Dear list,
I believe that there is a little issue in
the garbage collector implementation that was there all along at least
since 5.1. This issue (at least this occurrence) does not affect
stability and should have rather little performance impact, but I think
it's worth fixing anyway, once confirmed.
Please
consider a table with present array part and absent hash part. If I
understand correctly, in this case Table.lsizenode will be equal to zero
and no Node vector will be allocated. In this scenario, the memory
footprint of such table will be equal to
sizeof(Table) + sizeof(TValue)*h->sizearray
However, during the footprint computation in traversetable, another part is added, related to hash vector, which is
... + sizeof(Node) * cast(size_t, sizenode(h))
The thing is, even with lsizenode equal to 0, sizenode(t) will return
( twoto((t)->lsizenode) ) == ( 1 << ((t)->lsizenode) ) == ( 1 << 0 ) == 1
thus erroneously adding sizeof(Node) to the return value.
To my mind, it could've been fixed by re-implementing sizenode:
#define sizenode(t) ( (t)->lsizenode ? twoto((t)->lsizenode) : 0 )
Please take a look.
--
Best regards,
Igor A. Ehrlich
