No offense, but that is nonsense.
My Cold Fusion server is still multi-threaded and multi-processed. It is still
handling every incoming request at the same time.
The only time it will act "single threaded" is when two requests attempt to read an
Application scope variable at the same time. And guess what? That is exactly the same
thing that will happen if you DONT use automatic read locking, but properly use
<CFLOCK> around your Application variables.
Automatic read locking doesn't lock the entire page request, (which would be single
threading the entire server). It locks read access around those variables that need it.
This is not just an academic issue for me. I have a site running with 10-100 reads
from an Application structure on every page. To make the code more readable, I am
using automatic read locking for Application scope variables instead of
<CFLOCK>#Application.myvar#</CFLOCK> tens or hundreds of times on each page.
On a related note, if I have automatic read locking enabled for Application scope and
I assign a local Variable to an Application variable, it will essentially make a copy
to the pointer. Is CF smart enough then to automatically lock accesses to this local
Variables, which is pointing into Application space?
< !--- automatic read locking is ON for Application variables --->
< cfset myvar = Application.bigvar>
< cfoutput> #myvar# </cfoutput> < !--- <<<=== IS THIS AUTOMATICALLY LOCKED?? --->
At 02:13 PM 12/19/00 -0700, Richard Kern wrote:
>It was expressed before that turning this on via the server will essentially
>drop your application to single thread mode, slowing down all responses from
>the system. Remember that CF is server side so doing this is like knocking
>on the door and opening it for each request and then closing it before
>anyone else enters, no matter how many people are queued at the door.
>
>Richard Kern
>
>-----Original Message-----
>From: Peter Theobald [mailto:[EMAIL PROTECTED]]
>Sent: Tuesday, December 19, 2000 1:16 PM
>To: CF-Talk
>Subject: LOCKING revisited...
>
>
>Ok, given that we all agree:
>
>** Access to shared variables should *ALWAYS* be locked **
>
>Then why on Earth shouldn't I just turn on Automatic Read Locking for
>Application (and Session et al if I use them) scope and only worry about
>write locking in my code?
>
>Why doesn't everyone do that, with the rare exception of some code that has
>unusual locking needs.
>
>I've heard the argument that automatic read locking is a slight performance
>hit. It couldn't be more of a hit than parsing <cflock> </cflock> around
>every access and still doing the read lock anyway!
>
>
>
>---------------------------------------------------------------------------
>Peter Theobald, Chief Technology Officer
>LiquidStreaming http://www.liquidstreaming.com
>[EMAIL PROTECTED]
>Phone 1.212.545.1232 x204 Fax 1.212.545.0938
>
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