How to end time-out querying

[guyson]

Dear all,
       here is my question:
Q1--- in this function (mysql_options() ),the desc of MYSQL_OPT_READ_TIMEOUT in the
Reference Manual 5.0 is as follows:"The timeout in seconds for attempts to read from the
server...".My question is how should I understand this word "read",does it means access
the result-set or excute sql or something others?I mean,what on earth does it read?
 
Q2---About this function mysql_query().If the querying time is too long,how can I stop it
to let the programm return normally,Is there any options can set or should i just
Interrupt the work thread?If i choosed to terminate the thread ,which way is correct?Can
you tell me ?
 
-----------Thank you for bearing my broken English.Waiting for your reply.