3618 Mats Kindahl 2012-02-20
WL#5223: Binary Log Group Commit
Fixes for review comments by Luis.
- Removing unecessary variables.
- Adding comments to functions.
- Simplifying an if-statement.
- Removing debug printouts that are no longer needed.
modified:
sql/binlog.cc
3617 Mats Kindahl 2012-02-20
WL#5223: Binary Log Group Commit
There were an error because when a statement was logged using
THD::binlog_query inside a stored function, it was allocated
space in the binary log, hence also queued for commit. This
committed the transaction, causing the subsequent top-level
commit to trigger an assertion inside InnoDB.
This patch solves the problem by not forcing a flush (and commit)
of the statement cache inside THD::binlog_query if called while
inside the execution of a stored function (or other stored routine).
This accumulates all the logged queries, which are then flushed to
the binary when the top-level statement commits.
modified:
sql/binlog.cc
=== modified file 'sql/binlog.cc'
--- a/sql/binlog.cc 2012-02-20 20:57:36 +0000
+++ b/sql/binlog.cc 2012-02-20 21:48:59 +0000
@@ -40,10 +40,8 @@
#include "sql_connect.h"
#include "sql_class.h"
#include "debug_sync.h"
-#include "my_atomic.h"
#include <utility>
-#include <algorithm>
using std::max;
using std::min;
@@ -116,9 +114,10 @@ private:
structure). It will set up the PSI structures and other "globals"
correctly (e.g., thread-specific variables).
- On destruction, the original thread will be re-attached
- automatically. For example, with this code, the value of current_thd
- will be the same before and after execution of the code.
+ On destruction, the original thread (which is supplied to the
+ constructor) will be re-attached automatically. For example, with
+ this code, the value of current_thd will be the same before and
+ after execution of the code.
@code
{
@@ -127,6 +126,8 @@ private:
excursion.attach_to(other_thd[i]);
}
@endcode
+
+ @note The class is not designed to be inherited from.
*/
class Thread_excursion
@@ -1044,9 +1045,7 @@ MYSQL_BIN_LOG::force_flush_stmt_cache(TH
mysql_mutex_lock(&LOCK_available);
bool do_purge = false;
- if (int err= allocate_space_in_log(thd, &do_purge))
- error= err;
- else
+ if (!(error= allocate_space_in_log(thd, &do_purge)))
{
/*
Note that we queue the thread even in the case that there is
@@ -1142,6 +1141,24 @@ static int binlog_prepare(handlerton *ht
}
+/**
+ This function is called when the binary log commit a transaction.
+
+ In the role as a transaction coordinator, the binary log will keep a
+ queue of outstanding transactions and ensure that they are committed
+ in order.
+
+ Caches are flushed and writes to the binary log queued before
+ starting to commit all outstranding transactions.
+
+ When the function returns, the session and all preceeding sessions
+ will be committed.
+
+ @param thd Session to commit.
+
+ @param all @c true if this is a real commit or a DDL commit, @c
+ false if it is a "statement commit".
+ */
int MYSQL_BIN_LOG::commit(THD *thd, bool all)
{
DBUG_ENTER("MYSQL_BIN_LOG::commit");
@@ -1149,8 +1166,12 @@ int MYSQL_BIN_LOG::commit(THD *thd, bool
binlog_cache_mngr *cache_mngr=
(binlog_cache_mngr*) thd_get_ha_data(thd, binlog_hton);
int frozen_caches = 0;
- int error= 0;
+ /*
+ Can be called from init phase, with no cache manager and hence no
+ caches. In that case, we just commit the handlertons that have
+ registered.
+ */
if (cache_mngr == NULL)
DBUG_RETURN(ha_commit_htons(thd, all));
@@ -1206,17 +1227,22 @@ int MYSQL_BIN_LOG::commit(THD *thd, bool
cache_mngr->flush(thd);
wait_and_reap(thd);
- DBUG_RETURN(error);
+ DBUG_RETURN(0);
}
+/**
+ Wait until session is committable and, if necessary, reap and commit
+ all outstanding commits.
+
+ Wait for the transaction to be complete and optionally durable (if
+ required by options). The LOCK_durable mutex also protect the commit
+ calls and reaping the binary log queue.
+
+ @param thd Session to commit.
+ */
void MYSQL_BIN_LOG::wait_and_reap(THD *thd)
{
- /*
- Wait for the transaction to be complete and optionally
- durable. The LOCK_durable mutex also protect the commit calls and
- reaping the binary log queue.
- */
wait_until_complete(thd);
Mutex_sentry durable_sentry(&LOCK_durable);
wait_until_durable(thd);
@@ -1233,7 +1259,12 @@ void MYSQL_BIN_LOG::wait_and_reap(THD *t
/**
This function is called once after each statement.
- It has the responsibility to flush the caches to the binary log on commits.
+ All flushing of caches are done inside MYSQL_BIN_LOG::commit, so
+ this function only reset some basic information.
+
+ @todo Eliminate all handlerton functions and the binlog
+ handlerton. Instead move all the functionality into TC_LOG and
+ subclasses (including MYSQL_BIN_LOG).
@param hton The binlog handlerton.
@param thd The client thread that executes the transaction.
@@ -1241,6 +1272,7 @@ void MYSQL_BIN_LOG::wait_and_reap(THD *t
@false otherwise.
@see handlerton::commit
+ @see MYSQL_BIN_LOG::commit
*/
static int binlog_commit(handlerton *hton, THD *thd, bool all)
{
@@ -1248,17 +1280,6 @@ static int binlog_commit(handlerton *hto
binlog_cache_mngr *const cache_mngr=
(binlog_cache_mngr*) thd_get_ha_data(thd, binlog_hton);
- DBUG_PRINT("debug",
- ("all: %s, all.empty: %s, stmt.empty: %s, in_transaction: %s",
- YESNO(all),
- YESNO(thd->transaction.all.is_empty()),
- YESNO(thd->transaction.stmt.is_empty()),
- YESNO(thd->in_multi_stmt_transaction_mode())));
- DBUG_PRINT("debug",
- ("all.cannot_safely_rollback(): %s, stmt.cannot_safely_rollback(): %s",
- YESNO(thd->transaction.all.cannot_safely_rollback()),
- YESNO(thd->transaction.stmt.cannot_safely_rollback())));
-
if (all)
{
cache_mngr->trx_cache.reset();
@@ -2644,7 +2665,8 @@ int MYSQL_BIN_LOG::raw_get_current_log(L
mysql_mutex_assert_owner(&LOCK_log);
linfo->complete_pos = last_complete;
/*
- I would like to have this assertion here, but
+ I would like to have this assertion here, but it seems
+ LOCK_durable is not always locked. See show_binlogs().
*/
// mysql_mutex_assert_owner(&LOCK_durable);
linfo->durable_pos = last_durable;
No bundle (reason: useless for push emails).
| Thread |
|---|
| • bzr push into mysql-trunk branch (mats.kindahl:3617 to 3618) WL#5223 | Mats Kindahl | 21 Feb |
