FreeTDS Development Group

[Peter Deacon <peterd AT iea-software.com>]

On Thu, 14 Jul 2005, Frediano Ziglio wrote:

> I know however it's a nice feature to have and easy to implement.
> In early days there where an executable linked to some few libraries
> (like libc) but nowadays in context like

>               <- PHP <- php_mssql.so    <-
> httpd (Apache) <- Python <- ???.so       <- libdblib.so
>               <- mod_perl <- DBD::DBLib <-

> is difficult to define who should call dbexit... you end up in
> situations where the better way is to call only dbinit... I got the same
> problem with socket and windows. Under windows you have to initialize
> socket library with WSAStartup, use sockets and then you should call
> WSACleanup. However after WSACleanup you cannot call any socket API. In
> 3 cases (OCX used in an ASP page, ISAPI and an extended store procedure
> in mssql) I decided to NOT call WSACleanup to prevent main program
> (respectively IIS, IIS and mssql) to stop working correctly (in IIS case
> I decided to not call WSAStartup too...). Now in FreeTDS you can call
> safety dbinit/dbexit, just call dbinit and dbexit once.

FWIW WSAStartup/Cleanup and most routines that I know of that behave in 
the same way use internal reference counts to prevent problems like the 
above from occuring.  You just need to make sure that you call init the 
same number of times you can cleanup.  Only the last call to cleanup 
actually does anything.

Have Fun!
Peter