RFR: 8189088: Add intrusive doubly-linked list utility

Kim Barrett kim.barrett at oracle.com
Tue Oct 10 08:29:57 UTC 2017

RFR: 8189088: Add intrusive doubly-linked list utility

Please review this new facility, providing a general mechanism for
intrusive doubly-linked lists. A class supports inclusion in a list by
having an IntrusiveListLink member, and providing structured
information about how to access that member. A class supports
inclusion in multiple lists by having multiple IntrusiveListLink
members, with different lists specified to use different members.

The IntrusiveList class template provides the list management. It is
modelled on bidirectional containers such as std::list and
boost::intrusive::list, providing many of the expected member types
and functions. (Note that the member types use the Standard's naming
conventions.) (Not all standard container requirements are met; some
operations are not presently supported because they haven't been
needed yet.) This includes iteration support using (mostly)
standard-conforming iterator types (they are presently missing
iterator_category member types, pending being able to include
<iterator> so we can use std::bidirectional_iterator_tag).

This change only provides the new facility, and doesn't include any
uses of it, though there is a suite of unit tests for it. I've
extracted it from some in-progress work, as a useful tool in it's own

I've converted a couple existing list implementations to use
IntrusiveList, and will be submitting those changes once this
infrastructure is in place. One place I haven't yet touched that I
think will benefit is G1's region handling. There are various places
where G1 iterates over all regions in order to do something with those
which satisfy some property (humongous regions, regions in the
collection set, &etc). If it were trivial to create new region
sublists (and this facility makes that easy), some of these could be
turned into direct iteration over only the regions of interest.



JPRT to build and run unit tests on supported platforms.

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