diff options
Diffstat (limited to 'storage/maria/ma_commit.c')
| -rw-r--r-- | storage/maria/ma_commit.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/storage/maria/ma_commit.c b/storage/maria/ma_commit.c new file mode 100644 index 00000000000..951de1beeff --- /dev/null +++ b/storage/maria/ma_commit.c @@ -0,0 +1,125 @@ +/* Copyright (C) 2007 MySQL AB + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + +#include "maria_def.h" +#include "trnman.h" + +/** + @brief writes a COMMIT record to log and commits transaction in memory + + @param trn transaction + + @return Operation status + @retval 0 ok + @retval 1 error (disk error or out of memory) +*/ + +int ma_commit(TRN *trn) +{ + int res; + LSN commit_lsn; + LEX_CUSTRING log_array[TRANSLOG_INTERNAL_PARTS]; + DBUG_ENTER("ma_commit"); + + DBUG_ASSERT(trn->rec_lsn == LSN_IMPOSSIBLE); + if (trn->undo_lsn == 0) /* no work done, rollback (cheaper than commit) */ + DBUG_RETURN(trnman_rollback_trn(trn)); + /* + - if COMMIT record is written before trnman_commit_trn(): + if Checkpoint comes in the middle it will see trn is not committed, + then if crash, Recovery might roll back trn (if min(rec_lsn) is after + COMMIT record) and this is not an issue as + * transaction's updates were not made visible to other transactions + * "commit ok" was not sent to client + Alternatively, Recovery might commit trn (if min(rec_lsn) is before COMMIT + record), which is ok too. All in all it means that "trn committed" is not + 100% equal to "COMMIT record written". + - if COMMIT record is written after trnman_commit_trn(): + if crash happens between the two, trn will be rolled back which is an + issue (transaction's updates were made visible to other transactions). + So we need to go the first way. + + Note that we have to use | here to ensure that all calls are made. + */ + + /* + We do not store "thd->transaction.xid_state.xid" for now, it will be + needed only when we support XA. + */ + res= (translog_write_record(&commit_lsn, LOGREC_COMMIT, + trn, NULL, 0, + sizeof(log_array)/sizeof(log_array[0]), + log_array, NULL, NULL) | + translog_flush(commit_lsn)); + + DBUG_EXECUTE_IF("maria_sleep_in_commit", + { + DBUG_PRINT("info", ("maria_sleep_in_commit")); + sleep(3); + }); + res|= trnman_commit_trn(trn); + + + /* + Note: if trnman_commit_trn() fails above, we have already + written the COMMIT record, so Checkpoint and Recovery will see the + transaction as committed. + */ + DBUG_RETURN(res); +} + + +/** + @brief Writes a COMMIT record for a transaciton associated with a file + + @param info Maria handler + + @return Operation status + @retval 0 ok + @retval # error (disk error or out of memory) +*/ + +int maria_commit(MARIA_HA *info) +{ + return info->s->now_transactional ? ma_commit(info->trn) : 0; +} + + +/** + @brief Starts a transaction on a file handle + + @param info Maria handler + + @return Operation status + @retval 0 ok + @retval # Error code. +*/ + +int maria_begin(MARIA_HA *info) +{ + DBUG_ENTER("maria_begin"); + + if (info->s->now_transactional) + { + TRN *trn= trnman_new_trn(0); + if (unlikely(!trn)) + DBUG_RETURN(HA_ERR_OUT_OF_MEM); + + DBUG_PRINT("info", ("TRN set to 0x%lx", (ulong) trn)); + _ma_set_trn_for_table(info, trn); + } + DBUG_RETURN(0); +} + |