[racket-dev] feature request: thread-safe memoize-evt

On Thu, 2015-01-29 at 16:41 -0600, Robby Findler wrote:
> That is, I thought you could just create a separate thread that sync's
> on E_b and then whenever you get a value from it, then the E_m would
> just continue to produce that all the time. But I think you're saying
> that wouldn't work?

The problem is that the auxiliary thread would always wait for the E_b,
even when nobody is interested in the result anymore. Moreover, putting
the wait in another thread would require the E_b to be thread safe.