dbenv->mp_info, &ckp_lsn)) != 0) {
/*
- * ret < 0 means that there are still buffers to flush;
- * the checkpoint is not complete. Back off and try again.
+ * ret == DB_INCOMPLETE means that there are still buffers to
+ * flush, the checkpoint is not complete. Wait and try again.
*/
if (ret > 0)
__db_err(mgr->dbenv,
@@ -711,9 +708,9 @@ do_ckp:
}
/*
- * This is called at every interface to verify if the region
- * has changed size, and if so, to remap the region in and
- * reset the process pointers.
+ * __txn_validate_region --
+ * Called at every interface to verify if the region has changed size,
+ * and if so, to remap the region in and reset the process' pointers.
*/
static int
__txn_validate_region(tp)
@@ -721,15 +718,15 @@ __txn_validate_region(tp)
{
int ret;
- if (tp->reg_size == tp->region->hdr.size)
+ if (tp->reginfo.size == tp->region->hdr.size)
return (0);
- /* Grow the region. */
- if ((ret = __db_rremap(tp->dbenv, tp->region,
- tp->reg_size, tp->region->hdr.size, tp->fd, &tp->region)) != 0)
+ /* Detach/reattach the region. */
+ if ((ret = __db_rreattach(&tp->reginfo, tp->region->hdr.size)) != 0)
return (ret);
- tp->reg_size = tp->region->hdr.size;
+ /* Reset region information. */
+ tp->region = tp->reginfo.addr;
tp->mem = &tp->region[1];
return (0);
@@ -739,27 +736,26 @@ static int
__txn_grow_region(tp)
DB_TXNMGR *tp;
{
- size_t incr;
+ size_t incr, oldsize;
u_int32_t mutex_offset, oldmax;
u_int8_t *curaddr;
int ret;
oldmax = tp->region->maxtxns;
incr = oldmax * sizeof(DB_TXN);
- mutex_offset = (u_int8_t *)tp->mutexp - (u_int8_t *)tp->region;
+ mutex_offset = tp->mutexp != NULL ?
+ (u_int8_t *)tp->mutexp - (u_int8_t *)tp->region : 0;
- if ((ret = __db_rgrow(tp->dbenv, tp->fd, incr)) != 0)
- return (ret);
-
- if ((ret = __db_rremap(tp->dbenv, tp->region,
- tp->reg_size, tp->reg_size + incr, tp->fd, &tp->region)) != 0)
+ oldsize = tp->reginfo.size;
+ if ((ret = __db_rgrow(&tp->reginfo, oldsize + incr)) != 0)
return (ret);
+ tp->region = tp->reginfo.addr;
/* Throw the new space on the free list. */
- curaddr = (u_int8_t *)tp->region + tp->reg_size;
+ curaddr = (u_int8_t *)tp->region + oldsize;
tp->mem = &tp->region[1];
- tp->reg_size += incr;
- tp->mutexp = (db_mutex_t *)((u_int8_t *)tp->region + mutex_offset);
+ tp->mutexp = mutex_offset != 0 ?
+ (db_mutex_t *)((u_int8_t *)tp->region + mutex_offset) : NULL;
*((size_t *)curaddr) = incr - sizeof(size_t);
curaddr += sizeof(size_t);
@@ -826,6 +822,11 @@ txn_stat(mgr, statp, db_malloc)
break;
}
+ stats->st_region_wait = mgr->region->hdr.lock.mutex_set_wait;
+ stats->st_region_nowait = mgr->region->hdr.lock.mutex_set_nowait;
+ stats->st_refcnt = mgr->region->hdr.refcnt;
+ stats->st_regsize = mgr->region->hdr.size;
+
UNLOCK_TXNREGION(mgr);
*statp = stats;
return (0);