Using fprintf or DBUG_PRINT to print messages in mysqld

[Salil Bhagurkar]

Hello All,

I am trying to understand the code flow of mysql-5.5.15 mysqld server.

1. I am able to use fprintf(stdout, ..) to print out messages to the console 
in the main startup code of mysqld.

2. I cannot use fprintf in any of the thread context to print messages to 
the console. Why is this?

3. If I compile the source code with the debug option and use DBUG_PRINT, 
then it does not work in some cases, specifically in the function 
do_handle_one_connection() in sql/sql_connect.cc.

4. DBUG_PRINT works and is used in the function do_command which is called 
by the do_handle_one_connection() method. From what I observed, is 
DBUG_ENTER always required to be able to DBUG_PRINT?

Thanks,
Salil Bhagurkar