wine users - Mar 2011 - Accessing shared memory

I have a Windows based application that was written by my customer.   This
application receives data via UDP, massages the data(proprietary algorithm),
then stuffs the output into a shared memory segment.  This app runs perfectly
using Wine on my Linux box(Fedora 12).

My own development environment is Java.  I need to write a piece of native C
code that can get at the shared memory segment that is created by my
customer's application using shmat().

Does anyone have any idea how to tackle this issue?

On Tue, 2011-03-29 at 17:04 -0500, holtrk85 wrote:
> I have a Windows based application that was written by my customer.
> This application receives data via UDP, massages the data(proprietary
> algorithm), then stuffs the output into a shared memory segment.  This
> app runs perfectly using Wine on my Linux box(Fedora 12).
> 
> My own development environment is Java.  I need to write a piece of
> native C code that can get at the shared memory segment that is
> created by my customer's application using shmat().
> 
> Does anyone have any idea how to tackle this issue?
> 
Sounds like you'll need to use the JVM's JNI API. See your JDK's
documentation set for the JNI documentation.

Have you and your customer considered using a socket rather than shared
memory to pass information between the programs? That is generally an
easier interface to manage when Java needs to talk to a program written
in another language. You don't say whether your code will always run
under Linux or if it is intended to run in a Windows environment in
future. If the latter you're definitely better off using sockets because
the C code used to write the JNI extensions to the JVM is OS-specific,
so it will not be portable between Linux and Windows.

This thread appears more to do with Java than Wine, so I suggest you
post any additional questions on comp.lang.java.programmer rather than
here.


Martin

holtrk85 wrote:
> Does anyone have any idea how to tackle this issue?
This is not java forum, you'll have to ask google about how to access shared
memory from java on windows. Of course your program will have to run within Wine
itself.

Accessing this shared memory from outside of Wine is not possible, unless you
are super user (root), or using some special tricks (that won't work on Wine
itself). On all *NIX systems no process can assess other processes' memory,
with few exceptions (ex debugger).