Major Difficulties (cont’d)
Communication middleware (3.5 PY)
- Portals 2.0 in Linux (6 PM)
- No API
- Data structures in user space
- Protection boundaries have to be crossed to access data structures
- Data structures have to be copied, manipulated, and copied back
- Requires interrupts
- Address validation/translation on the fly
- Incoming messages trigger address validation
- Doesn’t fit the Linux model of validating addresses on a system call for the currently running process
- Developed Portals 3.0 API (1 PY)
- Implemented Portals 3.0 (1 PY)
- Transition from P2 to P3 (1 PY)