OpenSolaris_b135/cmd/sendmail/db/txn/txn.c
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997, 1998
* Sleepycat Software. All rights reserved.
*/
/*
* Copyright (c) 1995, 1996
* The President and Fellows of Harvard University. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Margo Seltzer.
*
* 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.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)txn.c 10.66 (Sleepycat) 1/3/99";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#endif
#include "db_int.h"
#include "shqueue.h"
#include "db_page.h"
#include "db_shash.h"
#include "txn.h"
#include "db_dispatch.h"
#include "lock.h"
#include "log.h"
#include "db_am.h"
#include "common_ext.h"
static int __txn_begin __P((DB_TXN *));
static int __txn_check_running __P((const DB_TXN *, TXN_DETAIL **));
static int __txn_end __P((DB_TXN *, int));
static void __txn_freekids __P((DB_TXN *));
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 *));
/*
* This file contains the top level routines of the transaction library.
* It assumes that a lock manager and log manager that conform to the db_log(3)
* and db_lock(3) interfaces exist.
*
* Initialize a transaction region in shared memory.
* Return 0 on success, errno on failure.
*/
static int
__txn_init(txn_region)
DB_TXNREGION *txn_region;
{
time_t now;
(void)time(&now);
/* maxtxns is already initialized. */
txn_region->magic = DB_TXNMAGIC;
txn_region->version = DB_TXNVERSION;
txn_region->last_txnid = TXN_MINIMUM;
/*
* XXX
* If we ever do more types of locking and logging, this changes.
*/
txn_region->logtype = 0;
txn_region->locktype = 0;
txn_region->time_ckp = now;
ZERO_LSN(txn_region->last_ckp);
ZERO_LSN(txn_region->pending_ckp);
SH_TAILQ_INIT(&txn_region->active_txn);
__db_shalloc_init((void *)&txn_region[1],
TXN_REGION_SIZE(txn_region->maxtxns) - sizeof(DB_TXNREGION));
return (0);
}
int
txn_open(path, flags, mode, dbenv, mgrpp)
const char *path;
u_int32_t flags;
int mode;
DB_ENV *dbenv;
DB_TXNMGR **mgrpp;
{
DB_TXNMGR *tmgrp;
u_int32_t maxtxns;
int ret;
/* Validate arguments. */
if (dbenv == NULL)
return (EINVAL);
#ifdef HAVE_SPINLOCKS
#define OKFLAGS (DB_CREATE | DB_THREAD | DB_TXN_NOSYNC)
#else
#define OKFLAGS (DB_CREATE | DB_TXN_NOSYNC)
#endif
if ((ret = __db_fchk(dbenv, "txn_open", flags, OKFLAGS)) != 0)
return (ret);
maxtxns = dbenv->tx_max != 0 ? dbenv->tx_max : 20;
/* Now, create the transaction manager structure and set its fields. */
if ((ret = __os_calloc(1, sizeof(DB_TXNMGR), &tmgrp)) != 0)
return (ret);
/* Initialize the transaction manager structure. */
tmgrp->mutexp = NULL;
tmgrp->dbenv = dbenv;
tmgrp->recover =
dbenv->tx_recover == NULL ? __db_dispatch : dbenv->tx_recover;
tmgrp->flags = LF_ISSET(DB_TXN_NOSYNC | DB_THREAD);
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 ((ret = __os_strdup(path, &tmgrp->reginfo.path)) != 0)
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)) {
if ((ret = __db_shalloc(tmgrp->mem, sizeof(db_mutex_t),
MUTEX_ALIGNMENT, &tmgrp->mutexp)) == 0)
/*
* Since we only get here if threading is turned on, we
* know that we have spinlocks, so the offset is going
* to be ignored. We put 0 here as a valid placeholder.
*/
__db_mutex_init(tmgrp->mutexp, 0);
if (ret != 0)
goto err;
}
UNLOCK_TXNREGION(tmgrp);
*mgrpp = tmgrp;
return (0);
err: if (tmgrp->reginfo.addr != NULL) {
if (tmgrp->mutexp != NULL)
__db_shalloc_free(tmgrp->mem, tmgrp->mutexp);
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)
__os_freestr(tmgrp->reginfo.path);
__os_free(tmgrp, sizeof(*tmgrp));
return (ret);
}
/*
* __txn_panic --
* Panic a transaction region.
*
* PUBLIC: void __txn_panic __P((DB_ENV *));
*/
void
__txn_panic(dbenv)
DB_ENV *dbenv;
{
if (dbenv->tx_info != NULL)
dbenv->tx_info->region->hdr.panic = 1;
}
/*
* txn_begin --
* This is a wrapper to the actual begin process. Normal txn_begin()
* allocates a DB_TXN structure for the caller, while txn_xa_begin() does
* not. Other than that, both call into the common __txn_begin code().
*
* Internally, we use TXN_DETAIL structures, but the DB_TXN structure
* provides access to the transaction ID and the offset in the transaction
* region of the TXN_DETAIL structure.
*/
int
txn_begin(tmgrp, parent, txnpp)
DB_TXNMGR *tmgrp;
DB_TXN *parent, **txnpp;
{
DB_TXN *txn;
int ret;
TXN_PANIC_CHECK(tmgrp);
if ((ret = __os_calloc(1, sizeof(DB_TXN), &txn)) != 0)
return (ret);
txn->parent = parent;
TAILQ_INIT(&txn->kids);
txn->mgrp = tmgrp;
txn->flags = TXN_MALLOC;
if ((ret = __txn_begin(txn)) != 0) {
__os_free(txn, sizeof(DB_TXN));
txn = NULL;
}
if (txn != NULL && parent != NULL)
TAILQ_INSERT_HEAD(&parent->kids, txn, klinks);
*txnpp = txn;
return (ret);
}
/*
* __txn_xa_begin --
* XA version of txn_begin.
*
* PUBLIC: int __txn_xa_begin __P((DB_ENV *, DB_TXN *));
*/
int
__txn_xa_begin(dbenv, txn)
DB_ENV *dbenv;
DB_TXN *txn;
{
TXN_PANIC_CHECK(dbenv->tx_info);
memset(txn, 0, sizeof(DB_TXN));
txn->mgrp = dbenv->tx_info;
return (__txn_begin(txn));
}
/*
* __txn_begin --
* Normal DB version of txn_begin.
*/
static int
__txn_begin(txn)
DB_TXN *txn;
{
DB_LSN begin_lsn;
DB_TXNMGR *mgr;
TXN_DETAIL *td;
size_t off;
u_int32_t id;
int ret;
/*
* 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.
*/
mgr = txn->mgrp;
if (mgr->dbenv->lg_info != NULL && (ret =
log_put(mgr->dbenv->lg_info, &begin_lsn, NULL, DB_CURLSN)) != 0)
goto err2;
LOCK_TXNREGION(mgr);
/* Make sure that last_txnid is not going to wrap around. */
if (mgr->region->last_txnid == TXN_INVALID) {
__db_err(mgr->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(mgr)) != 0)
goto err1;
/* Allocate a new transaction detail structure. */
if ((ret = __db_shalloc(mgr->mem, sizeof(TXN_DETAIL), 0, &td)) != 0
&& ret == ENOMEM && (ret = __txn_grow_region(mgr)) == 0)
ret = __db_shalloc(mgr->mem, sizeof(TXN_DETAIL), 0, &td);
if (ret != 0)
goto err1;
/* Place transaction on active transaction list. */
SH_TAILQ_INSERT_HEAD(&mgr->region->active_txn, td, links, __txn_detail);
id = ++mgr->region->last_txnid;
++mgr->region->nbegins;
td->txnid = id;
td->begin_lsn = begin_lsn;
ZERO_LSN(td->last_lsn);
td->last_lock = 0;
td->status = TXN_RUNNING;
if (txn->parent != NULL)
td->parent = txn->parent->off;
else
td->parent = 0;
off = (u_int8_t *)td - (u_int8_t *)mgr->region;
UNLOCK_TXNREGION(mgr);
ZERO_LSN(txn->last_lsn);
txn->txnid = id;
txn->off = off;
if (F_ISSET(txn, TXN_MALLOC)) {
LOCK_TXNTHREAD(mgr);
TAILQ_INSERT_TAIL(&mgr->txn_chain, txn, links);
UNLOCK_TXNTHREAD(mgr);
}
return (0);
err1: UNLOCK_TXNREGION(mgr);
err2: return (ret);
}
/*
* txn_commit --
* Commit a transaction.
*/
int
txn_commit(txnp)
DB_TXN *txnp;
{
DB_LOG *logp;
DB_TXNMGR *mgr;
int ret;
mgr = txnp->mgrp;
TXN_PANIC_CHECK(mgr);
if ((ret = __txn_check_running(txnp, NULL)) != 0)
return (ret);
/*
* If there are any log records, write a log record and sync
* the log, else do no log writes. If the commit is for a child
* transaction, we do not need to commit the child synchronously
* since if its parent aborts, it will abort too and its parent
* (or ultimate ancestor) will write synchronously.
*/
if ((logp = mgr->dbenv->lg_info) != NULL &&
!IS_ZERO_LSN(txnp->last_lsn)) {
if (txnp->parent == NULL)
ret = __txn_regop_log(logp, txnp, &txnp->last_lsn,
F_ISSET(mgr, DB_TXN_NOSYNC) ? 0 : DB_FLUSH,
TXN_COMMIT);
else
ret = __txn_child_log(logp, txnp, &txnp->last_lsn, 0,
TXN_COMMIT, txnp->parent->txnid);
if (ret != 0)
return (ret);
}
/*
* If this is the senior ancestor (i.e., it has no children), then we
* can release all the child transactions since everyone is committing.
* Then we can release this transaction. If this is not the ultimate
* ancestor, then we can neither free it or its children.
*/
if (txnp->parent == NULL)
__txn_freekids(txnp);
return (__txn_end(txnp, 1));
}
/*
* txn_abort --
* Abort a transcation.
*/
int
txn_abort(txnp)
DB_TXN *txnp;
{
int ret;
DB_TXN *kids;
TXN_PANIC_CHECK(txnp->mgrp);
if ((ret = __txn_check_running(txnp, NULL)) != 0)
return (ret);
for (kids = TAILQ_FIRST(&txnp->kids);
kids != NULL;
kids = TAILQ_FIRST(&txnp->kids))
txn_abort(kids);
if ((ret = __txn_undo(txnp)) != 0) {
__db_err(txnp->mgrp->dbenv,
"txn_abort: Log undo failed %s", strerror(ret));
return (ret);
}
return (__txn_end(txnp, 0));
}
/*
* txn_prepare --
* Flush the log so a future commit is guaranteed to succeed.
*/
int
txn_prepare(txnp)
DB_TXN *txnp;
{
DBT xid;
DB_ENV *dbenv;
TXN_DETAIL *td;
int ret;
if ((ret = __txn_check_running(txnp, &td)) != 0)
return (ret);
dbenv = txnp->mgrp->dbenv;
memset(&xid, 0, sizeof(xid));
xid.data = td->xid;
/*
* We indicate that a transaction is an XA transaction by putting
* a valid size in the xid.size fiels. XA requires that the transaction
* be either ENDED or SUSPENDED when prepare is called, so we know
* that if the xa_status isn't in one of those states, but we are
* calling prepare that we are not an XA transaction.
*/
xid.size =
td->xa_status != TXN_XA_ENDED && td->xa_status != TXN_XA_SUSPENDED ?
0 : sizeof(td->xid);
if (dbenv->lg_info != NULL &&
(ret = __txn_xa_regop_log(dbenv->lg_info, txnp, &txnp->last_lsn,
F_ISSET(txnp->mgrp, DB_TXN_NOSYNC) ? 0 : DB_FLUSH, TXN_PREPARE,
&xid, td->format, td->gtrid, td->bqual, &td->begin_lsn)) != 0) {
__db_err(dbenv,
"txn_prepare: log_write failed %s\n", strerror(ret));
return (ret);
}
LOCK_TXNTHREAD(txnp->mgrp);
td->status = TXN_PREPARED;
UNLOCK_TXNTHREAD(txnp->mgrp);
return (ret);
}
/*
* Return the transaction ID associated with a particular transaction
*/
u_int32_t
txn_id(txnp)
DB_TXN *txnp;
{
return (txnp->txnid);
}
/*
* txn_close --
* Close the transaction region, does not imply a checkpoint.
*/
int
txn_close(tmgrp)
DB_TXNMGR *tmgrp;
{
DB_TXN *txnp;
int ret, t_ret;
TXN_PANIC_CHECK(tmgrp);
ret = 0;
/*
* This function had better only be called once per process
* (i.e., not per thread), so there should be no synchronization
* required.
*/
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)
ret = t_ret;
if (tmgrp->mutexp != NULL) {
LOCK_TXNREGION(tmgrp);
__db_shalloc_free(tmgrp->mem, tmgrp->mutexp);
UNLOCK_TXNREGION(tmgrp);
}
if ((t_ret = __db_rdetach(&tmgrp->reginfo)) != 0 && ret == 0)
ret = t_ret;
if (tmgrp->reginfo.path != NULL)
__os_freestr(tmgrp->reginfo.path);
__os_free(tmgrp, sizeof(*tmgrp));
return (ret);
}
/*
* txn_unlink --
* Remove the transaction region.
*/
int
txn_unlink(path, force, dbenv)
const char *path;
int force;
DB_ENV *dbenv;
{
REGINFO reginfo;
int ret;
memset(®info, 0, sizeof(reginfo));
reginfo.dbenv = dbenv;
reginfo.appname = DB_APP_NONE;
if (path != NULL && (ret = __os_strdup(path, ®info.path)) != 0)
return (ret);
reginfo.file = DEFAULT_TXN_FILE;
ret = __db_runlink(®info, force);
if (reginfo.path != NULL)
__os_freestr(reginfo.path);
return (ret);
}
/* Internal routines. */
/*
* Return 0 if the txnp is reasonable, otherwise returns EINVAL.
*/
static int
__txn_check_running(txnp, tdp)
const DB_TXN *txnp;
TXN_DETAIL **tdp;
{
TXN_DETAIL *tp;
tp = NULL;
if (txnp != NULL && txnp->mgrp != NULL && txnp->mgrp->region != NULL) {
tp = (TXN_DETAIL *)((u_int8_t *)txnp->mgrp->region + txnp->off);
/*
* Child transactions could be marked committed which is OK.
*/
if (tp->status != TXN_RUNNING &&
tp->status != TXN_PREPARED && tp->status != TXN_COMMITTED)
tp = NULL;
if (tdp != NULL)
*tdp = tp;
}
return (tp == NULL ? EINVAL : 0);
}
static int
__txn_end(txnp, is_commit)
DB_TXN *txnp;
int is_commit;
{
DB_LOCKREQ request;
DB_TXNMGR *mgr;
TXN_DETAIL *tp;
u_int32_t locker;
int ret;
mgr = txnp->mgrp;
/* Release the locks. */
locker = txnp->txnid;
request.op = txnp->parent == NULL ||
is_commit == 0 ? DB_LOCK_PUT_ALL : DB_LOCK_INHERIT;
if (mgr->dbenv->lk_info) {
ret =
lock_tvec(mgr->dbenv->lk_info, txnp, 0, &request, 1, NULL);
if (ret != 0 && (ret != DB_LOCK_DEADLOCK || is_commit)) {
__db_err(mgr->dbenv, "%s: release locks failed %s",
is_commit ? "txn_commit" : "txn_abort",
strerror(ret));
return (ret);
}
}
/* End the transaction. */
LOCK_TXNREGION(mgr);
/*
* Child transactions that are committing cannot be released until
* the parent commits, since the parent may abort, causing the child
* to abort as well.
*/
tp = (TXN_DETAIL *)((u_int8_t *)mgr->region + txnp->off);
if (txnp->parent == NULL || !is_commit) {
SH_TAILQ_REMOVE(&mgr->region->active_txn,
tp, links, __txn_detail);
__db_shalloc_free(mgr->mem, tp);
} else
tp->status = is_commit ? TXN_COMMITTED : TXN_ABORTED;
if (is_commit)
mgr->region->ncommits++;
else
mgr->region->naborts++;
UNLOCK_TXNREGION(mgr);
/*
* If the transaction aborted, we can remove it from its parent links.
* If it committed, then we need to leave it on, since the parent can
* still abort.
*/
if (txnp->parent != NULL && !is_commit)
TAILQ_REMOVE(&txnp->parent->kids, txnp, klinks);
/* Free the space. */
if (F_ISSET(txnp, TXN_MALLOC) && (txnp->parent == NULL || !is_commit)) {
LOCK_TXNTHREAD(mgr);
TAILQ_REMOVE(&mgr->txn_chain, txnp, links);
UNLOCK_TXNTHREAD(mgr);
__os_free(txnp, sizeof(*txnp));
}
return (0);
}
/*
* __txn_undo --
* Undo the transaction with id txnid. Returns 0 on success and
* errno on failure.
*/
static int
__txn_undo(txnp)
DB_TXN *txnp;
{
DBT rdbt;
DB_LOG *logp;
DB_LSN key_lsn;
DB_TXNMGR *mgr;
int ret;
mgr = txnp->mgrp;
logp = mgr->dbenv->lg_info;
if (logp == NULL)
return (0);
/*
* This is the simplest way to code this, but if the mallocs during
* recovery turn out to be a performance issue, we can do the
* allocation here and use DB_DBT_USERMEM.
*/
memset(&rdbt, 0, sizeof(rdbt));
if (F_ISSET(logp, DB_AM_THREAD))
F_SET(&rdbt, DB_DBT_MALLOC);
key_lsn = txnp->last_lsn; /* structure assignment */
for (ret = 0; ret == 0 && !IS_ZERO_LSN(key_lsn);) {
/*
* The dispatch routine returns the lsn of the record
* before the current one in the key_lsn argument.
*/
if ((ret = log_get(logp, &key_lsn, &rdbt, DB_SET)) == 0) {
ret =
mgr->recover(logp, &rdbt, &key_lsn, TXN_UNDO, NULL);
if (F_ISSET(logp, DB_AM_THREAD) && rdbt.data != NULL) {
__os_free(rdbt.data, rdbt.size);
rdbt.data = NULL;
}
}
if (ret != 0)
return (ret);
}
return (ret);
}
/*
* Transaction checkpoint.
* If either kbytes or minutes is non-zero, then we only take the checkpoint
* more than "minutes" minutes have passed since the last checkpoint or if
* more than "kbytes" of log data have been written since the last checkpoint.
* When taking a checkpoint, find the oldest active transaction and figure out
* its first LSN. This is the lowest LSN we can checkpoint, since any record
* written after since that point may be involved in a transaction and may
* therefore need to be undone in the case of an abort.
*/
int
txn_checkpoint(mgr, kbytes, minutes)
const DB_TXNMGR *mgr;
u_int32_t kbytes, minutes;
{
DB_LOG *dblp;
DB_LSN ckp_lsn, sync_lsn, last_ckp;
TXN_DETAIL *txnp;
time_t last_ckp_time, now;
u_int32_t kbytes_written;
int ret;
TXN_PANIC_CHECK(mgr);
/*
* Check if we need to run recovery.
*/
ZERO_LSN(ckp_lsn);
if (minutes != 0) {
(void)time(&now);
LOCK_TXNREGION(mgr);
last_ckp_time = mgr->region->time_ckp;
UNLOCK_TXNREGION(mgr);
if (now - last_ckp_time >= (time_t)(minutes * 60))
goto do_ckp;
}
if (kbytes != 0) {
dblp = mgr->dbenv->lg_info;
LOCK_LOGREGION(dblp);
kbytes_written =
dblp->lp->stat.st_wc_mbytes * 1024 +
dblp->lp->stat.st_wc_bytes / 1024;
ckp_lsn = dblp->lp->lsn;
UNLOCK_LOGREGION(dblp);
if (kbytes_written >= (u_int32_t)kbytes)
goto do_ckp;
}
/*
* If we checked time and data and didn't go to checkpoint,
* we're done.
*/
if (minutes != 0 || kbytes != 0)
return (0);
do_ckp:
if (IS_ZERO_LSN(ckp_lsn)) {
dblp = mgr->dbenv->lg_info;
LOCK_LOGREGION(dblp);
ckp_lsn = dblp->lp->lsn;
UNLOCK_LOGREGION(dblp);
}
/*
* We have to find an LSN such that all transactions begun
* before that LSN are complete.
*/
LOCK_TXNREGION(mgr);
if (!IS_ZERO_LSN(mgr->region->pending_ckp))
ckp_lsn = mgr->region->pending_ckp;
else
for (txnp =
SH_TAILQ_FIRST(&mgr->region->active_txn, __txn_detail);
txnp != NULL;
txnp = SH_TAILQ_NEXT(txnp, links, __txn_detail)) {
/*
* Look through the active transactions for the
* lowest begin lsn.
*/
if (!IS_ZERO_LSN(txnp->begin_lsn) &&
log_compare(&txnp->begin_lsn, &ckp_lsn) < 0)
ckp_lsn = txnp->begin_lsn;
}
mgr->region->pending_ckp = ckp_lsn;
UNLOCK_TXNREGION(mgr);
/*
* memp_sync may change the lsn you pass it, so don't pass it
* the actual ckp_lsn, pass it a temp instead.
*/
sync_lsn = ckp_lsn;
if (mgr->dbenv->mp_info != NULL &&
(ret = memp_sync(mgr->dbenv->mp_info, &sync_lsn)) != 0) {
/*
* 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,
"txn_checkpoint: system failure in memp_sync %s\n",
strerror(ret));
return (ret);
}
if (mgr->dbenv->lg_info != NULL) {
LOCK_TXNREGION(mgr);
last_ckp = mgr->region->last_ckp;
ZERO_LSN(mgr->region->pending_ckp);
UNLOCK_TXNREGION(mgr);
if ((ret = __txn_ckp_log(mgr->dbenv->lg_info,
NULL, &ckp_lsn, DB_CHECKPOINT, &ckp_lsn, &last_ckp)) != 0) {
__db_err(mgr->dbenv,
"txn_checkpoint: log failed at LSN [%ld %ld] %s\n",
(long)ckp_lsn.file, (long)ckp_lsn.offset,
strerror(ret));
return (ret);
}
LOCK_TXNREGION(mgr);
mgr->region->last_ckp = ckp_lsn;
(void)time(&mgr->region->time_ckp);
UNLOCK_TXNREGION(mgr);
}
return (0);
}
/*
* __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)
DB_TXNMGR *tp;
{
int ret;
if (tp->reginfo.size == tp->region->hdr.size)
return (0);
/* Detach/reattach the region. */
if ((ret = __db_rreattach(&tp->reginfo, tp->region->hdr.size)) != 0)
return (ret);
/* Reset region information. */
tp->region = tp->reginfo.addr;
tp->mem = &tp->region[1];
return (0);
}
static int
__txn_grow_region(tp)
DB_TXNMGR *tp;
{
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 = tp->mutexp != NULL ?
(u_int8_t *)tp->mutexp - (u_int8_t *)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 + oldsize;
tp->mem = &tp->region[1];
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);
__db_shalloc_free(tp->mem, curaddr);
tp->region->maxtxns = 2 * oldmax;
return (0);
}
int
txn_stat(mgr, statp, db_malloc)
DB_TXNMGR *mgr;
DB_TXN_STAT **statp;
void *(*db_malloc) __P((size_t));
{
DB_TXN_STAT *stats;
TXN_DETAIL *txnp;
size_t nbytes;
u_int32_t nactive, ndx;
int ret;
TXN_PANIC_CHECK(mgr);
LOCK_TXNREGION(mgr);
nactive = mgr->region->nbegins -
mgr->region->naborts - mgr->region->ncommits;
UNLOCK_TXNREGION(mgr);
/*
* Allocate a bunch of extra active structures to handle any
* that have been created since we unlocked the region.
*/
nbytes = sizeof(DB_TXN_STAT) + sizeof(DB_TXN_ACTIVE) * (nactive + 200);
if ((ret = __os_malloc(nbytes, db_malloc, &stats)) != 0)
return (ret);
LOCK_TXNREGION(mgr);
stats->st_last_txnid = mgr->region->last_txnid;
stats->st_last_ckp = mgr->region->last_ckp;
stats->st_maxtxns = mgr->region->maxtxns;
stats->st_naborts = mgr->region->naborts;
stats->st_nbegins = mgr->region->nbegins;
stats->st_ncommits = mgr->region->ncommits;
stats->st_pending_ckp = mgr->region->pending_ckp;
stats->st_time_ckp = mgr->region->time_ckp;
stats->st_nactive = stats->st_nbegins -
stats->st_naborts - stats->st_ncommits;
if (stats->st_nactive > nactive + 200)
stats->st_nactive = nactive + 200;
stats->st_txnarray = (DB_TXN_ACTIVE *)&stats[1];
ndx = 0;
for (txnp = SH_TAILQ_FIRST(&mgr->region->active_txn, __txn_detail);
txnp != NULL;
txnp = SH_TAILQ_NEXT(txnp, links, __txn_detail)) {
stats->st_txnarray[ndx].txnid = txnp->txnid;
stats->st_txnarray[ndx].lsn = txnp->begin_lsn;
ndx++;
if (ndx >= stats->st_nactive)
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);
}
static void
__txn_freekids(txnp)
DB_TXN *txnp;
{
DB_TXNMGR *mgr;
TXN_DETAIL *tp;
DB_TXN *kids;
mgr = txnp->mgrp;
for (kids = TAILQ_FIRST(&txnp->kids);
kids != NULL;
kids = TAILQ_FIRST(&txnp->kids)) {
/* Free any children of this transaction. */
__txn_freekids(kids);
/* Free the transaction detail in the region. */
LOCK_TXNREGION(mgr);
tp = (TXN_DETAIL *)((u_int8_t *)mgr->region + kids->off);
SH_TAILQ_REMOVE(&mgr->region->active_txn,
tp, links, __txn_detail);
__db_shalloc_free(mgr->mem, tp);
UNLOCK_TXNREGION(mgr);
/* Now remove from its parent. */
TAILQ_REMOVE(&txnp->kids, kids, klinks);
if (F_ISSET(txnp, TXN_MALLOC)) {
LOCK_TXNTHREAD(mgr);
TAILQ_REMOVE(&mgr->txn_chain, kids, links);
UNLOCK_TXNTHREAD(mgr);
__os_free(kids, sizeof(*kids));
}
}
}
/*
* __txn_is_ancestor --
* Determine if a transaction is an ancestor of another transaction.
* This is used during lock promotion when we do not have the per-process
* data structures that link parents together. Instead, we'll have to
* follow the links in the transaction region.
*
* PUBLIC: int __txn_is_ancestor __P((DB_TXNMGR *, size_t, size_t));
*/
int
__txn_is_ancestor(mgr, hold_off, req_off)
DB_TXNMGR *mgr;
size_t hold_off, req_off;
{
TXN_DETAIL *hold_tp, *req_tp;
hold_tp = (TXN_DETAIL *)((u_int8_t *)mgr->region + hold_off);
req_tp = (TXN_DETAIL *)((u_int8_t *)mgr->region + req_off);
while (req_tp->parent != 0) {
req_tp =
(TXN_DETAIL *)((u_int8_t *)mgr->region + req_tp->parent);
if (req_tp->txnid == hold_tp->txnid)
return (1);
}
return (0);
}