Summary:
Secondary backed allocations do not require a cache. While it's not necessary
an issue when each thread has its cache, it becomes one with a shared pool of
caches (Android), as a Secondary backed allocation or deallocation holds a
cache that could be useful to another thread doing a Primary backed allocation.
We introduce an additional PRNG and its mutex (to avoid contention with the
Fallback one for Primary allocations) that will provide the `Salt` needed for
Secondary backed allocations.
I changed some of the code in a way that feels more readable to me (eg: using
some values directly rather than going through ternary assigned variables,
using directly `true`/`false` rather than `FromPrimary`). I will let reviewers
decide if it actually is.
An additional change is to mark `CheckForCallocOverflow` as `UNLIKELY`.
Reviewers: alekseyshl
Reviewed By: alekseyshl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35358
llvm-svn: 307958
b44364dd15