Quoting pergesu / gmail.com, on Sun, Apr 03, 2005 at 02:03:51AM +0900:
> I don't want to override the protocol's idea of a timeout - I'd like
> some means of specifying a timeout for the connection though.  In
> every other language I've used, I can set a timeout value on the
> socket itself.  It doesn't look like that's the case in Ruby.  Is

The C, perl, and Java networking APIS don't support timeouts on TCP
connect(), and the C/BSD sockets API is what most (all?) other languages
use internally.

Out of curiosity, what are these languages?

> there a method somewhere in the Socket classe heirarchy that lets me
> specify a timeout?
> 
> According to timeout, you can set an Exception that gets thrown when
> it times out.  I set that to StandardError, and just handle

Not sure what you mean. You can make timeout raise errors other than
Timeout::Error, and catch them, but you don't do so in the example you
posted.

> StandardError at the end.  According to the docs, Timeout::Error can't
> be used with rescue because it doesn't inherit from StandardError.

I assure you that Timeout::Error can be caught by rescue, as I showed, I
do it quite often and it works fine.

> I'd still like some means of setting a timeout value for a socket
> connection.  That's a pretty basic aspect of the protocol, there's no
> reason it shouldn't be in there.

I see no evidence that user configurable timeouts on connect() are not
part of the TCP protocol.

Cheers,
Sam

> On Apr 2, 2005 9:37 AM, Sam Roberts <sroberts / uniserve.com> wrote:
> > Quoting pergesu / gmail.com, on Sat, Apr 02, 2005 at 08:05:15PM +0900:
> > > I'm writing a little method that just tries to open a tcp socket
> > > connection, then closes it off.  I'm using timeout to limit the amount
> > > of time it tries to connect (is there a better way?).  If it times
> > 
> > I have to wonder why you want to override the TCP protocols ideas of a
> > timeout. The protocol designers and implementors have a pretty good idea
> > of what  the timeouts should be.  If its not fast enough for you, you
> > probably want too much.  Doing this will make your code flaky and
> > unreliable when the network isn't as fast as your local network. A good
> > text on network programming should explain this. If you are finding your
> > app is blocked, you can use ruby threads to do connections in the
> > background.
> > 
> > That said, you can't catch exceptions like that, try:
> > 
> > begin
> >   Timeout::timeout(3) do
> >      long running op
> >   end
> > rescue Timeout::Error
> >   p "hi"
> > end
> > 
> > Sam
> > 
> > > out, I just want to say that the connect failed.  Despite catching the
> > > Timeout::Error (I think, anyway), I always get the Exception output.
> > > First, here's the method:
> > >
> > >       def execute
> > >               status = timeout(@timeoutval) {
> > >                       socket = TCPSocket.new(@host, @port) rescue false
> > >
> > >                       socket.close if socket
> > >                       return socket != false
> > >               } rescue Timeout::Error
> > >
> > >               return false
> > >       end
> > >
> > > And now the output from my unit test:
> > >
> > > Started
> > > /usr/local/lib/ruby/1.8/timeout.rb:42:in `new': execution expired
> > > (Timeout::Error)
> > >         from ./PortHostTest.rb:16:in `execute'
> > >         from ./PortHostTest.rb:15:in `timeout'
> > >         from /usr/local/lib/ruby/1.8/timeout.rb:55:in `timeout'
> > >         from ./PortHostTest.rb:15:in `execute'
> > >         from ./HostTest.rb:10:in `runTest'
> > >         from ../tests/test_HostTest.rb:14:in `test_simple'
> > >         from /usr/local/lib/ruby/1.8/test/unit/testcase.rb:70:in `__send__'
> > >         from /usr/local/lib/ruby/1.8/test/unit/testcase.rb:70:in `run'
> > >          ... 10 levels...
> > >         from /usr/local/lib/ruby/1.8/test/unit/autorunner.rb:194:in `run'
> > >         from /usr/local/lib/ruby/1.8/test/unit/autorunner.rb:14:in `run'
> > >         from /usr/local/lib/ruby/1.8/test/unit.rb:285
> > >         from /usr/local/lib/ruby/1.8/test/unit.rb:283
> > >
> > 
> >
>