Files
cpython-source-deps/txn/txn_recover.c
2017-09-04 13:40:25 -05:00

355 lines
8.9 KiB
C

/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2001,2008 Oracle. All rights reserved.
*
* $Id: txn_recover.c 63573 2008-05-23 21:43:21Z trent.nelson $
*/
#include "db_config.h"
#include "db_int.h"
#include "dbinc/txn.h"
#include "dbinc/db_page.h"
#include "dbinc/db_dispatch.h"
#include "dbinc/log.h"
#include "dbinc_auto/db_auto.h"
#include "dbinc_auto/crdel_auto.h"
#include "dbinc_auto/db_ext.h"
/*
* __txn_map_gid
* Return the txn that corresponds to this global ID.
*
* PUBLIC: int __txn_map_gid __P((ENV *,
* PUBLIC: u_int8_t *, TXN_DETAIL **, roff_t *));
*/
int
__txn_map_gid(env, gid, tdp, offp)
ENV *env;
u_int8_t *gid;
TXN_DETAIL **tdp;
roff_t *offp;
{
DB_TXNMGR *mgr;
DB_TXNREGION *region;
mgr = env->tx_handle;
region = mgr->reginfo.primary;
/*
* Search the internal active transaction table to find the
* matching xid. If this is a performance hit, then we
* can create a hash table, but I doubt it's worth it.
*/
TXN_SYSTEM_LOCK(env);
SH_TAILQ_FOREACH(*tdp, &region->active_txn, links, __txn_detail)
if (memcmp(gid, (*tdp)->xid, sizeof((*tdp)->xid)) == 0)
break;
TXN_SYSTEM_UNLOCK(env);
if (*tdp == NULL)
return (EINVAL);
*offp = R_OFFSET(&mgr->reginfo, *tdp);
return (0);
}
/*
* __txn_recover_pp --
* ENV->txn_recover pre/post processing.
*
* PUBLIC: int __txn_recover_pp
* PUBLIC: __P((DB_ENV *, DB_PREPLIST *, long, long *, u_int32_t));
*/
int
__txn_recover_pp(dbenv, preplist, count, retp, flags)
DB_ENV *dbenv;
DB_PREPLIST *preplist;
long count, *retp;
u_int32_t flags;
{
DB_THREAD_INFO *ip;
ENV *env;
int ret;
env = dbenv->env;
ENV_REQUIRES_CONFIG(
env, env->tx_handle, "txn_recover", DB_INIT_TXN);
if (F_ISSET((DB_TXNREGION *)env->tx_handle->reginfo.primary,
TXN_IN_RECOVERY)) {
__db_errx(env, "operation not permitted while in recovery");
return (EINVAL);
}
if (flags != DB_FIRST && flags != DB_NEXT)
return (__db_ferr(env, "DB_ENV->txn_recover", 0));
ENV_ENTER(env, ip);
REPLICATION_WRAP(env,
(__txn_recover(env, preplist, count, retp, flags)), 0, ret);
ENV_LEAVE(env, ip);
return (ret);
}
/*
* __txn_recover --
* ENV->txn_recover.
*
* PUBLIC: int __txn_recover __P((ENV *,
* PUBLIC: DB_PREPLIST *, long, long *, u_int32_t));
*/
int
__txn_recover(env, preplist, count, retp, flags)
ENV *env;
DB_PREPLIST *preplist;
long count, *retp;
u_int32_t flags;
{
/*
* Public API to retrieve the list of prepared, but not yet committed
* transactions. See __txn_get_prepared for details. This function
* and __db_xa_recover both wrap that one.
*/
return (__txn_get_prepared(env, NULL, preplist, count, retp, flags));
}
/*
* __txn_get_prepared --
* Returns a list of prepared (and for XA, heuristically completed)
* transactions (less than or equal to the count parameter). One of
* xids or txns must be set to point to an array of the appropriate type.
* The count parameter indicates the number of entries in the xids and/or
* txns array. The retp parameter will be set to indicate the number of
* entries returned in the xids/txns array. Flags indicates the operation,
* one of DB_FIRST or DB_NEXT.
*
* PUBLIC: int __txn_get_prepared __P((ENV *,
* PUBLIC: XID *, DB_PREPLIST *, long, long *, u_int32_t));
*/
int
__txn_get_prepared(env, xids, txns, count, retp, flags)
ENV *env;
XID *xids;
DB_PREPLIST *txns;
long count; /* This is long for XA compatibility. */
long *retp;
u_int32_t flags;
{
DB_LSN min;
DB_PREPLIST *prepp;
DB_THREAD_INFO *ip;
DB_TXNMGR *mgr;
DB_TXNREGION *region;
TXN_DETAIL *td;
XID *xidp;
long i;
int restored, ret;
*retp = 0;
MAX_LSN(min);
prepp = txns;
xidp = xids;
restored = ret = 0;
/*
* If we are starting a scan, then we traverse the active transaction
* list once making sure that all transactions are marked as not having
* been collected. Then on each pass, we mark the ones we collected
* so that if we cannot collect them all at once, we can finish up
* next time with a continue.
*/
mgr = env->tx_handle;
region = mgr->reginfo.primary;
/*
* During this pass we need to figure out if we are going to need
* to open files. We need to open files if we've never collected
* before (in which case, none of the COLLECTED bits will be set)
* and the ones that we are collecting are restored (if they aren't
* restored, then we never crashed; just the main server did).
*/
TXN_SYSTEM_LOCK(env);
/* Now begin collecting active transactions. */
for (td = SH_TAILQ_FIRST(&region->active_txn, __txn_detail);
td != NULL && *retp < count;
td = SH_TAILQ_NEXT(td, links, __txn_detail)) {
if (td->status != TXN_PREPARED ||
(flags != DB_FIRST && F_ISSET(td, TXN_DTL_COLLECTED)))
continue;
if (F_ISSET(td, TXN_DTL_RESTORED))
restored = 1;
if (xids != NULL) {
xidp->formatID = td->format;
/*
* XID structure uses longs; we use u_int32_t's as we
* log them to disk. Cast them to make the conversion
* explicit.
*/
xidp->gtrid_length = (long)td->gtrid;
xidp->bqual_length = (long)td->bqual;
memcpy(xidp->data, td->xid, sizeof(td->xid));
xidp++;
}
if (txns != NULL) {
if ((ret = __os_calloc(env,
1, sizeof(DB_TXN), &prepp->txn)) != 0) {
TXN_SYSTEM_UNLOCK(env);
goto err;
}
if ((ret = __txn_continue(env, prepp->txn, td)) != 0)
goto err;
F_SET(prepp->txn, TXN_MALLOC);
if (F_ISSET(env->dbenv, DB_ENV_TXN_NOSYNC))
F_SET(prepp->txn, TXN_NOSYNC);
else if (F_ISSET(env->dbenv, DB_ENV_TXN_WRITE_NOSYNC))
F_SET(prepp->txn, TXN_WRITE_NOSYNC);
else
F_SET(prepp->txn, TXN_SYNC);
memcpy(prepp->gid, td->xid, sizeof(td->xid));
prepp++;
}
if (!IS_ZERO_LSN(td->begin_lsn) &&
LOG_COMPARE(&td->begin_lsn, &min) < 0)
min = td->begin_lsn;
(*retp)++;
F_SET(td, TXN_DTL_COLLECTED);
}
if (flags == DB_FIRST)
for (; td != NULL; td = SH_TAILQ_NEXT(td, links, __txn_detail))
F_CLR(td, TXN_DTL_COLLECTED);
TXN_SYSTEM_UNLOCK(env);
/*
* Now link all the transactions into the transaction manager's list.
*/
if (txns != NULL && *retp != 0) {
MUTEX_LOCK(env, mgr->mutex);
for (i = 0; i < *retp; i++)
TAILQ_INSERT_TAIL(&mgr->txn_chain, txns[i].txn, links);
MUTEX_UNLOCK(env, mgr->mutex);
/*
* If we are restoring, update our count of outstanding
* transactions.
*/
if (REP_ON(env)) {
REP_SYSTEM_LOCK(env);
env->rep_handle->region->op_cnt += (u_long)*retp;
REP_SYSTEM_UNLOCK(env);
}
}
/*
* If recovery already opened the files for us, don't
* do it here.
*/
if (restored != 0 && flags == DB_FIRST &&
!F_ISSET(env->lg_handle, DBLOG_OPENFILES)) {
ENV_GET_THREAD_INFO(env, ip);
ret = __txn_openfiles(env, ip, &min, 0);
}
if (0) {
err: TXN_SYSTEM_UNLOCK(env);
}
return (ret);
}
/*
* __txn_openfiles --
* Call env_openfiles.
*
* PUBLIC: int __txn_openfiles __P((ENV *, DB_THREAD_INFO *, DB_LSN *, int));
*/
int
__txn_openfiles(env, ip, min, force)
ENV *env;
DB_THREAD_INFO *ip;
DB_LSN *min;
int force;
{
DBT data;
DB_LOGC *logc;
DB_LSN open_lsn;
DB_TXNHEAD *txninfo;
__txn_ckp_args *ckp_args;
int ret, t_ret;
/*
* Figure out the last checkpoint before the smallest
* start_lsn in the region.
*/
logc = NULL;
if ((ret = __log_cursor(env, &logc)) != 0)
goto err;
memset(&data, 0, sizeof(data));
if ((ret = __txn_getckp(env, &open_lsn)) == 0)
while (!IS_ZERO_LSN(open_lsn) && (ret =
__logc_get(logc, &open_lsn, &data, DB_SET)) == 0 &&
(force ||
(min != NULL && LOG_COMPARE(min, &open_lsn) < 0))) {
/* Format the log record. */
if ((ret = __txn_ckp_read(
env, data.data, &ckp_args)) != 0) {
__db_errx(env,
"Invalid checkpoint record at [%lu][%lu]",
(u_long)open_lsn.file,
(u_long)open_lsn.offset);
goto err;
}
/*
* If force is set, then we're forcing ourselves
* to go back far enough to open files.
* Use ckp_lsn and then break out of the loop.
*/
open_lsn = force ? ckp_args->ckp_lsn :
ckp_args->last_ckp;
__os_free(env, ckp_args);
if (force) {
if ((ret = __logc_get(logc, &open_lsn,
&data, DB_SET)) != 0)
goto err;
break;
}
}
/*
* There are several ways by which we may have gotten here.
* - We got a DB_NOTFOUND -- we need to read the first
* log record.
* - We found a checkpoint before min. We're done.
* - We found a checkpoint after min who's last_ckp is 0. We
* need to start at the beginning of the log.
* - We are forcing an openfiles and we have our ckp_lsn.
*/
if ((ret == DB_NOTFOUND || IS_ZERO_LSN(open_lsn)) && (ret =
__logc_get(logc, &open_lsn, &data, DB_FIRST)) != 0) {
__db_errx(env, "No log records");
goto err;
}
if ((ret = __db_txnlist_init(env, ip, 0, 0, NULL, &txninfo)) != 0)
goto err;
ret = __env_openfiles(
env, logc, txninfo, &data, &open_lsn, NULL, (double)0, 0);
if (txninfo != NULL)
__db_txnlist_end(env, txninfo);
err:
if (logc != NULL && (t_ret = __logc_close(logc)) != 0 && ret == 0)
ret = t_ret;
return (ret);
}