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-rw-r--r--db/txn/txn.c869
1 files changed, 869 insertions, 0 deletions
diff --git a/db/txn/txn.c b/db/txn/txn.c
new file mode 100644
index 000000000..0f6d894c1
--- /dev/null
+++ b/db/txn/txn.c
@@ -0,0 +1,869 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996, 1997, 1998, 1999, 2000
+ * 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. 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 "db_config.h"
+
+#ifndef lint
+static const char revid[] = "$Id: txn.c,v 11.61 2001/01/10 18:18:52 bostic Exp $";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+
+#if TIME_WITH_SYS_TIME
+#include <sys/time.h>
+#include <time.h>
+#else
+#if HAVE_SYS_TIME_H
+#include <sys/time.h>
+#else
+#include <time.h>
+#endif
+#endif
+
+#include <string.h>
+#endif
+
+#ifdef HAVE_RPC
+#include "db_server.h"
+#endif
+
+#include "db_int.h"
+#include "db_shash.h"
+#include "txn.h"
+#include "lock.h"
+#include "log.h"
+#include "db_dispatch.h"
+#include "db_page.h"
+#include "db_ext.h"
+
+#ifdef HAVE_RPC
+#include "gen_client_ext.h"
+#include "rpc_client_ext.h"
+#endif
+
+static int __txn_begin __P((DB_TXN *));
+static int __txn_isvalid __P((const DB_TXN *, TXN_DETAIL **, u_int32_t));
+static int __txn_undo __P((DB_TXN *));
+
+/*
+ * 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(dbenv, parent, txnpp, flags)
+ DB_ENV *dbenv;
+ DB_TXN *parent, **txnpp;
+ u_int32_t flags;
+{
+ DB_TXN *txn;
+ int ret;
+
+#ifdef HAVE_RPC
+ if (F_ISSET(dbenv, DB_ENV_RPCCLIENT))
+ return (__dbcl_txn_begin(dbenv, parent, txnpp, flags));
+#endif
+
+ PANIC_CHECK(dbenv);
+ ENV_REQUIRES_CONFIG(dbenv, dbenv->tx_handle, DB_INIT_TXN);
+
+ if ((ret = __db_fchk(dbenv,
+ "txn_begin", flags,
+ DB_TXN_NOWAIT | DB_TXN_NOSYNC | DB_TXN_SYNC)) != 0)
+ return (ret);
+ if ((ret = __db_fcchk(dbenv,
+ "txn_begin", flags, DB_TXN_NOSYNC, DB_TXN_SYNC)) != 0)
+ return (ret);
+
+ if ((ret = __os_calloc(dbenv, 1, sizeof(DB_TXN), &txn)) != 0)
+ return (ret);
+
+ txn->mgrp = dbenv->tx_handle;
+ txn->parent = parent;
+ TAILQ_INIT(&txn->kids);
+ txn->flags = TXN_MALLOC;
+ if (LF_ISSET(DB_TXN_NOSYNC))
+ F_SET(txn, TXN_NOSYNC);
+ if (LF_ISSET(DB_TXN_SYNC))
+ F_SET(txn, TXN_SYNC);
+ if (LF_ISSET(DB_TXN_NOWAIT))
+ F_SET(txn, TXN_NOWAIT);
+
+ 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;
+{
+ PANIC_CHECK(dbenv);
+
+ memset(txn, 0, sizeof(DB_TXN));
+
+ txn->mgrp = dbenv->tx_handle;
+
+ return (__txn_begin(txn));
+}
+
+/*
+ * __txn_begin --
+ * Normal DB version of txn_begin.
+ */
+static int
+__txn_begin(txn)
+ DB_TXN *txn;
+{
+ DB_ENV *dbenv;
+ DB_LSN begin_lsn;
+ DB_TXNMGR *mgr;
+ DB_TXNREGION *region;
+ TXN_DETAIL *td;
+ size_t off;
+ u_int32_t id;
+ int ret;
+
+ mgr = txn->mgrp;
+ dbenv = mgr->dbenv;
+ region = mgr->reginfo.primary;
+
+ /*
+ * 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 (LOGGING_ON(dbenv) &&
+ (ret = log_put(dbenv, &begin_lsn, NULL, DB_CURLSN)) != 0)
+ goto err2;
+
+ R_LOCK(dbenv, &mgr->reginfo);
+
+ /* Make sure that last_txnid is not going to wrap around. */
+ if (region->last_txnid == TXN_INVALID) {
+ __db_err(dbenv,
+"txn_begin: transaction ID wrapped. Exit the database environment\nand restart the application as if application failure had occurred");
+ ret = EINVAL;
+ goto err1;
+ }
+
+ /* Allocate a new transaction detail structure. */
+ if ((ret =
+ __db_shalloc(mgr->reginfo.addr, sizeof(TXN_DETAIL), 0, &td)) != 0) {
+ __db_err(dbenv,
+ "Unable to allocate memory for transaction detail");
+ goto err1;
+ }
+
+ /* Place transaction on active transaction list. */
+ SH_TAILQ_INSERT_HEAD(&region->active_txn, td, links, __txn_detail);
+
+ id = ++region->last_txnid;
+ ++region->nbegins;
+ if (++region->nactive > region->maxnactive)
+ region->maxnactive = region->nactive;
+
+ td->txnid = id;
+ td->begin_lsn = begin_lsn;
+ ZERO_LSN(td->last_lsn);
+ td->status = TXN_RUNNING;
+ if (txn->parent != NULL)
+ td->parent = txn->parent->off;
+ else
+ td->parent = INVALID_ROFF;
+
+ off = R_OFFSET(&mgr->reginfo, td);
+ R_UNLOCK(dbenv, &mgr->reginfo);
+
+ ZERO_LSN(txn->last_lsn);
+ txn->txnid = id;
+ txn->off = off;
+
+ /*
+ * If this is a transaction family, we must link the child to the
+ * maximal grandparent in the lock table for deadlock detection.
+ */
+ if (txn->parent != NULL && LOCKING_ON(dbenv))
+ if ((ret = __lock_addfamilylocker(dbenv,
+ txn->parent->txnid, txn->txnid)) != 0)
+ goto err2;
+
+ if (F_ISSET(txn, TXN_MALLOC)) {
+ MUTEX_THREAD_LOCK(dbenv, mgr->mutexp);
+ TAILQ_INSERT_TAIL(&mgr->txn_chain, txn, links);
+ MUTEX_THREAD_UNLOCK(dbenv, mgr->mutexp);
+ }
+
+ return (0);
+
+err1: R_UNLOCK(dbenv, &mgr->reginfo);
+
+err2: return (ret);
+}
+
+/*
+ * txn_commit --
+ * Commit a transaction.
+ */
+int
+txn_commit(txnp, flags)
+ DB_TXN *txnp;
+ u_int32_t flags;
+{
+ DB_ENV *dbenv;
+ DB_TXN *kid;
+ int is_commit, ret, t_ret;
+
+ dbenv = txnp->mgrp->dbenv;
+
+#ifdef HAVE_RPC
+ if (F_ISSET(dbenv, DB_ENV_RPCCLIENT))
+ return (__dbcl_txn_commit(txnp, flags));
+#endif
+
+ PANIC_CHECK(dbenv);
+
+ if ((ret = __txn_isvalid(txnp, NULL, TXN_COMMITTED)) != 0)
+ return (ret);
+
+ /*
+ * We clear flags that are incorrect, ignoring any flag errors, and
+ * default to synchronous operations. By definition, transaction
+ * handles are dead when we return, and this error should never
+ * happen, but we don't want to fail in the field 'cause the app is
+ * specifying the wrong flag for some reason.
+ */
+ if (__db_fchk(dbenv,
+ "txn_commit", flags, DB_TXN_NOSYNC | DB_TXN_SYNC) != 0)
+ flags = DB_TXN_SYNC;
+ if (__db_fcchk(dbenv,
+ "txn_commit", flags, DB_TXN_NOSYNC, DB_TXN_SYNC) != 0)
+ flags = DB_TXN_SYNC;
+ if (LF_ISSET(DB_TXN_NOSYNC)) {
+ F_CLR(txnp, TXN_SYNC);
+ F_SET(txnp, TXN_NOSYNC);
+ }
+ if (LF_ISSET(DB_TXN_SYNC)) {
+ F_CLR(txnp, TXN_NOSYNC);
+ F_SET(txnp, TXN_SYNC);
+ }
+
+ /*
+ * Commit any unresolved children. If there's an error, abort any
+ * unresolved children and the parent.
+ */
+ while ((kid = TAILQ_FIRST(&txnp->kids)) != NULL)
+ if ((ret = txn_commit(kid, flags)) != 0) {
+ while ((kid = TAILQ_FIRST(&txnp->kids)) != NULL)
+ (void)txn_abort(kid);
+ (void)txn_abort(txnp);
+ goto err;
+ }
+
+ /*
+ * 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 it may still
+ * abort (if its parent aborts), and otherwise its parent or ultimate
+ * ancestor will write synchronously.
+ *
+ * I'd rather return a logging error than a flag-wrong error, so if
+ * the log routines fail, set "ret" without regard to previous value.
+ */
+ if (LOGGING_ON(dbenv) && !IS_ZERO_LSN(txnp->last_lsn)) {
+ if (txnp->parent == NULL) {
+ if ((t_ret = __txn_regop_log(dbenv,
+ txnp, &txnp->last_lsn,
+ (F_ISSET(dbenv, DB_ENV_TXN_NOSYNC) &&
+ !F_ISSET(txnp, TXN_SYNC)) ||
+ F_ISSET(txnp, TXN_NOSYNC) ? 0 : DB_FLUSH,
+ TXN_COMMIT, (int32_t)time(NULL))) != 0) {
+ ret = t_ret;
+ goto err;
+ }
+ } else {
+ /* Log the commit in the parent! */
+ if ((t_ret = __txn_child_log(dbenv,
+ txnp->parent, &txnp->parent->last_lsn,
+ 0, txnp->txnid, &txnp->last_lsn)) != 0) {
+ ret = t_ret;
+ goto err;
+ }
+
+ F_SET(txnp->parent, TXN_CHILDCOMMIT);
+ }
+ }
+
+ is_commit = 1;
+ if (0) {
+err: is_commit = 0;
+ }
+ if ((t_ret = __txn_end(txnp, is_commit)) != 0 && ret == 0)
+ ret = t_ret;
+ return (ret);
+}
+
+/*
+ * txn_abort --
+ * Abort a transaction.
+ */
+int
+txn_abort(txnp)
+ DB_TXN *txnp;
+{
+ DB_ENV *dbenv;
+ DB_TXN *kid;
+ int ret, t_ret;
+
+ dbenv = txnp->mgrp->dbenv;
+
+#ifdef HAVE_RPC
+ if (F_ISSET(dbenv, DB_ENV_RPCCLIENT))
+ return (__dbcl_txn_abort(txnp));
+#endif
+
+ PANIC_CHECK(dbenv);
+
+ if ((ret = __txn_isvalid(txnp, NULL, TXN_ABORTED)) != 0)
+ return (ret);
+
+ /* Abort any unresolved children. */
+ while ((kid = TAILQ_FIRST(&txnp->kids)) != NULL)
+ if ((t_ret = txn_abort(kid)) != 0 && ret == 0)
+ ret = t_ret;
+
+ if ((t_ret = __txn_undo(txnp)) != 0 && ret == 0)
+ ret = t_ret;
+
+ if ((t_ret = __txn_end(txnp, 0)) != 0 && ret == 0)
+ ret = t_ret;
+ return (ret);
+}
+
+/*
+ * 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;
+ DB_TXN *kid;
+ TXN_DETAIL *td;
+ int ret;
+
+ dbenv = txnp->mgrp->dbenv;
+
+#ifdef HAVE_RPC
+ if (F_ISSET(dbenv, DB_ENV_RPCCLIENT))
+ return (__dbcl_txn_prepare(txnp));
+#endif
+
+ PANIC_CHECK(dbenv);
+
+ if ((ret = __txn_isvalid(txnp, &td, TXN_PREPARED)) != 0)
+ return (ret);
+
+ /* Prepare any unresolved children. */
+ while ((kid = TAILQ_FIRST(&txnp->kids)) != NULL)
+ if ((ret = txn_prepare(kid)) != 0)
+ return (ret);
+
+ /*
+ * 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.
+ */
+
+ if (LOGGING_ON(dbenv)) {
+ memset(&xid, 0, sizeof(xid));
+ xid.data = td->xid;
+ xid.size = td->xa_status != TXN_XA_ENDED &&
+ td->xa_status != TXN_XA_SUSPENDED ? 0 : sizeof(td->xid);
+ if ((ret = __txn_xa_regop_log(dbenv, txnp, &txnp->last_lsn,
+ (F_ISSET(dbenv, DB_ENV_TXN_NOSYNC) &&
+ !F_ISSET(txnp, TXN_SYNC)) ||
+ F_ISSET(txnp, 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",
+ db_strerror(ret));
+ return (ret);
+ }
+ if (txnp->parent != NULL)
+ F_SET(txnp->parent, TXN_CHILDCOMMIT);
+ }
+
+ MUTEX_THREAD_LOCK(dbenv, txnp->mgrp->mutexp);
+ td->status = TXN_PREPARED;
+ MUTEX_THREAD_UNLOCK(dbenv, txnp->mgrp->mutexp);
+ return (0);
+}
+
+/*
+ * txn_id --
+ * Return the transaction ID.
+ */
+u_int32_t
+txn_id(txnp)
+ DB_TXN *txnp;
+{
+ return (txnp->txnid);
+}
+
+/*
+ * __txn_isvalid --
+ * Return 0 if the txnp is reasonable, otherwise panic.
+ */
+static int
+__txn_isvalid(txnp, tdp, op)
+ const DB_TXN *txnp;
+ TXN_DETAIL **tdp;
+ u_int32_t op;
+{
+ DB_TXNMGR *mgrp;
+ TXN_DETAIL *tp;
+
+ mgrp = txnp->mgrp;
+
+ /* Check for live cursors. */
+ if (txnp->cursors != 0) {
+ __db_err(mgrp->dbenv, "transaction has active cursors");
+ goto err;
+ }
+
+ /* Check transaction's status. */
+ tp = (TXN_DETAIL *)R_ADDR(&mgrp->reginfo, txnp->off);
+ if (tdp != NULL)
+ *tdp = tp;
+
+ switch (tp->status) {
+ case TXN_ABORTED:
+ case TXN_COMMITTED:
+ default:
+ __db_err(mgrp->dbenv, "transaction already %s",
+ tp->status == TXN_COMMITTED ? "committed" : "aborted");
+ goto err;
+ case TXN_PREPARED:
+ if (op == TXN_PREPARED) {
+ __db_err(mgrp->dbenv, "transaction already prepared");
+ goto err;
+ }
+ case TXN_RUNNING:
+ break;
+ }
+
+ return (0);
+
+err: /*
+ * If there's a serious problem with the transaction, panic. TXN
+ * handles are dead by definition when we return, and if you use
+ * a cursor you forgot to close, we have no idea what will happen.
+ */
+ return (__db_panic(mgrp->dbenv, EINVAL));
+}
+
+/*
+ * __txn_end --
+ * Internal transaction end routine.
+ *
+ * PUBLIC: int __txn_end __P((DB_TXN *, int));
+ */
+int
+__txn_end(txnp, is_commit)
+ DB_TXN *txnp;
+ int is_commit;
+{
+ DB_ENV *dbenv;
+ DB_LOCKREQ request;
+ DB_TXNMGR *mgr;
+ DB_TXNREGION *region;
+ TXN_DETAIL *tp;
+ int ret;
+
+ mgr = txnp->mgrp;
+ dbenv = mgr->dbenv;
+ region = mgr->reginfo.primary;
+
+ /* Release the locks. */
+ request.op = txnp->parent == NULL ||
+ is_commit == 0 ? DB_LOCK_PUT_ALL : DB_LOCK_INHERIT;
+
+ if (LOCKING_ON(dbenv)) {
+ ret = lock_vec(dbenv, txnp->txnid, 0, &request, 1, NULL);
+ if (ret != 0 && (ret != DB_LOCK_DEADLOCK || is_commit)) {
+ __db_err(dbenv, "%s: release locks failed %s",
+ is_commit ? "txn_commit" : "txn_abort",
+ db_strerror(ret));
+ __db_panic(dbenv, ret);
+ }
+ }
+
+ /* End the transaction. */
+ R_LOCK(dbenv, &mgr->reginfo);
+
+ tp = (TXN_DETAIL *)R_ADDR(&mgr->reginfo, txnp->off);
+ SH_TAILQ_REMOVE(&region->active_txn, tp, links, __txn_detail);
+ __db_shalloc_free(mgr->reginfo.addr, tp);
+
+ if (is_commit)
+ region->ncommits++;
+ else
+ region->naborts++;
+ --region->nactive;
+
+ R_UNLOCK(dbenv, &mgr->reginfo);
+
+ /*
+ * The transaction cannot get more locks, remove its locker info.
+ */
+ if (LOCKING_ON(dbenv))
+ __lock_freefamilylocker(dbenv->lk_handle, txnp->txnid);
+ if (txnp->parent != NULL)
+ TAILQ_REMOVE(&txnp->parent->kids, txnp, klinks);
+
+ /* Free the space. */
+ if (F_ISSET(txnp, TXN_MALLOC)) {
+ MUTEX_THREAD_LOCK(dbenv, mgr->mutexp);
+ TAILQ_REMOVE(&mgr->txn_chain, txnp, links);
+ MUTEX_THREAD_UNLOCK(dbenv, mgr->mutexp);
+
+ __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_ENV *dbenv;
+ DB_LSN key_lsn;
+ DB_TXNMGR *mgr;
+ void *txnlist;
+ int ret, threaded;
+
+ mgr = txnp->mgrp;
+ dbenv = mgr->dbenv;
+ txnlist = NULL;
+
+ if (!LOGGING_ON(dbenv))
+ 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));
+ threaded = F_ISSET(dbenv, DB_ENV_THREAD) ? 1 : 0;
+ if (threaded)
+ F_SET(&rdbt, DB_DBT_MALLOC);
+
+ key_lsn = txnp->last_lsn;
+
+ /* Allocate a transaction list for children or aborted page creates. */
+ if ((ret = __db_txnlist_init(dbenv, &txnlist)) != 0)
+ return (ret);
+
+ if (F_ISSET(txnp, TXN_CHILDCOMMIT) &&
+ (ret = __db_txnlist_lsninit(dbenv,
+ txnlist, &txnp->last_lsn)) != 0)
+ return (ret);
+
+ 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(dbenv, &key_lsn, &rdbt, DB_SET)) == 0) {
+ ret = __db_dispatch(dbenv,
+ &rdbt, &key_lsn, DB_TXN_ABORT, txnlist);
+ if (threaded && rdbt.data != NULL) {
+ __os_free(rdbt.data, rdbt.size);
+ rdbt.data = NULL;
+ }
+ if (F_ISSET(txnp, TXN_CHILDCOMMIT))
+ (void)__db_txnlist_lsnadd(dbenv,
+ txnlist, &key_lsn, 0);
+ }
+ if (ret != 0) {
+ __db_err(txnp->mgrp->dbenv,
+ "txn_abort: Log undo failed for LSN: %lu %lu: %s",
+ (u_long)key_lsn.file, (u_long)key_lsn.offset,
+ db_strerror(ret));
+ if (txnlist != NULL)
+ __db_txnlist_end(dbenv, txnlist);
+ return (ret);
+ }
+ }
+
+ if (txnlist != NULL) {
+ __db_do_the_limbo(dbenv, txnlist);
+ __db_txnlist_end(dbenv, txnlist);
+ }
+
+ 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(dbenv, kbytes, minutes, flags)
+ DB_ENV *dbenv;
+ u_int32_t kbytes, minutes, flags;
+{
+ DB_LOG *dblp;
+ DB_LSN ckp_lsn, sync_lsn, last_ckp;
+ DB_TXNMGR *mgr;
+ DB_TXNREGION *region;
+ LOG *lp;
+ TXN_DETAIL *txnp;
+ time_t last_ckp_time, now;
+ u_int32_t bytes, mbytes;
+ int interval, ret;
+
+#ifdef HAVE_RPC
+ if (F_ISSET(dbenv, DB_ENV_RPCCLIENT))
+ return (__dbcl_txn_checkpoint(dbenv, kbytes, minutes));
+#endif
+ PANIC_CHECK(dbenv);
+ ENV_REQUIRES_CONFIG(dbenv, dbenv->tx_handle, DB_INIT_TXN);
+
+ mgr = dbenv->tx_handle;
+ region = mgr->reginfo.primary;
+ dblp = dbenv->lg_handle;
+ lp = dblp->reginfo.primary;
+
+ /*
+ * Check if we need to checkpoint.
+ */
+ ZERO_LSN(ckp_lsn);
+
+ if (LF_ISSET(DB_FORCE))
+ goto do_ckp;
+
+ R_LOCK(dbenv, &dblp->reginfo);
+ mbytes = lp->stat.st_wc_mbytes;
+ /*
+ * We add the current buffer offset so as to count bytes that
+ * have not yet been written, but are sitting in the log buffer.
+ */
+ bytes = lp->stat.st_wc_bytes + lp->b_off;
+ ckp_lsn = lp->lsn;
+ R_UNLOCK(dbenv, &dblp->reginfo);
+
+ /* Don't checkpoint a quiescent database. */
+ if (bytes == 0 && mbytes == 0)
+ return (0);
+
+ if (kbytes != 0 && mbytes * 1024 + bytes / 1024 >= (u_int32_t)kbytes)
+ goto do_ckp;
+
+ if (minutes != 0) {
+ (void)time(&now);
+
+ R_LOCK(dbenv, &mgr->reginfo);
+ last_ckp_time = region->time_ckp;
+ R_UNLOCK(dbenv, &mgr->reginfo);
+
+ if (now - last_ckp_time >= (time_t)(minutes * 60))
+ 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)) {
+ R_LOCK(dbenv, &dblp->reginfo);
+ ckp_lsn = lp->lsn;
+ R_UNLOCK(dbenv, &dblp->reginfo);
+ }
+
+ /*
+ * We have to find an LSN such that all transactions begun
+ * before that LSN are complete.
+ */
+ R_LOCK(dbenv, &mgr->reginfo);
+
+ if (IS_ZERO_LSN(region->pending_ckp)) {
+ for (txnp =
+ SH_TAILQ_FIRST(&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;
+ }
+ region->pending_ckp = ckp_lsn;
+ } else
+ ckp_lsn = region->pending_ckp;
+
+ R_UNLOCK(dbenv, &mgr->reginfo);
+
+ /*
+ * Try three times to sync the mpool buffers up to the specified LSN,
+ * sleeping 1, 2 and 4 seconds between attempts.
+ */
+ if (MPOOL_ON(dbenv))
+ for (interval = 1;;) {
+ /*
+ * memp_sync may change the lsn you pass it, so don't
+ * pass it the actual ckp_lsn, pass it a local instead.
+ */
+ sync_lsn = ckp_lsn;
+ if ((ret = memp_sync(dbenv, &sync_lsn)) == 0)
+ break;
+
+ /*
+ * ret == DB_INCOMPLETE means there are still buffers
+ * to flush, the checkpoint is not complete.
+ */
+ if (ret == DB_INCOMPLETE) {
+ if (interval > 4)
+ return (ret);
+
+ (void)__os_sleep(dbenv, interval, 0);
+ interval *= 2;
+ } else {
+ __db_err(dbenv,
+ "txn_checkpoint: failure in memp_sync %s",
+ db_strerror(ret));
+ return (ret);
+ }
+ }
+
+ if (LOGGING_ON(dbenv)) {
+ R_LOCK(dbenv, &mgr->reginfo);
+ last_ckp = region->last_ckp;
+ ZERO_LSN(region->pending_ckp);
+ R_UNLOCK(dbenv, &mgr->reginfo);
+
+ if ((ret = __txn_ckp_log(dbenv,
+ NULL, &ckp_lsn, DB_CHECKPOINT, &ckp_lsn,
+ &last_ckp, (int32_t)time(NULL))) != 0) {
+ __db_err(dbenv,
+ "txn_checkpoint: log failed at LSN [%ld %ld] %s",
+ (long)ckp_lsn.file, (long)ckp_lsn.offset,
+ db_strerror(ret));
+ return (ret);
+ }
+
+ R_LOCK(dbenv, &mgr->reginfo);
+ region->last_ckp = ckp_lsn;
+ (void)time(&region->time_ckp);
+ R_UNLOCK(dbenv, &mgr->reginfo);
+ }
+ return (0);
+}
+
+/*
+ * __txn_activekids --
+ * Return if this transaction has any active children.
+ *
+ * PUBLIC: int __txn_activekids __P((DB_ENV *, u_int32_t, DB_TXN *));
+ */
+int
+__txn_activekids(dbenv, rectype, txnp)
+ DB_ENV *dbenv;
+ u_int32_t rectype;
+ DB_TXN *txnp;
+{
+ /*
+ * On a child commit, we know that there are children (i.e., the
+ * commiting child at the least. In that case, skip this check.
+ */
+ if (rectype == DB_txn_child)
+ return (0);
+
+ if (TAILQ_FIRST(&txnp->kids) != NULL) {
+ __db_err(dbenv, "Child transaction is active");
+ return (EPERM);
+ }
+ return (0);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-30 14:55:10 +0000