Shared variables such as application and session should be locked, however the lock really only needs to be there on a write. Writing to a shared variable can cause the system to hang or enter a state of confusion, hence the locking of the variable.
However although recommended to lock all reads and writes, I personally have never done it on a read of said such variables. It is also very safe to do the following... <cflock> <cfset application.test = "Test"> <cfoutput>Hello</cfoutput> </cflock> All it means is that while this bit of code is being run, nobody else can access this bit of code until this process has released the lock. If 2 applications write to a variable at the exact same time (rare, but very possible) CF can enter a state of deadlock and will require the server to be restarted. For more information on this, consult the manual about the attributes scope and type that allow the variable to be read only or exclusive and to define the type of variable it is. For example is it an application, server or even session scope. But the point is well within what has been discussed many times on this list, should we or should we lock reading of variables. Like I said I don't when reading them, and have never had any problems (touch wood) with this method. But there are many reasons why one should use application scope variables, for example to determine how many people are actually logged into a membership system as a good example. -----Original Message----- From: Shawn Regan [mailto:[EMAIL PROTECTED]] Sent: Thursday, 27 June 2002 12:18 AM To: CF-Talk Subject: RE: What is the best variable scope? Why do you need to lock it? Shawn Regan ______________________________________________________________________ Structure your ColdFusion code with Fusebox. Get the official book at http://www.fusionauthority.com/bkinfo.cfm FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Archives: http://www.mail-archive.com/[email protected]/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
