[gclist] working with 64 bit ints/pointers

Stuart Yeates Stuart.Yeates@trimble.co.nz
Thu, 11 Dec 1997 13:00:06 +1300

> Mike exagerates a bit here, bit just a bit. Theoretically
> it is not precise, but practically speaking it is.
There are three flaws in the argument:
(a) things aren't uniformly distributed
(b) a pointer can be data too (consider especially programs such as
debuggers/tracers where much data is pointers. Depending on the memory
model in use, some pointers could be valid in both the client and the
debuggers address space but point to separate copies of
(c) type-safe garbage collectors often make optimizations (i.e. no
black-listing) that mean a single int/pointer confusion would have a
more drastic effect than in a well designed conservative collector

There are comparisons here with the Mars Rover story - if something has
a very small chance of happening, it's probably best to handle it
anyway. Does anyone have calculated vs apparent odds for the priority
inversion in the Mars Rover ? 

Stuart Yeates  --- stuart.yeates@trimble.co.nz
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