MySQL5.7.28代码初始化流程

==MySQL5.7.28代码初始化流程==
int mysqld_main(int argc, char **argv)
static int init_server_components() //plugin_register_builtin_and_init_core_se 初始化innodb引擎。
mysqld_socket_acceptor->connection_event_loop();
void connection_event_loop()
Connection_handler_manager::process_new_connection(Channel_info* channel_info)
bool Per_thread_connection_handler::add_connection(Channel_info* channel_info)
extern "C" void *handle_connection(void *arg)
bool thd_prepare_connection(THD *thd)
static void prepare_new_connection_state(THD* thd)
void THD::init_for_queries(Relay_log_info *rli);

handle_connection在循环中：
bool do_command(THD *thd)  //在此循环读取客户端请求。SQL解释-SQL优化-SQL执行。
bool dispatch_command(THD *thd, const COM_DATA *com_data, enum enum_server_command command)
void mysql_parse(THD *thd, Parser_state *parser_state) //sql_parse.cc SQL语法解释。
int mysql_execute_command(THD *thd, bool first_level = false);
bool handle_query(THD *thd, LEX *lex, Query_result *result, ulonglong added_options, ulonglong removed_options); //执行查询。

/home/dttchat/mysqldms5.7.28/bin/mysqld --initialize --user=dttchat --basedir=/home/dttchat/mysqldms5.7.28 --datadir=/home/dttchat/mysqldms5.7.28/data
/home/dttchat/mysqldms5.7.28/bin/mysqld_safe --user=dttchat --basedir=/home/dttchat/mysqldms5.7.28 --datadir=/home/dttchat/mysqldms5.7.28/data&
/home/dttchat/mysqldms5.7.28/bin/mysql -u root -h 127.0.0.1 -p'dttchat'
/home/dttchat/mysqldms5.7.28/bin/mysqladmin -u root shutdown -p'dttchat'
/home/dttchat/mysqldms5.7.28/bin/mysqld_safe --defaults-file=/home/dttchat/mysqldms5.7.28/data/auto.cnf&
gdb --args /home/dttchat/mysqldms5.7.28/bin/mysqld --defaults-file=/home/dttchat/mysqldms5.7.28/data/auto.cnf

CREATE USER 'root'@'*' IDENTIFIED BY 'dttchat';
GRANT ALL ON *.* TO 'root'@'*';
CREATE USER 'root' IDENTIFIED BY 'dttchat';
GRANT ALL ON *.* TO 'root';
ALTER USER 'root'@'localhost' IDENTIFIED BY 'dttchat';