On Tuesday, 13 September 2016 at 18:24:26 UTC, deadalnix wrote:
No you don't, as how often the GC kicks in depend of the rate
at which you produce garbage, which is going to be very low
with an hybrid approach.
This is simply not true.
Assume in a pure GC program the GC heap can grow up to X Mb
before a collection cycle happens, which has to scan X Mb of
memory.
Now let's say we have a hybrid program that uses 0.5X Mb of RCed
memory and 0.5X Mb of GC memory so the total memory consumption
is still X Mb. When the GC heap reaches 0.5X Mb, it has to scan
both RC and GC memory.
It's quite obvious that the time(t) it takes for program 1 to
produce X Mb of garbage is the same as program 2 to produce 0.5X
Mb of garbage, and after time t, both program have to scan X Mb
of memory. However program 2 also has to pay the cost of
reference counting on top of that.
When you say hybrid program should trigger GC at a lower rate,
you are actually assuming the hybrid program also has X Mb of GC
heap, which makes total memory consumption 1.5X Mb, therefore it
is not a fair comparison anymore.
