ported nallocx support from Google-internal tcmalloc
nallocx is extension introduced by jemalloc. It returns effective size
of allocaiton without allocating anything.
We also support MALLOCX_LG_ALIGN flag. But all other jemalloc
flags (which at the moment do nothing for nallocx anyways) are
silently ignored, since there is no sensible way to return errors in
this API.
This was originally contributed by Dmitry Vyukov with input from
Andrew Hunter. But due to significant divergence of Google-internal
and free-software forks of tcmalloc, significant massaging was done by
me. So all bugs are mine.
4 files changed
