localhost udp bind: address in use

[Michael D. Berger]

I have some complex multi-thread C++ code in which I do
some internal signaling with udp sockets:
snd: 127.0.0.1:6501
rcv: 127.0.0.1:6502

On my new F15_64 box, I usually get:
errno=98=Address already in use
in response to the bind command when I bring up the snd
socket (which is first up) even when I just come up from
power off.

Rarely, it works. I have no idea why.

If I ignore the 98 error, I get a write error on the socket.

Even when it fails,
netstat -uap
shows the socket, which is not a surprise, and it
is not there when the program is not up.

Now on my old CentOS 5_32 box, the same code
(but, of course, compiled for 32) works with no
problem. I can start and stop it rapidly with no
problem.

Thanks for your suggestions.
Mike. 
--
Michael D. Berger
[e-mail]
http://www.rosemike.net/

[Christopher K. Johnson]

Is ipv6 enabled?

Any chance it is binding to loopback using an ipv6 loopback address, and 
then finding it is already bound using the ipv4 equivalent?

On 10/31/2011 09:20 PM, Michael D. Berger wrote:
> I have some complex multi-thread C++ code in which I do
> some internal signaling with udp sockets:
> snd: 127.0.0.1:6501
> rcv: 127.0.0.1:6502
>
> On my new F15_64 box, I usually get:
> errno=98=Address already in use
> in response to the bind command when I bring up the snd
> socket (which is first up) even when I just come up from
> power off.
>
> Rarely, it works. I have no idea why.
>
> If I ignore the 98 error, I get a write error on the socket.
>
> Even when it fails,
> netstat -uap
> shows the socket, which is not a surprise, and it
> is not there when the program is not up.
>
> Now on my old CentOS 5_32 box, the same code
> (but, of course, compiled for 32) works with no
> problem. I can start and stop it rapidly with no
> problem.
>
> Thanks for your suggestions.
> Mike.
> --
> Michael D. Berger
> [e-mail]
> http://www.rosemike.net/

[Michael D. Berger]

> -----Original Message-----
> From: [e-mail] 
> [mailto:[e-mail]] On Behalf Of 
> Christopher K. Johnson
> Sent: Monday, October 31, 2011 22:25
> To: Community support for Fedora users
> Subject: Re: localhost udp bind: address in use
>
> Is ipv6 enabled?
>
> Any chance it is binding to loopback using an ipv6 loopback 
> address, and then finding it is already bound using the ipv4 
> equivalent?

[...}

I disabled ipv6 in /etc/modprobe.d/ and verified gone with:
   lsmod | grep -i v6
but the problem is not fixed.

Thanks,
Mike.

--
Michael D. Berger
[e-mail]
http://www.rosemike.net/

localhost udp bind: address in use -- Solved

[Michael D. Berger]

This tuened out to be a coding problem uncovered
by migrating to a much faster box.
Briefly, the initial call to the getInstance()
of a singleton was not complete before a
second, higher proirity call was issued.

Sorry for the distraction.
Mike.
--
Michael D. Berger
[e-mail]
http://www.rosemike.net/