Threads workaround

[ghost]

Hello, not sure if this an issue or pull request, here I go: First, thanks for making this project open source, not only that, it is beautifully documented.

I am trying to run pachi in a javascript environment using emscripten. Compilation is OK, but thread related functions are not defined.

If I understand correctly, the only workaround is modifying the source code and avoid threads.

I would like to invest my time on this; do you think is possible?, do you have any recommendation?.

Thanks and again; awesome project!.

[pasky]

Hi! Until we have a patch, let's call this an issue. :-)

I'm glad you like Pachi! Running it in Javascript could be fun, though Pachi probably will not be very strong, especially single threaded. (By the way, take a look at Michi if you would like to think about implementing a Go program in Javascript from scratch.)

What you seek to do should not be very difficult, though it's not totally trivial either. I'm just not sure how to do it in a way that would be mergeable back to the main codebase.

First, take a look at the comment "Pachi threading structure:" in uct/search.c. Basically, you will want to just run a single worker (uct_playouts()) in uct_search() instead of the whole threads machinery, and modify the uct_playouts() to call uct_search_check_stop() time by time (not on every iteration, it's not entirely cheap check). Shouldn't be too hard.

(Or if you'd like to avoid touching uct_playouts(), you could do something crazy like set up a timer with timer_start() which will call the uct_search_check_stop() periodically. That might make this easier to merge back. But I don't know if that can be handled by emscripten, and if it won't end up being too horrid (or way too slow in emscripten) anyway.)

Good luck!

[ghost]

Pachi is working on Node! (without threads of course ^^). Strangely though, I couldn't get Pachi to work on the web environment yet. There is a problem when allocating a board struct:

Uncaught abort("Assertion failed: undefined") at Error
    at _board_copy (file:///D:/pachi/pachi.js:8470:8)

I will keep on trying to fix this, any comment is welcome ^^.

Thanks for all the time and help,

[ghost]

Update: Pachi is working on web environment too!, Yay!, I love Pachi :D.

Thanks for the guideline Pasky, you really told me how to do it :).

[pasky]

Glad that helped :)