diff options
Diffstat (limited to 'sql/mysqld.cc')
| -rw-r--r-- | sql/mysqld.cc | 50 |
1 files changed, 42 insertions, 8 deletions
diff --git a/sql/mysqld.cc b/sql/mysqld.cc index fd57be234aa..8bafb15eeaa 100644 --- a/sql/mysqld.cc +++ b/sql/mysqld.cc @@ -586,7 +586,8 @@ pthread_mutex_t LOCK_mysql_create_db, LOCK_Acl, LOCK_open, LOCK_thread_count, LOCK_delayed_insert, LOCK_delayed_status, LOCK_delayed_create, LOCK_crypt, LOCK_bytes_sent, LOCK_bytes_received, LOCK_global_system_variables, - LOCK_user_conn, LOCK_slave_list, LOCK_active_mi; + LOCK_user_conn, LOCK_slave_list, LOCK_active_mi, + LOCK_connection_count; /** The below lock protects access to two global server variables: max_prepared_stmt_count and prepared_stmt_count. These variables @@ -722,6 +723,11 @@ char *des_key_file; struct st_VioSSLFd *ssl_acceptor_fd; #endif /* HAVE_OPENSSL */ +/** + Number of currently active user connections. The variable is protected by + LOCK_connection_count. +*/ +uint connection_count= 0; /* Function declarations */ @@ -1343,6 +1349,7 @@ static void clean_up_mutexes() (void) pthread_mutex_destroy(&LOCK_bytes_sent); (void) pthread_mutex_destroy(&LOCK_bytes_received); (void) pthread_mutex_destroy(&LOCK_user_conn); + (void) pthread_mutex_destroy(&LOCK_connection_count); Events::destroy_mutexes(); #ifdef HAVE_OPENSSL (void) pthread_mutex_destroy(&LOCK_des_key_file); @@ -1785,6 +1792,11 @@ void unlink_thd(THD *thd) DBUG_ENTER("unlink_thd"); DBUG_PRINT("enter", ("thd: 0x%lx", (long) thd)); thd->cleanup(); + + pthread_mutex_lock(&LOCK_connection_count); + --connection_count; + pthread_mutex_unlock(&LOCK_connection_count); + (void) pthread_mutex_lock(&LOCK_thread_count); thread_count--; delete thd; @@ -3453,6 +3465,7 @@ static int init_thread_environment() (void) pthread_mutex_init(&LOCK_global_read_lock, MY_MUTEX_INIT_FAST); (void) pthread_mutex_init(&LOCK_prepared_stmt_count, MY_MUTEX_INIT_FAST); (void) pthread_mutex_init(&LOCK_uuid_generator, MY_MUTEX_INIT_FAST); + (void) pthread_mutex_init(&LOCK_connection_count, MY_MUTEX_INIT_FAST); #ifdef HAVE_OPENSSL (void) pthread_mutex_init(&LOCK_des_key_file,MY_MUTEX_INIT_FAST); #ifndef HAVE_YASSL @@ -4704,6 +4717,11 @@ void create_thread_to_handle_connection(THD *thd) thread_count--; thd->killed= THD::KILL_CONNECTION; // Safety (void) pthread_mutex_unlock(&LOCK_thread_count); + + pthread_mutex_lock(&LOCK_connection_count); + --connection_count; + pthread_mutex_unlock(&LOCK_connection_count); + statistic_increment(aborted_connects,&LOCK_status); /* Can't use my_error() since store_globals has not been called. */ my_snprintf(error_message_buff, sizeof(error_message_buff), @@ -4743,15 +4761,34 @@ static void create_new_thread(THD *thd) if (protocol_version > 9) net->return_errno=1; - /* don't allow too many connections */ - if (thread_count - delayed_insert_threads >= max_connections+1 || abort_loop) + /* + Don't allow too many connections. We roughly check here that we allow + only (max_connections + 1) connections. + */ + + pthread_mutex_lock(&LOCK_connection_count); + + if (connection_count >= max_connections + 1 || abort_loop) { + pthread_mutex_unlock(&LOCK_connection_count); + DBUG_PRINT("error",("Too many connections")); close_connection(thd, ER_CON_COUNT_ERROR, 1); delete thd; DBUG_VOID_RETURN; } + + ++connection_count; + + if (connection_count > max_used_connections) + max_used_connections= connection_count; + + pthread_mutex_unlock(&LOCK_connection_count); + + /* Start a new thread to handle connection. */ + pthread_mutex_lock(&LOCK_thread_count); + /* The initialization of thread_id is done in create_embedded_thd() for the embedded library. @@ -4759,13 +4796,10 @@ static void create_new_thread(THD *thd) */ thd->thread_id= thd->variables.pseudo_thread_id= thread_id++; - /* Start a new thread to handle connection */ thread_count++; - if (thread_count - delayed_insert_threads > max_used_connections) - max_used_connections= thread_count - delayed_insert_threads; - thread_scheduler.add_connection(thd); + DBUG_VOID_RETURN; } #endif /* EMBEDDED_LIBRARY */ @@ -8317,7 +8351,7 @@ static void fix_paths(void) (void) my_load_path(mysql_real_data_home,mysql_real_data_home,mysql_home); (void) my_load_path(pidfile_name,pidfile_name,mysql_real_data_home); (void) my_load_path(opt_plugin_dir, opt_plugin_dir_ptr ? opt_plugin_dir_ptr : - get_relative_path(LIBDIR), mysql_home); + get_relative_path(PLUGINDIR), mysql_home); opt_plugin_dir_ptr= opt_plugin_dir; char *sharedir=get_relative_path(SHAREDIR); |