From: Seth Kurtzberg <seth@...>
Date: 2003-02-27T17:27:26+09:00
Subject: Re: Unable to do non-blocking read on socket

The read call is already preceded by kernel#select(), but that doesn't help.  
kernel#select() tells me that data is available to read, but it doesn't stop 
IO#read() from blocking if it's buffer size is larger than the amount of data 
available to read.

On Thursday 27 February 2003 01:24 am, Mauricio Fern�ndez wrote:
> On Thu, Feb 27, 2003 at 05:03:37PM +0900, Seth Kurtzberg wrote:
> > I have not been able to change the behavior of IO::read() to
> > non-blocking. Calling the fcntl method and setting the NONBLOCK flag
> > (and/or the NDELAY flag) has no effect on the behavior of IO::read().
> >
> > This is on a socket.  IO::recv() does not block; however, I can't use
> > IO::recv() because I have already used a buffered read method on the file
> > descriptor.  This causes an exception, not just the unpredictable
> > behavior suggested in the documentation.
> >
> > More precisely, if running with the debugger, an exception occurs stating
> > that a previous buffered read has occured on the stream.  If running
> > normally (without the debugger) an exception occurs stating "wrong number
> > of arguments (5 for 4)" during the IO#read() call, which is odd as the
> > method takes only one parameter and a second optional parameter. 
> > Presumably the exception occurs somewhere down the stack; as the method
> > name is not displayed and the behavior changes if the debugger is used,
> > it is rather difficult to know what is going on.
> >
> > In any event I need to be able to do a read that doesn't block.
>
> Kernel.select ?
> Not really what you're asking for, but...

-- 
Seth Kurtzberg
M. I. S. Corp.
480-661-1849
seth@cql.com