Pavlos Christoforou wrote:
I am thinking of implementing some kind of event loop in my bobo app (maybe in Zope too) but ... I don't know much about threads or signals.
Do win NT/95 support some simple signals like alarm?
I understand that having the eventloop running in a different thread can be disastrous, since a function registered in the eventloop might fight for the same resources as a function running in the main loop.
This does have to be handled carefully. It will become much easier in Zope 2 (with the thing formerly known as BoboPOS3), but it is reasonably straightforward now. The way we've done this in the past is to define an application lock and set the acquire and release methods of the lock to __bobo_before__ and __bobo_after__ in the published module (Main in the Zope Framework), so that they get called by Bobo^H^H^H^HZPublisher when it handles a request. Then, when the scheduler needs to access application objects, it acquires the application lock with __bobo_before__ and releases it with __bobo_after__, just like ZPublisher does. You can see remnants of this in the (mostly defunct) scheduler package. As I mentioned above, the thing FKA BoboPOS3 will make this much easier. In fact, it will eliminate the need for an application lock! Jim -- Jim Fulton mailto:jim@digicool.com Technical Director (888) 344-4332 Python Powered! Digital Creations http://www.digicool.com http://www.python.org Under US Code Title 47, Sec.227(b)(1)(C), Sec.227(a)(2)(B) This email address may not be added to any commercial mail list with out my permission. Violation of my privacy with advertising or SPAM will result in a suit for a MINIMUM of $500 damages/incident, $1500 for repeats.