coldfusion threads within loops losing scope

Question

I'm currently struggling to get to grips with threads. I have a feeling it might be to do with my scopes; however, I can't see where I am going wrong with this.

My CFC contains the function below:

<cfcomponent output="false" hint="thread stuff.">
    <cffunction name="threadTest" access="public" returntype="struct">
    <cfscript>
        local.lstOne            = "1,2,3,4,5,6";
        local.a                 = [];
        local.s                 = {};
        local.lst               = "";

        for(local.x = 1; local.x lte listlen(local.lstOne,','); local.x++){
            local.lst           &= (len(local.lst) gt 0) ? ',thr#local.x#' : 'thr#local.x#';

            thread action="run" name="thr#local.x#" nIndex="#local.x#" aArray="#local.a#"{

                thread.y        = attributes.nIndex;
                thread.aArray   = attributes.aArray;
                if(thread.y mod 2){
                    thread.c    = 1;
                } else {
                    thread.c    = 0;
                }

                thread.stArgs       = {};
                thread.stArgs.nMod  = thread.c;

                arrayAppend(thread.aArray, thread.stArgs);
            }
        }

        threadJoin(local.lst);

        local.s.counts          = local.a;

        return local.s;
    </cfscript>
</cffunction>
</cfcomponent>

and I have a CFM page that looks a little like this:

<cfscript>
theThread = createObject( "component", "ThreadStuff" ).init();
theThread.threadTest();
</cfscript>

When I run this, coldfusion comes back with the error Element X is undefined in LOCAL..

I can't work out why it is losing local.x after the first iteration of the loop (I have proven this by doing a dump at the beginning of the loop and at the end of the loop, and it can't get to local.x = 2).

where might I be going wrong?

Answer 1

Coldfusion 9.0.0 (version used in this question: 9,0,0,251028) has a bug where the local scope breaks when a thread is used within a loop within a function.

This issue is fixed in Coldfusion 9.0.1, see details here: http://helpx.adobe.com/coldfusion/kb/issues-fixed-coldfusion-9-0.html id:80153.

Answer 2

If the problem is that variable local.x is not incrementing, start by commenting out all the threading stuff. Replace it with a writedump of local. Writedump the local scope before and after the loop as well.

Once you get local.x incrementing, add empty threads. Continue to writedump the local scope so you can see if this is what causes the problem. If local.x is still incrementing, add very small bits of code until you find the bit that causes the problem.