A source code process for MySQL to receive and execute connection commands

A source code process for MySQL to receive and execute connection commands
Call Sequence of functions from top to bottom
Mysqld_main
Handle_connections_methods
Handle_connections_sockets_thread
Handle_connections_sockets
Create_new_thread
Create_thread_to_handle_connection
Handle_one_connection
Do_handle_one_connection
Login_connection
Prepare_new_connection_state
Execute_init_command
Dispatch_command
Execute Command
Switch (command)
{
Case COM_INIT_DB:
...
Case COM_STMT_EXECUTE:
{
Mysqld_stmt_execute (thd, packet, packet_length );
Break;
}
...
}
Execute_loop
Execute
Mysql_execute_command
Switch (lex-> SQL _command) {This is the execution of various query commands. This part of the code is very long.