diff options
Diffstat (limited to 'innobase/trx/trx0trx.c')
| -rw-r--r-- | innobase/trx/trx0trx.c | 118 |
1 files changed, 87 insertions, 31 deletions
diff --git a/innobase/trx/trx0trx.c b/innobase/trx/trx0trx.c index 5753b5b338e..1ece349ec6c 100644 --- a/innobase/trx/trx0trx.c +++ b/innobase/trx/trx0trx.c @@ -86,6 +86,10 @@ trx_create( trx->start_time = time(NULL); trx->isolation_level = TRX_ISO_REPEATABLE_READ; + + trx->id = ut_dulint_zero; + trx->no = ut_dulint_max; + trx->check_foreigns = TRUE; trx->check_unique_secondary = TRUE; @@ -135,6 +139,8 @@ trx_create( trx->lock_heap = mem_heap_create_in_buffer(256); UT_LIST_INIT(trx->trx_locks); + UT_LIST_INIT(trx->trx_savepoints); + trx->dict_operation_lock_mode = 0; trx->has_search_latch = FALSE; trx->search_latch_timeout = BTR_SEA_TIMEOUT; @@ -776,29 +782,53 @@ trx_commit_off_kernel( efficient here: call os_thread_yield here to allow also other trxs to come to commit! */ - /* We now flush the log, as the transaction made changes to - the database, making the transaction committed on disk. It is - enough that any one of the log groups gets written to disk. */ - /*-------------------------------------*/ - /* Most MySQL users run with srv_flush_.. set to 0: */ - - if (srv_flush_log_at_trx_commit != 0) { - if (srv_unix_file_flush_method != SRV_UNIX_NOSYNC - && srv_flush_log_at_trx_commit != 2 - && !trx->flush_log_later) { - - /* Write the log to the log files AND flush - them to disk */ - - log_write_up_to(lsn, LOG_WAIT_ONE_GROUP, TRUE); - } else { - /* Write the log but do not flush it to disk */ - - log_write_up_to(lsn, LOG_WAIT_ONE_GROUP, FALSE); - } - } + /* Depending on the my.cnf options, we may now write the log + buffer to the log files, making the transaction durable if + the OS does not crash. We may also flush the log files to + disk, making the transaction durable also at an OS crash or a + power outage. + + The idea in InnoDB's group commit is that a group of + transactions gather behind a trx doing a physical disk write + to log files, and when that physical write has been completed, + one of those transactions does a write which commits the whole + group. Note that this group commit will only bring benefit if + there are > 2 users in the database. Then at least 2 users can + gather behind one doing the physical log write to disk. + + If we are calling trx_commit() under MySQL's binlog mutex, we + will delay possible log write and flush to a separate function + trx_commit_complete_for_mysql(), which is only called when the + thread has released the binlog mutex. This is to make the + group commit algorithm to work. Otherwise, the MySQL binlog + mutex would serialize all commits and prevent a group of + transactions from gathering. */ + + if (trx->flush_log_later) { + /* Do nothing yet */ + } else if (srv_flush_log_at_trx_commit == 0) { + /* Do nothing */ + } else if (srv_flush_log_at_trx_commit == 1) { + if (srv_unix_file_flush_method == SRV_UNIX_NOSYNC) { + /* Write the log but do not flush it to disk */ + + log_write_up_to(lsn, LOG_WAIT_ONE_GROUP, FALSE); + } else { + /* Write the log to the log files AND flush + them to disk */ + + log_write_up_to(lsn, LOG_WAIT_ONE_GROUP, TRUE); + } + } else if (srv_flush_log_at_trx_commit == 2) { + + /* Write the log but do not flush it to disk */ + + log_write_up_to(lsn, LOG_WAIT_ONE_GROUP, FALSE); + } else { + ut_a(0); + } trx->commit_lsn = lsn; @@ -807,6 +837,9 @@ trx_commit_off_kernel( mutex_enter(&kernel_mutex); } + /* Free savepoints */ + trx_roll_savepoints_free(trx, NULL); + trx->conc_state = TRX_NOT_STARTED; trx->rseg = NULL; trx->undo_no = ut_dulint_zero; @@ -1492,21 +1525,37 @@ trx_commit_complete_for_mysql( /* out: 0 or error number */ trx_t* trx) /* in: trx handle */ { - ut_a(trx); + dulint lsn = trx->commit_lsn; + + ut_a(trx); + + trx->op_info = (char*)"flushing log"; - if (srv_flush_log_at_trx_commit == 1 - && srv_unix_file_flush_method != SRV_UNIX_NOSYNC) { - - trx->op_info = (char *) "flushing log"; + if (srv_flush_log_at_trx_commit == 0) { + /* Do nothing */ + } else if (srv_flush_log_at_trx_commit == 1) { + if (srv_unix_file_flush_method == SRV_UNIX_NOSYNC) { + /* Write the log but do not flush it to disk */ - /* Flush the log files to disk */ + log_write_up_to(lsn, LOG_WAIT_ONE_GROUP, FALSE); + } else { + /* Write the log to the log files AND flush them to + disk */ - log_write_up_to(trx->commit_lsn, LOG_WAIT_ONE_GROUP, TRUE); + log_write_up_to(lsn, LOG_WAIT_ONE_GROUP, TRUE); + } + } else if (srv_flush_log_at_trx_commit == 2) { - trx->op_info = (char *) ""; - } + /* Write the log but do not flush it to disk */ - return(0); + log_write_up_to(lsn, LOG_WAIT_ONE_GROUP, FALSE); + } else { + ut_a(0); + } + + trx->op_info = (char*)""; + + return(0); } /************************************************************************** @@ -1575,6 +1624,13 @@ trx_print( } buf += sprintf(buf, "\n"); + + if (trx->n_mysql_tables_in_use > 0 || trx->mysql_n_tables_locked > 0) { + + buf += sprintf(buf, "mysql tables in use %lu, locked %lu\n", + trx->n_mysql_tables_in_use, + trx->mysql_n_tables_locked); + } start_of_line = buf; |