[Webware-discuss] dealing with expensive resources and thread-safety

[Max I. <ma...@uc...>]

Hi,

I have a question regarding usage of db connection in WebKit and 
(related to it), how thread-safe servlets are.

Currently I have a db conn. as a module global variable in a sitepage 
and it is used by several servlets. But I'm not sure this is a good way 
to deal with db. Anyway it is probably buggy as most DB-API interfaces 
are not thread-safe and WebKit is multithreaded and hence there is a 
possiblilty for crash due to simulationous access to the same conn from 
multiple threads.

I think db conn should be created when needed and released when 
unneeded, as to conserve system resources. But was is the best way to 
achieve this in WebKit?

I think about using a conn pool and storing a conn in a session variable 
or in a servlet instance variable (via awake/sleep). Only not sure 
whether it would be guaranteed that it can't be accessed from mulitiple 
threads.

If session variable or servlet instance variable can be accessed from 
mulitiple threads then I see no other route as to request conn only 
where it needed (in a method body) and release it immediately.

What do you think?