This operation is short-hand notation for rebuilding
a hash table. This rebuild can occur in the presence
of concurrent readers and will require twice the amount
of memory of the existing hash table until completion.
This borrows from a technique described by Purcell and Harris
in "Non-blocking hashtables with open addressing" technical report.
Essentially, every slot will have an associated local probe maxim,
including tombstones. Highly aggressive workloads may still require
occassional garbage collection.
This abstracts away pointer packing tricks to a macro,
fixes comparison of pointers to occur in absence of
embedded values and improves robustness of pointer marshaling
for write-side operations for pointers that may already have
had pointer packing tricks played on them.
This function allows for faster insertions into tombstone-heavy
probe sequences by short-circuiting on tombstones rather than
continuing to probe. The user must already guarantee that the
entry being inserted is unique. If a non-unique key is inserted
with this operation, undefined behavior will result.
This assumes adjacent sector prefetch and appears to have minimal
clustering effect. In addition to this, developers are free to define
their own linear probe length by defining CK_HS_PROBE_L1_SHIFT.
Could not find suitable use-case and generally doesn't
appear interesting to academics in the existing
form. Maybe it will make a come-back in the future with
fewer memory and latency compromises.
This adds support for CAS_64{_VALUE}, CAS_PTR_2{_VALUE},
LOAD_64, STORE_64 and other primitives built on universal
CAS primitive.
Patch submitted by Olivier Houchard <cognet@FreeBSD>.
Samy Al Bahra
Samy Al Bahra
Artemiy Volkov