coro

From the Coro intro docs- Using only ready, cede and schedule to synchronise threads is difficult, Coro supports a number of primitives to help synchronising threads in easier ways.

Those will just schedule the coro in their own scheduler, and perform the read again and continue.

We have generator functions (actually, first-class continuations and coroutines) via the Coro module.

Perl's Coro and Ruby's new(ish) fibers are examples of how that could look.

Python is in that respect essentially the same as Perl with Coro built-in.

You also seem very ill informed about Coro On the contrary, I've used it.

I see you didn't look into Coro or read much of what I said.

How many modules will expose coro based concurrency patterns?

Those are not needed in a coro-environment.

I think you misunderstand what working with Coro is like.

Basically when a coro starts, the contents of the stack pointer register are recorded, and when a coro wishes to switch, the slice of the stack from the recorded stack pointer value to the current stack pointer value is copied off onto the heap.

>> Alternatively, we could just yield the coro, waiting for a new special coroutine that would run in a background thread just executing readahead() and then re-scheduling(making runnable) the original coro, waiting for readahead.

Coro adds threading to Perl but falls short of being a concurrency practice- it's tooling for doing concurrency.

The only contenders there are Go, Haskell, and possibly some of the scripting language extensions (Python/Gevent, Perl/Coro).

I would be suspicious of anyone seriously trying to create a high volume Perl website using Coro.