diff options
| author | unknown <monty@mysql.com> | 2004-08-24 18:00:45 +0300 |
|---|---|---|
| committer | unknown <monty@mysql.com> | 2004-08-24 18:00:45 +0300 |
| commit | 20f24a422bd8ff8747c2e75c03b9f207875ad880 (patch) | |
| tree | 0889ac56857787d5328320949bb6d8339acf6407 /sql/sql_class.cc | |
| parent | 4e7cb1ce4892a025de932fe969676a1131e004b4 (diff) | |
| download | mariadb-git-20f24a422bd8ff8747c2e75c03b9f207875ad880.tar.gz | |
Portablity fixes & simple optimizations
sql/ha_ndbcluster.cc:
Added missing cast
sql/item.cc:
Portability fix (for windows)
sql/lock.cc:
Cleanup + more comments
sql/sql_class.cc:
Portability fix + more comments
sql/sql_select.cc:
Portability fix
sql/sql_table.cc:
Simpler handling of auto_increment in ALTER TABLE
Diffstat (limited to 'sql/sql_class.cc')
| -rw-r--r-- | sql/sql_class.cc | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/sql/sql_class.cc b/sql/sql_class.cc index 23fef44c964..e49cfecba9d 100644 --- a/sql/sql_class.cc +++ b/sql/sql_class.cc @@ -155,11 +155,13 @@ bool foreign_key_prefix(Key *a, Key *b) ** Thread specific functions ****************************************************************************/ -THD::THD():user_time(0), current_arena(this), is_fatal_error(0), - last_insert_id_used(0), - insert_id_used(0), rand_used(0), time_zone_used(0), - in_lock_tables(0), global_read_lock(0), bootstrap(0) +THD::THD() + :user_time(0), global_read_lock(0), is_fatal_error(0), + last_insert_id_used(0), + insert_id_used(0), rand_used(0), time_zone_used(0), + in_lock_tables(0), bootstrap(0) { + current_arena= this; host= user= priv_user= db= ip=0; host_or_ip= "connecting host"; locked=some_tables_deleted=no_errors=password= 0; @@ -439,10 +441,13 @@ void THD::awake(bool prepare_to_die) it is the true value but maybe current_mutex is not yet non-zero (we're in the middle of enter_cond() and there is a "memory order inversion"). So we test the mutex too to not lock 0. + Note that there is a small chance we fail to kill. If victim has locked - current_mutex, and hasn't entered enter_cond(), then we don't know it's - going to wait on cond. Then victim goes into its cond "forever" (until - we issue a second KILL). True we have set its thd->killed but it may not + current_mutex, but hasn't yet entered enter_cond() (which means that + current_cond and current_mutex are 0), then the victim will not get + a signal and it may wait "forever" on the cond (until + we issue a second KILL or the status it's waiting for happens). + It's true that we have set its thd->killed but it may not see it immediately and so may have time to reach the cond_wait(). */ if (mysys_var->current_cond && mysys_var->current_mutex) |