Socket timeout not working with libUrl

Alex Tweedly alex at
Mon Jan 31 05:41:38 EST 2005

Frank Leahy wrote:

> After a lot of testing on Mac OS X, I've found that the problem I was 
> having appears to be due to the way that Mac OS X does DNS lookups.  
> Whether or not it's a RunRev bug as well is hard to tell, but I think 
> it might be.
> Here's some sample code I wrote.  This code sends a "My5SecondTimeout" 
> message to itself, opens a socket, makes an HTTP GET request, waits 
> for the response, and closes the socket.  (Note: I had to use this 
> "My5SecondTimeout" message because setting the socketTimeoutInterval 
> doesn't seem to work).
> When you run this script and you're not connected to the internet 
> here's what happens:
>    1) If I open the socket with an ip address, e.g., my 
> 5 second timer will fire, and I can close the socket and exit from the 
> routine.
>    2) If I open the socket with a domain address, e.g. 
>, Mac OS X does a DNS lookup, puts up the rainbow 
> rotating color cursor, and hangs until the DNS lookup fails.  On my 
> machine this takes 60 seconds (apparently it's dependent on how many 
> dns servers you have listed).
> I'm guessing this is a RunRev bug, but I can't be sure.  Basically 
> RunRev hangs for 60 seconds while the DNS lookup takes place during 
> the "open socket" call -- it doesn't send a socket timeout, and it 
> doesn't the "My5SecondTimeout" message either.
> Can confirm this?


you may have missed the email I sent earlier in this thread, re bug 2117 
Engine blocks on DNS query

Take a look at that bug report for more details. You can check for 
dnsservers - which will prevent the problem occurring in most cases, but 
there are still some cases where it will fail.

-- Alex.

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