Allocate Transaction_state_tracker statically

One less new/delete per connection. Part of MDEV-14984 - regression in connect performance

Author: svoj

sql/lock.cc

@@ -252,16 +252,11 @@ static void track_table_access(THD *thd, TABLE **tables, size_t count)
 {
  if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
  {
- Transaction_state_tracker *tst= (Transaction_state_tracker *)
- thd->session_tracker.get_tracker(TRANSACTION_INFO_TRACKER);
-
  while (count--)
  {
- TABLE *t= tables[count];
-
- if (t)
- tst->add_trx_state(thd, t->reginfo.lock_type,
- t->file->has_transaction_manager());
+ if (TABLE *t= tables[count])
+ thd->session_tracker.transaction_info.add_trx_state(thd,
+ t->reginfo.lock_type, t->file->has_transaction_manager());
  }
  }
 }

sql/session_tracker.cc

@@ -1345,7 +1345,7 @@ Session_tracker::Session_tracker()
  m_trackers[SESSION_SYSVARS_TRACKER]= 0;
  m_trackers[CURRENT_SCHEMA_TRACKER]= &current_schema;
  m_trackers[SESSION_STATE_CHANGE_TRACKER]= &state_change;
- m_trackers[TRANSACTION_INFO_TRACKER]= 0;
+ m_trackers[TRANSACTION_INFO_TRACKER]= &transaction_info;
 }
 
 
@@ -1367,8 +1367,6 @@ void Session_tracker::enable(THD *thd)
  deinit();
  m_trackers[SESSION_SYSVARS_TRACKER]=
  new (std::nothrow) Session_sysvars_tracker();
- m_trackers[TRANSACTION_INFO_TRACKER]=
- new (std::nothrow) Transaction_state_tracker;
 
  for (int i= 0; i < SESSION_TRACKER_END; i++)
  m_trackers[i]->enable(thd);

sql/session_tracker.h

@@ -154,65 +154,6 @@ class Session_state_change_tracker: public State_tracker
 };
 
 
-/**
- Session_tracker
-
- This class holds an object each for all tracker classes and provides
- methods necessary for systematic detection and generation of session
- state change information.
-*/
-
-class Session_tracker
-{
- State_tracker *m_trackers[SESSION_TRACKER_END];
-
- /* The following two functions are private to disable copying. */
- Session_tracker(Session_tracker const &other)
- {
- DBUG_ASSERT(FALSE);
- }
- Session_tracker& operator= (Session_tracker const &rhs)
- {
- DBUG_ASSERT(FALSE);
- return *this;
- }
-
-public:
- Current_schema_tracker current_schema;
- Session_state_change_tracker state_change;
-
- Session_tracker();
- ~Session_tracker() { deinit(); }
-
- /* trick to make happy memory accounting system */
- void deinit()
- {
- delete m_trackers[SESSION_SYSVARS_TRACKER];
- m_trackers[SESSION_SYSVARS_TRACKER]= 0;
- delete m_trackers[TRANSACTION_INFO_TRACKER];
- m_trackers[TRANSACTION_INFO_TRACKER]= 0;
- }
-
- void enable(THD *thd);
-
- /** Returns the pointer to the tracker object for the specified tracker. */
- inline State_tracker *get_tracker(enum_session_tracker tracker) const
- {
- return m_trackers[tracker];
- }
-
- inline void mark_as_changed(THD *thd, enum enum_session_tracker tracker,
- LEX_CSTRING *data)
- {
- if (m_trackers[tracker]->is_enabled())
- m_trackers[tracker]->mark_as_changed(thd, data);
- }
-
-
- void store(THD *thd, String *main_buf);
-};
-
-
 /*
  Transaction_state_tracker
 */
@@ -277,12 +218,17 @@ class Transaction_state_tracker : public State_tracker
  /** Helper function: turn table info into table access flag */
  enum_tx_state calc_trx_state(THD *thd, thr_lock_type l, bool has_trx);
 public:
- /** Constructor */
- Transaction_state_tracker(): tx_changed(TX_CHG_NONE),
- tx_curr_state(TX_EMPTY),
- tx_reported_state(TX_EMPTY),
- tx_read_flags(TX_READ_INHERIT),
- tx_isol_level(TX_ISOL_INHERIT) {}
+
+ bool enable(THD *thd)
+ {
+ m_enabled= false;
+ tx_changed= TX_CHG_NONE;
+ tx_curr_state= TX_EMPTY;
+ tx_reported_state= TX_EMPTY;
+ tx_read_flags= TX_READ_INHERIT;
+ tx_isol_level= TX_ISOL_INHERIT;
+ return State_tracker::enable(thd);
+ }
 
  bool update(THD *thd, set_var *var);
  bool store(THD *thd, String *buf);
@@ -332,12 +278,69 @@ class Transaction_state_tracker : public State_tracker
 
 #define TRANSACT_TRACKER(X) \
  do { if (thd->variables.session_track_transaction_info > TX_TRACK_NONE) \
- {((Transaction_state_tracker *) \
- thd->session_tracker.get_tracker(TRANSACTION_INFO_TRACKER)) \
- ->X; } } while(0)
+ thd->session_tracker.transaction_info.X; } while(0)
 #define SESSION_TRACKER_CHANGED(A,B,C) \
  thd->session_tracker.mark_as_changed(A,B,C)
 
+
+/**
+ Session_tracker
+
+ This class holds an object each for all tracker classes and provides
+ methods necessary for systematic detection and generation of session
+ state change information.
+*/
+
+class Session_tracker
+{
+ State_tracker *m_trackers[SESSION_TRACKER_END];
+
+ /* The following two functions are private to disable copying. */
+ Session_tracker(Session_tracker const &other)
+ {
+ DBUG_ASSERT(FALSE);
+ }
+ Session_tracker& operator= (Session_tracker const &rhs)
+ {
+ DBUG_ASSERT(FALSE);
+ return *this;
+ }
+
+public:
+ Current_schema_tracker current_schema;
+ Session_state_change_tracker state_change;
+ Transaction_state_tracker transaction_info;
+
+ Session_tracker();
+ ~Session_tracker() { deinit(); }
+
+ /* trick to make happy memory accounting system */
+ void deinit()
+ {
+ delete m_trackers[SESSION_SYSVARS_TRACKER];
+ m_trackers[SESSION_SYSVARS_TRACKER]= 0;
+ }
+
+ void enable(THD *thd);
+
+ /** Returns the pointer to the tracker object for the specified tracker. */
+ inline State_tracker *get_tracker(enum_session_tracker tracker) const
+ {
+ return m_trackers[tracker];
+ }
+
+ inline void mark_as_changed(THD *thd, enum enum_session_tracker tracker,
+ LEX_CSTRING *data)
+ {
+ if (m_trackers[tracker]->is_enabled())
+ m_trackers[tracker]->mark_as_changed(thd, data);
+ }
+
+
+ void store(THD *thd, String *main_buf);
+};
+
+
 int session_tracker_init();
 #else
 

sql/sys_vars.cc

@@ -3743,14 +3743,12 @@ bool Sys_var_tx_read_only::session_update(THD *thd, set_var *var)
 #ifndef EMBEDDED_LIBRARY
  if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
  {
- Transaction_state_tracker *tst= (Transaction_state_tracker *)
- thd->session_tracker.get_tracker(TRANSACTION_INFO_TRACKER);
-
  if (var->type == OPT_DEFAULT)
- tst->set_read_flags(thd,
+ thd->session_tracker.transaction_info.set_read_flags(thd,
  thd->tx_read_only ? TX_READ_ONLY : TX_READ_WRITE);
  else
- tst->set_read_flags(thd, TX_READ_INHERIT);
+ thd->session_tracker.transaction_info.set_read_flags(thd,
+ TX_READ_INHERIT);
  }
 #endif //EMBEDDED_LIBRARY
  }
@@ -6145,8 +6143,7 @@ static bool update_session_track_tx_info(sys_var *self, THD *thd,
  enum_var_type type)
 {
  DBUG_ENTER("update_session_track_tx_info");
- DBUG_RETURN(thd->session_tracker.get_tracker(TRANSACTION_INFO_TRACKER)->
- update(thd, NULL));
+ DBUG_RETURN(thd->session_tracker.transaction_info.update(thd, NULL));
 }
 
 static const char *session_track_transaction_info_names[]=

sql/sys_vars.ic

@@ -2219,14 +2219,6 @@ public:
  return TRUE;
  if (var->type == OPT_DEFAULT || !thd->in_active_multi_stmt_transaction())
  {
-#ifndef EMBEDDED_LIBRARY
- Transaction_state_tracker *tst= NULL;
-
- if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
- tst= (Transaction_state_tracker *)
- thd->session_tracker.get_tracker(TRANSACTION_INFO_TRACKER);
-#endif //EMBEDDED_LIBRARY
-
  thd->tx_isolation= (enum_tx_isolation) var->save_result.ulonglong_value;
 
 #ifndef EMBEDDED_LIBRARY
@@ -2250,13 +2242,11 @@ public:
  DBUG_ASSERT(0);
  return TRUE;
  }
- if (tst)
- tst->set_isol_level(thd, l);
- }
- else if (tst)
- {
- tst->set_isol_level(thd, TX_ISOL_INHERIT);
+ if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
+ thd->session_tracker.transaction_info.set_isol_level(thd, l);
  }
+ else if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
+ thd->session_tracker.transaction_info.set_isol_level(thd, TX_ISOL_INHERIT);
 #endif //EMBEDDED_LIBRARY
  }
  return FALSE;

sql/transaction.cc

@@ -32,10 +32,7 @@
 static void trans_track_end_trx(THD *thd)
 {
  if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
- {
- ((Transaction_state_tracker *)
- thd->session_tracker.get_tracker(TRANSACTION_INFO_TRACKER))->end_trx(thd);
- }
+ thd->session_tracker.transaction_info.end_trx(thd);
 }
 #else
 #define trans_track_end_trx(A) do{}while(0)
@@ -51,11 +48,8 @@ void trans_reset_one_shot_chistics(THD *thd)
 #ifndef EMBEDDED_LIBRARY
  if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
  {
- Transaction_state_tracker *tst= (Transaction_state_tracker *)
- thd->session_tracker.get_tracker(TRANSACTION_INFO_TRACKER);
-
- tst->set_read_flags(thd, TX_READ_INHERIT);
- tst->set_isol_level(thd, TX_ISOL_INHERIT);
+ thd->session_tracker.transaction_info.set_read_flags(thd, TX_READ_INHERIT);
+ thd->session_tracker.transaction_info.set_isol_level(thd, TX_ISOL_INHERIT);
  }
 #endif //EMBEDDED_LIBRARY
  thd->tx_isolation= (enum_tx_isolation) thd->variables.tx_isolation;
@@ -162,20 +156,11 @@ static bool xa_trans_force_rollback(THD *thd)
 bool trans_begin(THD *thd, uint flags)
 {
  int res= FALSE;
-#ifndef EMBEDDED_LIBRARY
- Transaction_state_tracker *tst= NULL;
-#endif //EMBEDDED_LIBRARY
  DBUG_ENTER("trans_begin");
 
  if (trans_check(thd))
  DBUG_RETURN(TRUE);
 
-#ifndef EMBEDDED_LIBRARY
- if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
- tst= (Transaction_state_tracker *)
- thd->session_tracker.get_tracker(TRANSACTION_INFO_TRACKER);
-#endif //EMBEDDED_LIBRARY
-
  thd->locked_tables_list.unlock_locked_tables(thd);
 
  DBUG_ASSERT(!thd->locked_tables_mode);
@@ -221,8 +206,8 @@ bool trans_begin(THD *thd, uint flags)
  {
  thd->tx_read_only= true;
 #ifndef EMBEDDED_LIBRARY
- if (tst)
- tst->set_read_flags(thd, TX_READ_ONLY);
+ if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
+ thd->session_tracker.transaction_info.set_read_flags(thd, TX_READ_ONLY);
 #endif //EMBEDDED_LIBRARY
  }
  else if (flags & MYSQL_START_TRANS_OPT_READ_WRITE)
@@ -246,8 +231,8 @@ bool trans_begin(THD *thd, uint flags)
  just from the session's default.
  */
 #ifndef EMBEDDED_LIBRARY
- if (tst)
- tst->set_read_flags(thd, TX_READ_WRITE);
+ if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
+ thd->session_tracker.transaction_info.set_read_flags(thd, TX_READ_WRITE);
 #endif //EMBEDDED_LIBRARY
  }
 
@@ -264,16 +249,16 @@ bool trans_begin(THD *thd, uint flags)
  DBUG_PRINT("info", ("setting SERVER_STATUS_IN_TRANS"));
 
 #ifndef EMBEDDED_LIBRARY
- if (tst)
- tst->add_trx_state(thd, TX_EXPLICIT);
+ if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
+ thd->session_tracker.transaction_info.add_trx_state(thd, TX_EXPLICIT);
 #endif //EMBEDDED_LIBRARY
 
  /* ha_start_consistent_snapshot() relies on OPTION_BEGIN flag set. */
  if (flags & MYSQL_START_TRANS_OPT_WITH_CONS_SNAPSHOT)
  {
 #ifndef EMBEDDED_LIBRARY
- if (tst)
- tst->add_trx_state(thd, TX_WITH_SNAPSHOT);
+ if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)
+ thd->session_tracker.transaction_info.add_trx_state(thd, TX_WITH_SNAPSHOT);
 #endif //EMBEDDED_LIBRARY
  res= ha_start_consistent_snapshot(thd);
  }