OpenEuphoria

Re: Threads [Was: Re: 64 bit euphoria]

• Posted by Jason Gade <jaygade at yahoo.com> Apr 28, 2005
• 509 views

<snip much talk about threads>

First let me say that I really don't think that Euphoria needs threads.  I don't
believe that the language needs the extra complication.

Any program that needs simulated threads instead of multiple processes can make
an event loop and set up either round-robin or timer callbacks.

> codepilot Gmail Account wrote:
> <large snip>
> > Well mabey
> > 
> > for doc = 1 to length(documents_to_parse) do
> > --doEvents won't get called but once each document
> > for character = 1 to length(documents_to_parse[doc]) do
> > --doEvents would get called way too offten, for each character,
> > majorly slowing down the parsing
> > end for
> > end for
> > 
>

I'm not sure what doEvents does, but I wouldn't do it this way.

Write your parser so that it operates on say 10 words at a time (or whatever is
a convenient size of work in a timeslice without slowing things down) and then
return (or do_events) at the end of that amount of work.  When all the work is
done set a flag and don't do anymore work!

But if euphoria had threads, I would implement it like this:

start_thread(routine_id(new_thread)) -- Start a new thread procedure
Tlock() -- Called by threads in order to pause all other threads while accessing
shared/global variables
Tunlock() -- Unpause threads

-- I don't know enough about semaphors and messaging yet.  Could probably be
done with a combination of Tlock(), Tunlock() and a global variable(s).

end_thread() -- Called by thread when its work is done; removes it from the
queue

kill_thread(routine_id(old_thread)) -- used by the main process to remove a
thread that doesn't end itself

I think that this could be written in a library that simulates the threads (like
Langwar) instead of directly in the language.  And of course you wouldn't have to
worry about orphaned threads if your main process died.



=====================================
Too many freaks, not enough circuses.

j.