[Fwd: Re: [cells-devel] Cells and Threads]

[Duane Searsmith]

Thank you Ken and Attila for your feedback.  I think I have a fair 
understanding of the issues now.  I'm going to do some brainstorming 
over exactly how I would like the threads to interact with the Cells 
engine and then try some experiments with different locking strategies 
and see what happens. 

I'll report back on what I discover.

Best,
-- Duane

Attila Lendvai wrote:
>> > I have an application that is multithreaded and I would like to
>> > explore how to use cells to drive the dataflow.  I've read through the
>> > examples and looked over the code a bit. Seems like I could get in
>> > trouble if multiple threads tried to change a cell with dependencies
>> > at the same time.
>
> i think a global read-write lock could work, which is acquired for
> read whenever a cell is checked for validity and upgraded to writing
> when the cell is invalid and needs recalculation. a write lock locks
> out all other readers and writers, while readers can operate paralel.
>
> interesting questions arise when the calculations themselves have to
> acquire other locks in the application... then it's not trivial to
> ensure the proper locking order everywhere that avoids random
> deadlocks.
>
> but at first i would just create a big-lock-of-the-world which is
> acquired whenever anything is used that uses Cells in your app. but
> this kills paralelism more and more as the Cells-using part of the app
> is bigger and bigger.
>
> hope i said something useful,
>
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