diff options
Diffstat (limited to 'sql/sql_class.cc')
| -rw-r--r-- | sql/sql_class.cc | 75 |
1 files changed, 73 insertions, 2 deletions
diff --git a/sql/sql_class.cc b/sql/sql_class.cc index 2fdf270ae66..d097f7b32a8 100644 --- a/sql/sql_class.cc +++ b/sql/sql_class.cc @@ -57,6 +57,7 @@ #include "transaction.h" #include "debug_sync.h" #include "sql_parse.h" // is_update_query +#include "sql_callback.h" /* The following is used to initialise Table_ident with a internal @@ -1070,6 +1071,7 @@ THD::~THD() DBUG_ENTER("~THD()"); /* Ensure that no one is using THD */ mysql_mutex_lock(&LOCK_thd_data); + mysys_var=0; // Safety (shouldn't be needed) mysql_mutex_unlock(&LOCK_thd_data); add_to_status(&global_status_var, &status_var); @@ -1095,7 +1097,6 @@ THD::~THD() my_free(db); db= NULL; free_root(&transaction.mem_root,MYF(0)); - mysys_var=0; // Safety (shouldn't be needed) mysql_mutex_destroy(&LOCK_thd_data); #ifndef DBUG_OFF dbug_sentry= THD_SENTRY_GONE; @@ -1184,7 +1185,7 @@ void THD::awake(THD::killed_state state_to_set) { thr_alarm_kill(thread_id); if (!slave_thread) - thread_scheduler.post_kill_notification(this); + MYSQL_CALLBACK(thread_scheduler, post_kill_notification, (this)); #ifdef SIGNAL_WITH_VIO_CLOSE if (this != current_thd) { @@ -1253,6 +1254,15 @@ bool THD::store_globals() if (my_pthread_setspecific_ptr(THR_THD, this) || my_pthread_setspecific_ptr(THR_MALLOC, &mem_root)) return 1; + /* + mysys_var is concurrently readable by a killer thread. + It is protected by LOCK_thd_data, it is not needed to lock while the + pointer is changing from NULL not non-NULL. If the kill thread reads + NULL it doesn't refer to anything, but if it is non-NULL we need to + ensure that the thread doesn't proceed to assign another thread to + have the mysys_var reference (which in fact refers to the worker + threads local storage with key THR_KEY_mysys. + */ mysys_var=my_thread_var; /* Let mysqld define the thread id (not mysys) @@ -3182,6 +3192,60 @@ extern "C" bool thd_sqlcom_can_generate_row_events(const MYSQL_THD thd) { return sqlcom_can_generate_row_events(thd); } + +#ifndef EMBEDDED_LIBRARY +extern "C" void thd_pool_wait_begin(MYSQL_THD thd, int wait_type); +extern "C" void thd_pool_wait_end(MYSQL_THD thd); + +/* + Interface for MySQL Server, plugins and storage engines to report + when they are going to sleep/stall. + + SYNOPSIS + thd_wait_begin() + thd Thread object + wait_type Type of wait + 1 -- short wait (e.g. for mutex) + 2 -- medium wait (e.g. for disk io) + 3 -- large wait (e.g. for locked row/table) + NOTES + This is used by the threadpool to have better knowledge of which + threads that currently are actively running on CPUs. When a thread + reports that it's going to sleep/stall, the threadpool scheduler is + free to start another thread in the pool most likely. The expected wait + time is simply an indication of how long the wait is expected to + become, the real wait time could be very different. + + thd_wait_end MUST be called immediately after waking up again. +*/ +extern "C" void thd_wait_begin(MYSQL_THD thd, thd_wait_type wait_type) +{ + MYSQL_CALLBACK(thread_scheduler, thd_wait_begin, (thd, wait_type)); +} + +/** + Interface for MySQL Server, plugins and storage engines to report + when they waking up from a sleep/stall. + + @param thd Thread handle +*/ +extern "C" void thd_wait_end(MYSQL_THD thd) +{ + MYSQL_CALLBACK(thread_scheduler, thd_wait_end, (thd)); +} +#else +extern "C" void thd_wait_begin(MYSQL_THD thd, thd_wait_type wait_type) +{ + /* do NOTHING for the embedded library */ + return; +} + +extern "C" void thd_wait_end(MYSQL_THD thd) +{ + /* do NOTHING for the embedded library */ + return; +} +#endif #endif // INNODB_COMPATIBILITY_HOOKS */ /**************************************************************************** @@ -3365,6 +3429,13 @@ void THD::set_query_id(query_id_t new_query_id) mysql_mutex_unlock(&LOCK_thd_data); } +/** Assign a new value to thd->mysys_var. */ +void THD::set_mysys_var(struct st_my_thread_var *new_mysys_var) +{ + mysql_mutex_lock(&LOCK_thd_data); + mysys_var= new_mysys_var; + mysql_mutex_unlock(&LOCK_thd_data); +} /** Leave explicit LOCK TABLES or prelocked mode and restore value of |