Re: Ada Operating System

[Darren New <dnew@san.rr.com>]

Actually, I think there's another way that an Ada-based OS could be
superior to a C-based OS. Imagine an OS where all IPC is done via
message passing of messages between queues. That is, when you (for
example) want to read a file, you put the file handle and the "read"
token at the start of a buffer, pass the buffer to the queue for the
file system thread. The file system thread wakes up, fills up your
buffer, and passes it back to you. In a protected-memory system, it
would be helpful if said buffers were always allocated on page
boundaries, with at most one buffer per page, so simple memory-map
manipulations could move the buffer from one address space to the other. 

Would an Ada compiler (perhaps aided and abetted by the linker) be able
to take objects of the "Message" generic (or tagged) type and assure
they're always allocated on page boundaries, and objects of the "Queue"
generic (or tagged) type are always in pages together (so the OS knows
where they are perhaps) in a way that would be tedious and error-prone
in C? Could it be done with appropriate storage pools, so it doesn't
even really need to be specialized in the compiler?

-- 
Darren New 
San Diego, CA, USA (PST). Cryptokeys on demand.
      Remember, drive defensively if you drink.