[Vm-dev] Multiple images listening on same TCP port

[John M McIntosh]

Ok, I assume you did
> s := Socket newTCP.
> s listenOn: 7777.

in both images.

Yes Unix will allow that, this is not a squeak vm issue,

Check the socket options  to see if any apply to your needs of  
preventing two apps from acquiring the same socket
at the same time.


static socketOption socketOptions[]= {
   { "SO_DEBUG",				SOL_SOCKET,	SO_DEBUG },
   { "SO_REUSEADDR",			SOL_SOCKET,	SO_REUSEADDR },
   { "SO_DONTROUTE",			SOL_SOCKET,	SO_DONTROUTE },
   { "SO_BROADCAST",			SOL_SOCKET,	SO_BROADCAST },
   { "SO_SNDBUF",			SOL_SOCKET,	SO_SNDBUF },
   { "SO_RCVBUF",			SOL_SOCKET,	SO_RCVBUF },
   { "SO_KEEPALIVE",			SOL_SOCKET,	SO_KEEPALIVE },
   { "SO_OOBINLINE",			SOL_SOCKET,	SO_OOBINLINE },
   { "SO_LINGER",			SOL_SOCKET,	SO_LINGER },
   { "IP_TTL",				SOL_IP,		IP_TTL },
   { "IP_HDRINCL",			SOL_IP,		IP_HDRINCL },
   { "IP_MULTICAST_IF",			SOL_IP,		IP_MULTICAST_IF },
   { "IP_MULTICAST_TTL",			SOL_IP,		IP_MULTICAST_TTL },
   { "IP_MULTICAST_LOOP",		SOL_IP,		IP_MULTICAST_LOOP },
#ifdef IP_ADD_MEMBERSHIP
   { "IP_ADD_MEMBERSHIP",		SOL_IP,		IP_ADD_MEMBERSHIP },
   { "IP_DROP_MEMBERSHIP",		SOL_IP,		IP_DROP_MEMBERSHIP },
#endif
   { "TCP_MAXSEG",			SOL_TCP,	TCP_MAXSEG },
   { "TCP_NODELAY",			SOL_TCP,	TCP_NODELAY },
#ifdef SO_REUSEPORT
   { "SO_REUSEPORT",			SOL_SOCKET,	SO_REUSEPORT },
#endif
   { (char *)0,				0,		0 }
};



On 9-Jun-09, at 9:47 AM, Adrian Lienhard wrote:

> Hi,
>
> On the Mac VM, when starting a second image with the same VM as an  
> already running image, the second image opens the same TCP ports as  
> the first image.
>
> It is easy to see this. Start image A and do:
>
> s := Socket newTCP.
> s listenOn: 7777.
>
> as expected:
>
> lsof -i | grep Squeak
> Squeak    1747 adrian    9u  IPv4 0x9dafa68      0t0  TCP *:cbt  
> (LISTEN)
>
> Now, start image B (PID 1752).
>
> lsof -i | grep Squeak
> Squeak    1747 adrian    9u  IPv4 0x9dafa68      0t0  TCP *:cbt  
> (LISTEN)
> Squeak    1752 adrian    9u  IPv4 0x9dafa68      0t0  TCP *:cbt  
> (LISTEN)
>
> It will also listen on port 7777...
>
> Is this a known limitation?
>
> VM: 3.8.20beta1U
> Image: any (tested with Squeak 3.9 and 3.10)
>
> Cheers,
> Adrian
> ___________________
> http://www.adrian-lienhard.ch/
>

--
= 
= 
= 
========================================================================
John M. McIntosh <johnmci at smalltalkconsulting.com>   Twitter:   
squeaker68882
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
= 
= 
= 
========================================================================