Shared memory and permissions

[helios]

Would it be possible for a creation of shared memory to fail because the process has insufficient permissions?

Also, is it possible to create a shared memory that's only process-local? In case you're wondering what the point of a process-local shared memory would be, I need to share information between two pieces of code that have no way of interacting with each other, other than by agreeing at compile time on a particular string.

[mbozzi]

Would it be possible for a creation of shared memory to fail because the process has insufficient permissions?

Yes! At least if you use the method I link below.

Also, is it possible to create a shared memory that's only process-local.

I think you need to create a private object namespace
https://docs.microsoft.com/en-us/windows/win32/sync/object-namespaces
And then create a named file mapping object in that namespace
https://docs.microsoft.com/en-us/windows/win32/memory/creating-named-shared-memory
https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-createfilemappinga

[helios]

Thanks. It seems like it would add more complexity than I'd like, though. A shared memory under Local\ will do. I'm primarily concerned with reliability. I don't want to introduce possible weird failure modes.