[Qt-interest] need input on shared memory/communication

[Paul Miller]

I'm looking into schlepping memory from one process to another use some 
kind of on-demand shared-memory/IPC solution (on Mac OS X):

App 1 has a large amount of data (100-200MB) available, and LAUNCHES App 2

App 2 requests certain chunks of the data from App 1, and then later 
sends certain chunks of data back to App 1 - the order and size of the 
chunks of data are defined at runtime and are not constant

Is this feasible to implement using Qt's shared memory classes and some 
kind of IPC message system?

The "dumb" non-IPC way to implement this would be for App 1 to write 
it's large amount of data to a temporary (possibly memory-mapped) file, 
THEN launch App 2. App 2 would then request certain chunks of data which 
would just be read from the file. Then later it would write to the file, 
App 2 would exit, and App 1 would read the changes from the file.

I'd like to use a cleaner solution that isn't so wasteful of disk space. 
Also, App 1 can do certain performance-related things on the requested 
data that I would have to move into App 2, and I'd like to avoid that.

Any suggestions? The Qt sample shared memory app doesn't address the IPC 
or large-buffer-size aspects of what I need to do.