Guidance on use of Socket

> Hi John,
>
> John Thornborrow wrote:
>
>> I'm trying to create a simple listening service on localhost port 3456,
>> I assumed this would wait for 30 seconds, then proceed but it singals
>> ConnectionClosed error at the #waitForDataFor: message:
>>
>> | sock |
>> sock := Socket new.
>> sock listOn: 3456.
>> sock waitForDataFor: 30.
>
> You need to wait for a connection with an additional method
> waitForAcceptFor: So your code should be something like:
>
>  sock := Socket new.
>  sock listOn: 3456.
>  connSock := sock waitForAcceptFor: 100. "100s"
>  connSock notNil ifTrue: [connSock waitForDataFor: 30].
>
> This will trigger once. If you want more, you need to put above in
> loops. Something like:
>
>  sock := Socket new.
>  sock listOn: 3456.
>  [true] whileTrue:
>     [connSock isNil whileTrue:
>     [connSock := sock sock waitForAcceptFor: 100].
>     data := connSock waitForDataFor: 30.
>     "process here that data"]
>     connSocket close].
>
> But if you want simpler sockets, I recommend you to use SpSocket from
> Sport portability library. Look for it on SqueakMap, Universes or
> SqueakSource.
>
> I hope this helps a bit.
>
> Janko
>
>

>
> On Dec 28, 2007, at 10:44 AM, Janko Mivšek wrote:
>
>> And I managed to make a mistake or two in below code. But you'll
>> probably find it by yourself :)
>
>
>
> Well and a few other hints...
>
> (a) when someone sends you say 10 bytes of data, when those 10 bytes of
> data will arrive occurs
> sometime between now and the future. A classic mistake is doing a read
> and thinking you've gotten
> all the data... However you might find that last byte (well frame
> actually) is wandering about in some router still...
>
> (b) when you send data, then close the socket before checking to see if
> all the data is sent, the logic if it's
> set to Socket Linger will attempt to send the data, but after 2 seconds
> will abort and not actually have sent all
> the data.  Usually this is *much* more apparent when you have an
> application that does a send of 64k of
> data then close the socket and you are using a dialup connection.
>
>
>
> --
> ===========================================================================
> John M. McIntosh <[hidden email]>
> Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
> ===========================================================================
>
>
>
>