IPC not configured

IPC not configured

[Darryl Scott]

Hi!

I have recently been starting to use cygwin on a Windows 2003 server. The 
UNIX code has been ported using Interix, windows services for UNIX. This 
does not come with an X-server.

The port has been very straightforward. The single user X applications work 
A-OK. I am having problems with the multi-user versions which make use of 
IPC. When I try starting say message queues within cygwin and check with 
ipcs the system states that the kernel has not been configured for IPC.

IPC started via c-shell in Interix are active and X-apps in cygwin start 
and put a message on to a queue, the other end of the queue is not read and 
so the app hangs.

If anyone could point me to documentation I will be delighted.

Thank you in anticipation

Darryl

Re: IPC not configured

[Harold L Hunt II]

Darryl,

Darryl Scott wrote:

> Hi!
> 
> I have recently been starting to use cygwin on a Windows 2003 server. 
> The UNIX code has been ported using Interix, windows services for UNIX. 
> This does not come with an X-server.

Okay, is your ported code in these examples still being run under 
Interix, or has it been recompiled under Cygwin?  I am thinking Cygwin, 
but I want to make sure.

> The port has been very straightforward. The single user X applications 
> work A-OK. I am having problems with the multi-user versions which make 
> use of IPC. When I try starting say message queues within cygwin and 
> check with ipcs the system states that the kernel has not been 
> configured for IPC.

The cygipc package in Cygwin provides IPC support.  It has to be started 
manually.

> IPC started via c-shell in Interix are active and X-apps in cygwin start 
> and put a message on to a queue, the other end of the queue is not read 
> and so the app hangs.

That sort of integration between the IPC system in Interix and the IPC 
system in Cygwin is unlikely to work.  I don't believe that cygipc is 
using Windows' IPC mechanisms, so Interix would have no knowledge of 
what is going on in cygipc, etc.  At least, I suspect that is how it is 
implemented, but I could be wrong.

> If anyone could point me to documentation I will be delighted.

Here is Chuck Wilson's documentation:

http://www.neuro.gatech.edu/users/cwilson/cygutils/cygipc/

Here is the readme for cygipc:

http://www.neuro.gatech.edu/users/cwilson/cygutils/cygipc/#README


Do note that the cygipc package will be dropped in favor of the new 
cygserver application that works in conjunction with function stubs in a 
new version of cygwin1.dll.  That will allow all Cygwin apps to be 
compiled with IPC support and to only enable it when cygserver is 
running.  That change will require a recompile of all apps that use IPC, 
I believe.

Harold