MySQL connection query process source code Analysis

Initialization

main    |-mysqld        |-my_init   // 初始话线程变量，互斥量        |-load_defaults // 获取配置        |-init_common_variables // 初始化变量        |-init_server_components    // 初始化插件        |   |-plugin_init        |   |   |-plugin_initialize        |   |-initialize_storage_engine        |-network_init  // 监听网络        |-grant_init        |-servers_init        |-udf_init

Plug-in Startup

main    |-mysqld_main        |-init_server_components            |-plugin_init                |-plugin_initialize                    |-ha_initialize_handlerton                        |-innobase_init

Logon process

Main|-mysqld_main        |-network_init//Establish socket listener, one for network, one for UNIX domain        |-handle_connections_sockets            |-poll            |-mysql_socket_accept//And Client connection established            |-create_new_thread//Create a new thread for each socket connection                |-create_thread_to_handle_connection                    |-waiting_thd_list->push_back (THD); mysql_cond_signal (&cond_thread_cache); The processing thread function is pfs_spawn_thread when there is a connection processing thread that wakes through the signal                    |-mysql_thread_create (startup thread execution function, inline_mysql_thread_create)                        |-SPAWN_THREAD_V1                            |-pthread_create (Pfs_spawn_thread)

Processing connections

Pfs_spawn_thread|-handle_one_connection        |-do_handle_one_connection            |-mysql_callback_else (Thread_scheduler, Init_new_connection_thread, (), 0)            | |-init_new_connection_handler_thread            |-thd_prepare_connection            | |-login_connection//To determine if login is possible, no disconnect return error            |   | |-check_connection            |   |   | |-acl_authenticate            |   |       | |-do_auth_once            |   |           | |-native_password_authenticate            |   |               | |-server_mpvio_write_packet            |   |               |   | |-send_server_handshake_packet//Send handshake package to client            |   |               |       | |-my_net_write            |   |               |       |   | |-net_write_buff//Writes data to memory            |   |               |       | |-net_flush//sending in-memory data to the network            |   |               | |-server_mpvio_read_packet//Receive login request information from client            |   |                   | |-my_net_read            |   | |-protocol::end_statement            |       | |-PROTOCOL::SEND_OK            |           | |-NET_SEND_OK//Send response OK            |               | |-my_net_write            | |-prepare_new_connection_state            |-do_command                |-dispatch_command                    |-mysql_parse

Processing Command Select

Pfs_swpawn_thread|-handle_one_connection        |-do_handle_one_connection            |-do_command                |-dispatch_command                    |-mysql_parse                        |-parse_sql                        | |-mysqlparse                        |-mysql_execute_command                            |-select_precheck                            | |-check_table_access                            |-execute_sqlcom_select                            | |-open_normal_and_derived_tables                            | |-open_tables                            |   | |-open_and_process_table                            |       | |-open_table (THD *thd, table_list *table_list, Open_table_context *ot_ctx)                            |           | |-table_cache::get_table                            |           | |-get_table_share_with_discover                            |           |   | |-get_table_share                            |           |       | |-open_table_def                            |           | |-my_malloc//Application form data structure                            |           | |-open_table_from_share                            |               | |-handler::ha_open                            |                   | |-ha_innobase::open                            |                       | |-dict_table_open_on_name                            |                           | |-dict_load_table                            |                               | |-btr_pcur_is_on_user_rec                            |                               | |-dict_load_table_low                            |                               |   | |-dict_mem_table_create                            |                               | |-fil_space_for_table_exists_in_mem                            |                               | |-fil_open_single_table_tablespace//opening tablespace files                            | |-mysql_handle_derived                            |-handle_select                                |-mysql_select                                    |-mysql_prepare_select                                    | |-join::p repare                                    |-mysql_execute_select                                        |-join::exec                                            |-select_send::send_result_set_metadata                                            | |-protocol::send_result_set_metadata                                            |-do_select                                                |-sub_select                                                    |-evaluate_join_record                                                        |-end_send                                                            |-select_send::send_data                                                                |-protocol::write

MySQL connection query process source code Analysis