•Understanding
resource contention between RTSJ hard real-time components and firm real-time components requires detailed understanding of RTSJ implementation choices
(not necessarily
documented)
•Care must be
taken to properly manage immortal buffers shared between hard and soft real-time without using
direct synchronization
–Absence
of synchronization not enforced statically or dynamically
–Wait-free queues require information copying and/or
dynamic buffer management
and design of ad hoc throttling techniques
•Performance
penalties:
NoHeapRealtimeThread implements read and write barriers, RealtimeThread implements different write barrier, to enforce “isolation”
strategy
3 Different
Models of Execution