Hi Thomas, Now that I can run your async reading and writing code.
would you be able to tell me what all the arguments to the functions in nb.l actually are. I mean what are they used for not just data type, as I can't say i fully follow it beyound that the first argument to rdx is a list beign used as a buffer. regs Konrad 2008/10/10 Tomas Hlavaty <[EMAIL PROTECTED]>: > Hi Alex, > >> The drawback of implementing such a fully non-blocking system will >> be that the present separation of event generation (select) and data >> processing (read) cannot be held up any longer, and a completely >> different application flow is required. > > yes, indeed. > > I attach a simple non-blocking echo server. There are some functions > in C just to get the C read & write functions and some blocking stuff > up to the picolisp level. Then the echo server waits for events on a > socket and writes back what it read. > > Conceptually it should not block, I am not sure how to test it though. > Any ideas? > > There are some things that could be done better, like: > > - the buffer could be circular and support for this could be in the C > functions rdx and wrx. > > - buffer could be local for the sockets, so 'callback' should be a > closure... I guess I would have to use 'job' but that's next lesson > I have to look at:-) > > It might be nice to build some kind of abstraction above this low > level, non-blocking code. Maybe to implement continuations to > abstract away the event driven code. Not sure how difficult it would > be in picolisp. > > There should really be -m32 switch in the 'gcc' function. It would > also be useful if it would be possible optionally switch on -g without > having to modify the gcc.l file. > > Cheers, > > Tomas > > > (cd (pack (sys "HOME") "/picolisp")) > (load (pack (sys "HOME") "/src/picolisp/nb.l")) > > # (out "/tmp/a" (wrx '(1 2 3 4) 4)) > # (out "/tmp/a" (wrx '(1 2 3 4) 3 1)) > > # (setq *B (need 5)) > # (in "/tmp/a" (rdx *B 3)) > # (in "/tmp/a" (rdx *B 2 3)) > # *B > > # non-blocking echo server > > (setq *N 5) # try bigger buffer;-) > (setq *B (need *N)) > (setq *I 0) > (setq *J 0) > > (set 'EAGAIN (eagain)) > > (de _rdx (Sock) > (in Sock > (let? N (rdx *B (- *N *I) *I) > (when (gt0 N) > (inc '*I N)) > N))) > > (de _wrx (Sock) > (out Sock > (let? N (wrx *B (- *I *J) *J) > (when (gt0 N) > (inc '*J N)) > N))) > > (de callback (Sock) > (let End NIL > (prinl "callback " Sock " J=" *J " I=" *I " N=" *N) > (block Sock NIL) # first time would be enough > (unless End > (let N (_rdx Sock) > (prinl " read " N) > (unless (or (gt0 N) (= N 'EAGAIN)) > (setq End (cons rd N))))) > (unless End > (let N (_wrx Sock) > (prinl " written " N) > (unless (or (gt0 N) (= N 'EAGAIN)) > (setq End (cons wr N))))) > (when End > (prinl " finish") > (task Sock) > (close Sock)) > (when (<= *I *J) > (prinl " rotate J=" *J " I=" *I " N=" *N) > (setq *I 0) > (setq *J 0)) > (prinl "end " Sock " J=" *J " I=" *I " N=" *N))) > > (task (port 4444) # Listen on port 4444 > (when (accept @) # A connect arrived > (task @ # Install another task on this socket > Sock @ # Keep the socket in the task's env > (callback Sock) ) ) ) > > -- UNSUBSCRIBE: mailto:[EMAIL PROTECTED]
