[Axiom-developer] Re: Bug in AXserver.spad

[Alfredo Portes]

Hi Tim,

I found a good and bad solution:

The good is that the following code fixes the issue. There is
no hanging and the pages display properly.

  multiServ(s:SExpression):Void ==
        WriteLine("multiServ begin")$Lisp
        headers:String := ""
        char:String
        -- read in the http headers
        flag:Integer := 1
        length:Integer := 0
        while flag > 0 repeat
          char := STRING(READ_-LINE(s,NILL$Lisp,'eof)$Lisp)$Lisp
          length := LENGTH(char)$Lisp
          if length = 1 then
            flag := 0
          else
            headers := concat [headers,char]
          --WriteLine$Lisp "Header: "headers

The bad, this for some reason breaks the POST requests. The line
containing the command is never reached (last line). Maybe you
can take a look at my really bad code and fix it :-).

>  and nothing else when sent from a remote machine. I modified the
>  read-char-no-hang loop to print out each character and it gets
>  nothing from the stream. Thus stream creation is broken in GCL.

I think you only see the problem if you use:

read-char-no-hang

with

read-char or read-line, you will see that you always get something
from the stream.

>  Or if the remote request is successful we get a normal request
>  followed by a series of #xFF characters.  Apparently there is not an
>  agreement about the EOF character. This causes Axiom to loop looking
>  for EOF. I inserted code to check for this condition. Thus EOF
>  checking is broken in GCL.

You are absolutely right. I couldn't figure out what the end line is.
So by looking
at the output of the last line, it is a string of length one (not sure
what it is). So
I make the loop stop when I see that.

>  To make the remote request succeed you simply need to hammer on
>  the link very fast for a while and the request will get thru.

Yes.. :-) sometimes you dont have to hammer it and just press enter long enough
(you have to be very precise).

>  However, that raises another problem that the XMLHttpRequest objects
>  can hang. I wrote some javascript code to do a timer pop if I get no
>  response. Once there is an outstanding XMLHttpRequest that does not
>  get a response then the connection is permanently hung.

>  All of this code works perfectly if you browse from the local machine.

Yes it does. I still blame the the read-char-no-hang. You can see that
it works if
you use another function. And with the lisp code it works fine. I
guess this is a good
indication that the sockets in GCL work fine.