Release 0.5.1

[Samy Al Bahra]

Concurrency Kit 0.5.1 has been released. This release includes critical bug
fixes to ck_epoch. It is recommended all users of ck_epoch upgrade.
ck_epoch_{synchronize,barrier} now provides full barrier semantics.
ck_epoch_poll provides acquire semantics. A bug fix in ck_epoch_section_t
support is also included.

The ck_epoch_section_t issue only affects users who are taking advantage of
nested epoch sections (non-NULL ck_epoch_section_t argument). Such sections
that never leave the outermost protected section will cause write-side
operations to hang due to an invalid mask being applied to bucket selection. An
additional regression test has been added for epoch sections that better
stresses forward-progress guarantees of the ck_epoch_section_t extensions.

ck_pr_fence_memory has also been changed to emit fences on TSO. This is not the
idiom provided by various kernel facilities, but it is more consistent to
provide this behavior since Concurrency Kit provides a richer fencing
interface. Generally, it is expected a full fence is used in cases where
weaker fences (of X_Y / acq-rel form) are insufficient and so, a fence should
be emitted.

Download:
http://concurrencykit.org/releases/ck-0.5.1.tar.gz
http://concurrencykit.org/releases/ck-0.5.1.zip
http://concurrencykit.org/releases/ck-0.5.1.spec