Host implementation of pico_multicore

[jonathangjertsen]

It would be nice to have a host implementation of the multicore functionality which uses threads (or processes?) in place of the two cores.

I've started on an implementation here: https://gist.github.com/jonathangjertsen/590141bc17ffb47d0f091c6ab82396f3
The test uses the Unity framework. I haven't made a PR because there is a known bug (test_multicore_fifo_pop_timeout_us fails half the time and I don't know why), and also because I couldn't figure out how to integrate it into the pico-sdk build system. Feel free to build on it though.

[kilograham]

there is an implementation in pico_host_sdl that uses SDL

[kilograham]

https://github.com/raspberrypi/pico-host-sdl/blob/master/README.md

[jonathangjertsen]

Yes I saw, but it is incomplete (in particular, no FIFO support) and it would be nice to avoid having to pull in SDL if you're testing something other than audio/video.

[kilograham]

Yeah, i would probably have included threads by default were pthread available on windows; that said building with MSVC has issues anyway; not sure if there is a pthread impl for windows for use with gcc (or other)

(in particular, no FIFO support)

Frankly, we are discouraging the use of the FIFOs (for most things anyway) anyway, as they are a unique resource (needed by RTOS impls, core 1 launch, and interrupting the other core)...

[jonathangjertsen]

not sure if there is a pthread impl for windows for use with gcc (or other)

MinGW has it - not sure if it's included by default or if it has to be installed