How do I use async programming in Perl?

Question

Is there a simple way to do async in Perl? I have the following logic for an Apache app:

get request
process request
write to log
return

what I want to do is to have the "write to log" part to be async, so that I can do the "return" part asap.

Answer 1

Unfortunately, this typically entails the POE framework, but there is also a growing alternative (which I would want to try first) called AnyEvent.

See this question for learning materials for more information about learning POE. POE is a framework and it tends to eat your whole application. It also doesn't look like Perl, and sticks out. I believe it is a big learning curve for your typical application.

AnyEvent is simple continuation based asyncronous tasking, you should be able to figure it out fairly well with just the CPAN docs.

For your specific question you would use AnyEvent's AIO or POE's Read Write wheel

Answer 2

Consider looking at Coro.

From its CPAN documentation:

Unlike the so-called "Perl threads" (which are not actually real threads but only the windows process emulation (see section of same name for more details) ported to unix, and as such act as processes), Coro provides a full shared address space, which makes communication between threads very easy. And Coro's threads are fast, too: disabling the Windows process emulation code in your perl and using Coro can easily result in a two to four times speed increase for your programs. A parallel matrix multiplication benchmark runs over 300 times faster on a single core than perl's pseudo-threads on a quad core using all four cores.

This includes Coro::AIO, a "truly asynchronous file and directory I/O", which might be what you're looking for.