Moneta pool busy-loops with ttl option

[simmons]

I'm using Moneta 1.4.1, and noticed that when using Moneta::Pool with the ttl option, the pool management thread will start busy-looping after the ttl interval, thus using 100% of a CPU core. I'm using Moneta with the Redis adapter, and I've seen this behavior in Ruby version 2.7.0p0, 2.7.2p137, and 3.0.0p0.

With the moneta and redis gems installed, and a Redis server running, I can reproduce this with the following script:

#!/usr/bin/env ruby
require 'moneta'
cache = Moneta.build do
  use(:Pool, min: 2, max: 4, ttl: 5, timeout: 2) do
    adapter :Redis, url: "redis://127.0.0.1:6379", expires: 300
  end
end
# Query the cache (It doesn't matter if this exists or not.)
puts cache[42].inspect
# Sleep 15 seconds. After 5 seconds, busy-loop will start.
sleep(15)

[asppsa]

Thanks very much for this report, and also for the repro. I'll take a look at this as a matter of urgency.

[asppsa]

@simmons I believe I have the issue fixed in #198 - I'm just trying to sort out the broken CI situation before I merge. In the meantime though, you might want to try out that branch for yourself to see if it fixes the issue for you.