[Interest] single application

[Duane]

I have an application that runs on both Windows and Linux.  To prevent 
multiple instances, we are using QSingleApplication.  On Windows, if the 
app is started from the desktop this works fine but if it's started from 
a console a second instance can be started.

So I've decided to try a suggestion using QSharedMemory.  I create an 
instance of QSharedMemory with a unique key in main.  Then if I can call 
create() and it succeeds there is only one app running.  This works fine 
in windows.  It works fine in Linux as long as the running app doesn't 
crash.  Then the shared memory object is not released and no future 
instances can be created until a reboot.  This is described in the help 
for QSharedMemory.

I would like to use the same method for both OS and also, we expect to 
go to Qt 5 and QSingleApplication, QServices etc don't seem to be supported.

Is there some cross platform way to achieve this and one that will be 
supported by Qt5?