MySQL连接查询流程源码

http://blog.itpub.net/29510932/viewspace-2129300/

初始化:

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1. main
2. |-mysqld
3. |-my_init // 初始话线程变量，互斥量
4. |-load_defaults // 获取配置
5. |-init_common_variables // 初始化变量
6. |-init_server_components // 初始化插件
7. | |-plugin_init
8. | | |-plugin_initialize
9. | |-initialize_storage_engine
10. |-network_init // 监听网络
11. |-grant_init
12. |-servers_init
13. |-udf_init

插件启动:

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1. main
2. |-mysqld_main
3. |-init_server_components
4. |-plugin_init
5. |-plugin_initialize
6. |-ha_initialize_handlerton
7. |-innobase_init

登录过程:

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1. main
2. |-mysqld_main
3. |-network_init // 建立socket监听，一个针对网络，一个针对unix域
4. |-handle_connections_sockets
5. |-poll
6. |-mysql_socket_accept // 和客户端建立连接
7. |-create_new_thread // 针对每个socket连接建立一个新的线程
8. |-create_thread_to_handle_connection
9. |-waiting_thd_list->push_back(thd);mysql_cond_signal(&COND_thread_cache); // 已有连接处理线程时，通过信号唤醒，处理线程函数为pfs_spawn_thread
10. |-mysql_thread_create(启动的线程执行函数，inline_mysql_thread_create)
11. |-spawn_thread_v1
12. |-pthread_create(pfs_spawn_thread)

处理连接:

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1. pfs_spawn_thread
2. |-handle_one_connection
3. |-do_handle_one_connection
4. |-MYSQL_CALLBACK_ELSE(thread_scheduler, init_new_connection_thread, (), 0)
5. | |-init_new_connection_handler_thread
6. |-thd_prepare_connection
7. | |-login_connection // 判断是否可以login，不可以则断开连接返回错误
8. | | |-check_connection
9. | | | |-acl_authenticate
10. | | | |-do_auth_once
11. | | | |-native_password_authenticate
12. | | | |-server_mpvio_write_packet
13. | | | | |-send_server_handshake_packet // 发送handshake包到客户端
14. | | | | |-my_net_write
15. | | | | | |-net_write_buff // 将数据写入到内存
16. | | | | |-net_flush // 将内存中数据发送到网络
17. | | | |-server_mpvio_read_packet // 从客户端接收Login Request信息
18. | | | |-my_net_read
19. | | |-Protocol::end_statement
20. | | |-Protocol::send_ok
21. | | |-net_send_ok // 发送response ok
22. | | |-my_net_write
23. | |-prepare_new_connection_state
24. |-do_command
25. |-dispatch_command
26. |-mysql_parse

select命令:

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1. pfs_swpawn_thread
2. |-handle_one_connection
3. |-do_handle_one_connection
4. |-do_command
5. |-dispatch_command
6. |-mysql_parse
7. |-parse_sql
8. | |-MYSQLparse
9. |-mysql_execute_command
10. |-select_precheck
11. | |-check_table_access
12. |-execute_sqlcom_select
13. | |-open_normal_and_derived_tables
14. | |-open_tables
15. | | |-open_and_process_table
16. | | |-open_table(THD *thd, TABLE_LIST *table_list, Open_table_context *ot_ctx)
17. | | |-Table_cache::get_table
18. | | |-get_table_share_with_discover
19. | | | |-get_table_share
20. | | | |-open_table_def
21. | | |-my_malloc // 申请表数据结构
22. | | |-open_table_from_share
23. | | |-handler::ha_open
24. | | |-ha_innobase::open
25. | | |-dict_table_open_on_name
26. | | |-dict_load_table
27. | | |-btr_pcur_is_on_user_rec
28. | | |-dict_load_table_low
29. | | | |-dict_mem_table_create
30. | | |-fil_space_for_table_exists_in_mem
31. | | |-fil_open_single_table_tablespace // 打开表空间文件
32. | |-mysql_handle_derived
33. |-handle_select
34. |-mysql_select
35. |-mysql_prepare_select
36. | |-JOIN::prepare
37. |-mysql_execute_select
38. |-JOIN::exec
39. |-select_send::send_result_set_metadata
40. | |-Protocol::send_result_set_metadata
41. |-do_select
42. |-sub_select
43. |-evaluate_join_record
44. |-end_send
45. |-select_send::send_data
46. |-Protocol::write