Re: [PHP4BETA] Databases and multithreading

On Fri, 8 Oct 1999, Andreas Karajannis wrote: > To make the database modules thread safe, I think there are changes > with persistent connection handling required: > > Currently only one identical connection per process is allowed - > attempting to pconnect with the same parameters will return the > previously > established connection out of the plist. If I got things right, we end > up > with several threads using the same single connection. nope - as plist is per-thread as well. > Besides the fact, that this is not what we want (a single db connection) > there will be multiple threads trying to execute quasi simultaneous > queries > on the same connection... see above - that should not be a problem... > > So we need some kind of mutexing for pconnetions: The connection handle > returned from pconnect() mustn't be available for other threads until > explicitly released (via close()) or implicitly released on request > shutdown. s.o. > > Non persistent connections should be ok, since they are kept in a per > thread > resource list. same applies to the persistent ones. > > Any opinions on this from more "threaded" people? this should not really be an issue - question is if the db-libs are thread-save and if they like to be initialized multiple times. if we want connection-pooling we need to think about something different which can share data between threads. regards, tc > > -Andreas > > -- > PHP 4 Beta > > Thies C. Arntzen "One Big-Mac, Small Fries and a Coke!" Digital Collections Phone +49 40 235350 Fax +49 40 23535180 Hammerbrookstr. 93 20097 Hamburg / Germany