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mirror of https://github.com/MariaDB/server.git synced 2025-11-28 17:36:30 +03:00

Speed up connection time:

-Change my_rnd() slightly to make it safer if two threads use it at the same time.
-Avoid some sprintf and strmov in vio.
-Changed thread_count to be automically incremented (instead of under LOCK_thread_count).
-Thread cache now uses LOCK_thread_cache instead of LOCK_thread_count.
-Moved delete thd out from LOCK_thread_count.
-Save some mysql_cond_broadcast(&COND_thread_count) calls.
-Removed call to getsockname() during connect.
-Initialize random generator without locks.

Other things:
-Added thread_safe_decrement32() and thread_safe_increment32()
-Removed sql_rnd_with_mutex() and get_thread_running()

Thanks to Yoshinori Matsunobu for the benchmark of connection speed and to
Domas Mituzas for the inspiration for many of the fixes.
 

include/violite.h:
  Change desc to a string pointer
mysql-test/suite/perfschema/r/all_instances.result:
  Added new mutex
mysys/my_rnd.c:
  Change my_rnd() slightly to make it safer if two threads use it at the same time.
sql/event_scheduler.cc:
  Changed thread_count to be automically incremented
  Moved some safe things out from LOCK_thread_count.
  Simplify deleting of THD for running thread.
sql/mysqld.cc:
  Changed thread_count to be automically incremented
  Thread cache now uses LOCK_thread_cache instead of LOCK_thread_count
  Added delete_running_thd()
  Moved delete thd out from LOCK_thread_count
  More DBUG_ENTER
  Only call  mysql_cond_broadcast(&COND_thread_count) if thread_count is 0
  Removed call to getsockname() (old not anymore needed check)
sql/mysqld.h:
  Removed sql_rnd_with_mutex() (not needed anymore)
  Removed not used function get_thread_running()
  Added thread_safe_decrement32() and thread_safe_increment32()
  Simplified dec_thread_running() and inc_thread_running()
sql/sql_class.cc:
  Removed thd_lock_thread_count() and thd_unlock_thread_count()
  Initialize random generator without locks
sql/sql_insert.cc:
  Changed thread_count to be automically incremented
sql/sql_parse.cc:
  Changed thread_count to be automically incremented
vio/vio.c:
  Don't generate 'desc' with sprintf/strmov. Assign a pointer instead.
  (Good enough as this is just for debugging)
This commit is contained in:
Michael Widenius
2013-03-20 01:46:35 +02:00
parent 8b047ac5c4
commit 615d51b650
10 changed files with 178 additions and 176 deletions

View File

@@ -349,29 +349,6 @@ void thd_set_thread_stack(THD *thd, char *stack_start)
thd->thread_stack= stack_start;
}
/**
Lock connection data for the set of connections this connection
belongs to
@param thd THD object
*/
void thd_lock_thread_count(THD *)
{
mysql_mutex_lock(&LOCK_thread_count);
}
/**
Lock connection data for the set of connections this connection
belongs to
@param thd THD object
*/
void thd_unlock_thread_count(THD *)
{
mysql_cond_broadcast(&COND_thread_count);
mysql_mutex_unlock(&LOCK_thread_count);
}
/**
Close the socket used by this connection
@@ -947,7 +924,14 @@ THD::THD()
protocol_binary.init(this);
tablespace_op=FALSE;
tmp= sql_rnd_with_mutex();
/*
Initialize the random generator. We call my_rnd() without a lock as
it's not really critical if two threads modifies the structure at the
same time. We ensure that we have an unique number foreach thread
by adding the address of the stack.
*/
tmp= (ulong) (my_rnd(&sql_rand) * 0xffffffff);
my_rnd_init(&rand, tmp + (ulong) &rand, tmp + (ulong) ::global_query_id);
substitute_null_with_insert_id = FALSE;
thr_lock_info_init(&lock_info); /* safety: will be reset after start */