Pat Maddox
4/2/2005 6:34:00 PM
In Java:
Socket s = new Socket();
s.connect(new InetSocketAddress(getHost(), port), timeout);
I can specify a timeout value for the connection, as you see above. I
don't see a way of doing that with the Ruby classes. I'm new to Ruby,
so I really don't know - is there a way to do it?
On Apr 2, 2005 11:14 AM, Sam Roberts <sroberts@uniserve.com> wrote:
> 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
> > > >
> > >
> > >
> >
>
>