lCertain cross-heap pointers are illegal
–User-user
pointers are illegal
–
lUse GC “write barrier” to enforce
–Check heaps on
every write
–Throw
SegmentationViolationError if illegal
–
lSmall cost on legal write (common case)
–Microbenchmarks
(tight loop, hot cache)
»41 cycles
without memory overhead
»25 cycles with
slight memory overhead