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Asynchronous evaluation: Is it possible?


Currently we have a limited number of ways to perform asynchronous evaluation.


The most common is through Dynamic and Manipulate.


Using Dynamic, we can have part of a cell update independent of whatever we're working on:


Dynamic["x = " <> ToString@x]
For[i = 0, i < 100, i++, Pause[0.05]; x = i^2];


Similarly, we can use Manipulate to continuously evaluate an expression and output the result:


Manipulate[
 {r, v} = {r + dt v, v - dt r};
 Show[Graphics@Point[r], PlotRange -> {{-2, +2}, {-2, +2}}],
 {{dt, 0.01}, 0.01, 1},

 Initialization -> {
   r = {0, 1};
   v = {1, 0};
   }]


We also have a way to submit jobs and have them work independently of each, however it does block any further input:


jobs = Table[
   ParallelSubmit[
    SingularValueList[RandomReal[1, {1000, 1000}]]],
   {10}];

WaitAll[jobs]

The third option gets the closest to being an asynchronous evaluation, however it fails in that it requires any further input to be blocked. What I would love to see is some function, tentatively named AsynchronousEvaluate, which does exactly what it name says:



AsynchronousEvaluate[Pause[10];]
Print["Hello!"]; (* Printed immediately *)

Is there any way we can get close to achieving this?


My dream is to be able to queue up a job for processing on a parallel kernel with certain constraints (Like MemoryConstrained) and be able to just "set and forget." When processing is finished, the result will be returned to me. But in the mean time I can still be productive by doing something else.


Asynchronous evaluation is the only piece that's missing from this, and I'd like to do it if it's possible.




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