how create multithreading dynamically?

[威海的风]

Hi, 

There is a 2D-Array.I need create multithreading for processing it row by row.Is there any way  can do that?If can,please give me a example vi.Thanks a lot!

[RavensFan]

What version of LabVIEW do you have?  LabVIEW 2009 has a new feature on For Loops that allow you to have the iterations run in parallel.

What processing do you want to do on each row?  You could use several index array functions to get a particular row, and pass the data off into queues and have parallel while loops operating on the elements that come out of the queues.

[威海的风]

hi,Ravens Fan

My labview version is 8.5.My Application controls equipments.The data  should process one by one in the same row, but the data can process at the same time in different rows.    

[RavensFan]

How many do you want to run at the same time?  Let's say 4.  Use decimate array to break your array into 4 parts.  Feed each part to its own For Loop for processing.  Use Interleave Array to put the results of the 4 loops back together.

[威海的风]

...Row's number is uncertain,so I should create multithreading dynamically.

[RavensFan]

It will handle any number of rows.

I don't see any way you can handle an unspecified number of threads.  At some point you are going to have to determine how many different rows you want to be processing at the same time.  There is a practical limit, and that limit isn't that high of a number.  Once you determine how many to process at the same time, then you just decimate your array of whatever size it is among those X number of processes.

[威海的风]

Hi,Ravens Fan

I create a reentrant vi for processing which is invoked dynamiclly by main vi  in the example.Is it multithreading ?

[Baji]

I dont think its mutlithreading (as per the data flow model).

[威海的风]

Hi,Baji

I think the main vi just invokes the process vi and  doesnt wait until it done.Only the time running is different each other. 

[Baji]

In the for loop the process VI waits for the input and it gets executed.So nothing is happening in parallel.Check the attachment