> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > Sent: Friday, January 31, 2003 11:38 PM > To: CF-Talk > Subject: CFLOCK/application vars > > > In our application.cfm file we use a statement like > > <cfif not isdefined("application.exchangerate")> > <cflock scope="application" type="exclusive" timeout="60"> > <cf_exchange> > </cflock> > </cfif>.
A few things: 1) Assuming you're using CF 5 or below then you also need to read-lock the IsDefined() statement. IsDefined() is a read of the application scope. 2) You should EXTREMELY limit the amount of code in a lock, especially an exclusive lock. A general rule of thumb is that you shold reduce code in locks to only CFSETs. If the operation in this lock takes a long time (and you're locking properly) then this will create a MARKED impact on performance under load. The code you present indicates a little bit of a misunderstanding about locking. It's heart is in the right place, so to speak, but it's not really doing the job. I invite you to read my in-depth guide to locking in ColdFusion for more information: http://www.depressedpress.com/DepressedPress/Content/ColdFusion/Guides/L ocking/Index.cfm The guide is most applicable to CF 5 and below, but the concepts are sound in CFMX. The main difference is that CFMX doesn't suffer the stability problems a lack of locking in CF 5- had. So, for example, in CFMX you don't have to lock that IsDefined(). Jim Davis ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Archives: http://www.houseoffusion.com/cf_lists/index.cfm?forumid=4 Subscription: http://www.houseoffusion.com/cf_lists/index.cfm?method=subscribe&forumid=4 FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Your ad could be here. Monies from ads go to support these lists and provide more resources for the community. http://www.fusionauthority.com/ads.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
