Re: ANN: coxpcall 1.6 (was RE: Xavate crash and coxpcall missing 'arg' variable)

[Javier Guerra <javier@...>]

On 16 may 2005, at 8:11 PM, Romulo Bahiense wrote:

> > it certainly doesn't look like a bug in Lua code.  for me at least,  
> > LuaSocket is wonderfully stable; so it might be a compile or link  
> > issue.
>
> 	To resolve the problem I just renamed my lua5.dll and lualib5.dll to 
> liblua.dll and liblualib.dll, respectively.

glad to hear it's ok now :-)

> 	Now 2 semi-off-topic questions:
>
> 1) How does Xavante handle concurrency? eg: One user is uploading a 
> large file and another is browsing a web site hosted by the same http 
> server at the same time?

copas handles several coroutine-based 'threads'. these yield at any 
netwok I/O  long files are not a problem.

> 2) Would be difficult to implement an async request? e.g.: A very slow 
> request - like a database query returning many records - yelding 
> periodically to not block other requests.

that's far more difficult.  the first versions of luahttpd used 
preemptive multithreading with LuaThreads; but i knew coroutine 
switching is much faster than thread switching (even under Linux, but 
the breach is closing), so i wanted to first solve the http serving, 
and then move to a different structure, using far less threads and more 
coroutines.

when Andre showed me Copas, i decided to move luahttpd to run with it, 
eventually that became the main Xavante project.  I designed (and even 
managed to make it work) a weird 'thread under coroutine' that let any 
handler to spawn a new preemptive thread when needed, but I couldn't 
make i stable enough.  I think there's an issue with LuaThreads, 
especially between different versions of the Lua core.

Since LuaThreads is a very pervasive addition to Lua (and not a neat 
module, like LuaSocket), i decided to let it wait and try again when we 
have a final Lua5.1

I can send you the helper threads code, if you can compile a 
threads-capable lua core to test it.

in short: i'd love to have that too, but currently Xavante is _very_ 
fast for small queries (try Sajax!), so it can wait a bit


> 	Would it be too difficult to convince the author(s) of LuaSocket to 
> use the same DLLs from LuaBinaries?

he'll have to answer that himself...

--
Javier