match from waiting producer when possible.

[glycerine]

prevents premature termination when producers are waiting

[glycerine]

Also here is my own version from scratch. comments welcome.

(update), NOW OLD/IGNORE: gist.github.com/ponylang-gists/53f2ca1e746f28fc92753dea3e78c14c)

(update), NEW/IMPROVED:
https://gist.github.com/ponylang-gists/11523e64d3f11dcee275c62de0ff50ad

[SeanTAllen]

The formatting standard is 2 spaces. Please revert the last commit.

See https://github.com/ponylang/ponyc/blob/main/STYLE_GUIDE.md

[glycerine]

The formatting standard is 2 spaces. Please revert the last commit.

noted. corrected.

[glycerine]

the producer-consumer solution here is still buggy.

I wrote a little assertion file to test my solution (passed) and this solution (did not pass, at least 2 bugs detected). The specific failures can be studied on this branch, if anyone wants to spend time on it:

https://github.com/glycerine/ponyc/blob/still_borked_prodcons/examples/producer-consumer/buffer.pony#L56

Big picture, I would just suggest replacing it with my re-worked solution.

If that is acceptable, I can prepare a minimal version of it; it is here: https://github.com/glycerine/ponyc/blob/bench/examples/producer-consumer/fifo.pony

It not-- no harm, no foul.

The assertion file is here https://github.com/glycerine/ponyc/blob/still_borked_prodcons/examples/producer-consumer/assert.pony
I didn't want to thread TestHelper throughout the code, so this just uses C FFI to crash on assert immediately.

[glycerine]

I went ahead and put my rewrite here.

#4740

[SeanTAllen]

closing in favor of iterating on #4740.