[whatwg] [Web workers] An attribute describing the "best" number of worker to invoke in a delegation use case

[Boris Zbarsky]

On 11/11/09 10:19 PM, David Bruant wrote:
> This attribute have the following properties :
> - It's only dependant on the hardware, the operating system and the
> WebWorker implementation (thus, it is not dynamically computed by the
> user agent at each call and two calls in the same
> hardware//OS//WebWorker implementation have the same result).
> - In the same running conditions (same memory available, same number of
> process running concurrently...) running the "same algorithm" (an easy
> delegation algorithm) has a significantly better performance with
> (navigator.optimalWorkerNumber) workers than
> (navigator.optimalWorkerNumber - 1) workers
> - In the same running conditions, running the same algorithm has no
> significantly better performance with (navigator.optimalWorkerNumber +1)
> workers than (navigator.optimalWorkerNumber) workers

I believe that these conditions are mutually contradictory.

Indeed, condition 1 requires that optimalWorkerNumber be a constant 
independent of what the browser itself and other applications are doing.

Condition 2 requires that running with navigator.optimalWorkerNumber has 
better performance than running with (navigator.optimalWorkerNumber - 1) 
workers.  In particular, it requires that this be the case even if there 
is already one worker doing something (due to condition 1).  This 
implies that performance with (navigator.optimalWorkerNumber+1) workers 
be better than that with navigator.optimalWorkerNumber workers, which 
directly violates condition 3.

-Boris