Showing posts with label contention. Show all posts
Showing posts with label contention. Show all posts

Monday, July 18, 2016

Angelika Langer at GOTO 2014

If you want a soft intro to some of the concurrency features introduced in Java 8, here is a video by Angelika Langer at GOTO 2014


I don't know much about the Future's stuff, but the part about StampedLock and Contended is well explained, with intuitive examples as well.
In fact, she makes it look so easy to use StampedLock and particularly the optimistic API of tryOptimiscRead()/validate() that someone who is new to it may think it is easy... it's not.

IMO using optimistic concurrency is like juggling knifes, and I've ranted about it before and will rant about it again on my next post, but I am happy that people are talking about and explaining it in such detail... too bad they didn't give her enough time to explain all the issues that can occur with tryOptimiscRead()/validate(), but in these conferences time is always short so you never get to present everything you want.


Tuesday, December 31, 2013

Martin Thompson on Lock-Free algorithms


Recorded at QCon last year, this presentation by Martin Thompson starts with an intro to caches on modern microprocessors, then talks about Consistency models, the x86 memory model, and then talks about languages Memory Model (Java, C++11, Erlang).
The presentation then passes over to Michael Barker which talks about Model Specific Registers.
Martin then talks about Contention and Amdahl's Law, locks, atomic instructions. He then goes into what he calls "lock-free algorithms", but he only covers Queues. He does a comparison study of performance an latency for the ConcurrentLinkedQueue, ArrayBlockingQueue, LinkedBlockingQueue, and others.
Michael then takes back control, and talks about False Sharing and some performance benchmarks they did with and without padding.

http://www.infoq.com/presentations/Lock-free-Algorithms



If you don't know who Martin Thompson is, then check out his blog:
http://mechanical-sympathy.blogspot.co.uk/
and Michael Barker's http://bad-concurrency.blogspot.co.uk/