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From Jeff Trawick <traw...@attglobal.net>
Subject Re: [PATCH] Fix POD reading...
Date Fri, 20 Jul 2001 14:34:13 GMT
Justin Erenkrantz <jerenkrantz@ebuilt.com> writes:

> > Of course, it isn't the prettiest thing to implement.  Here we're
> > using a socket call (apr_recv) on a pipe :)  Only the file code knows
> > it is a pipe.  You have to know it is a pipe to decide that rc==0 on
> > such a platform means EAGAIN.
> 
> How do we test for this in autoconf (unless we specify something in
> hints)?

pipe()
set read handle non-blocking
call read() on read handle of pipe

if rc=0, then this is Solaris^H^H^H^H^H^H^Ha platform which acts like
Solaris in this respect

> In the threaded MPM, since we're specifying a timeout and that sets 
> O_NDELAY (we're setting O_NONBLOCK as well), we're hitting the 

wow... (setting both)

> following clause in the Solaris read(2) manpage:
> 
>      When attempting to read from an empty pipe (or FIFO):
> 
>         o  If no process has the pipe open  for  writing,  read()
>            returns 0 to indicate end-of-file.
> 
>         o  If some process has the  pipe  open  for  writing  and
>            O_NDELAY is set, read() returns 0.
> 
>         o  If some process has the  pipe  open  for  writing  and
>            O_NONBLOCK is set, read() returns -1 and sets errno to
>            EAGAIN.
> 

wow again... maybe we should do O_NONBLOCK instead of O_NDELAY?

> Hmm.  And, this is tricky because we're referencing the POD as a socket
> not as a file in the threaded MPM.
> 
> And, if we switch the threaded MPM to use the mpm_common code (treat 
> it as a file), we're not notified when we have an incoming POD signal 
> (like we are when we treat it as a socket).  Ugh.  Maybe we could do 
> both?  Do the poll as a socket and read the POD as a file?  -- justin

I was thinking that we'd want to do the poll as a socket and read the
POD as a file.

-- 
Jeff Trawick | trawick@attglobal.net | PGP public key at web site:
       http://www.geocities.com/SiliconValley/Park/9289/
             Born in Roswell... married an alien...

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