Recent posts by Dr. Cliff Click

Dr. Cliff Click - April 4th, 2011
Function inlining in JVMs is a solved problem, right? It's a key performance optimization routinely done by JIT's everywhere (some might say: THE key optimization). Inlining has more than a decade of fine tuning in the Java context and over 40 years of production experience in the compilers and systems before that.
Dr. Cliff Click - March 19th, 2011
I'm off to another conference - this time TSSJS in Las Vegas.
Dr. Cliff Click - February 17th, 2011
Well, I’m baaaaack….. after a nearly year-long hiatus. I went to FOSDEM this year, in Brussels.
Dr. Cliff Click - July 24th, 2010


A Short and Sweet (and Deep) Brain Dump -

About Unsafe and CompareAndSwap (and NonBlockingHashMap).


A reader asked me: where is the volatile-like orderings guaranteed in NBHM?



  1. CAS - Compare-And-Swap instruction (or on IBM Power chips: Load-Linked / Store-Conditional).  The unit of Atomic Update on all modern CPUs, required for any sort of multi-cpu programming.
  2. Unsafe - Java-level access to raw memory.  In old-school spea
Dr. Cliff Click - July 16th, 2010

Gadzooks, time flies!  Been too long since I blogged...  no time for something deep so here's another quicky brain dump.

Azul Systems has been running HotSpot with a Tiered Compilation system since 2007 in our production sites, and I thought I'd blog a little about how that works.

Jargon terms first:

Dr. Cliff Click - June 9th, 2010

2010 ISMM & PLDI in Toronto, CA

Skip to the techy parts...


As mentioned in my last blog, I am flying into Toronto from Lisbon, Portugal.  There is no direct flight, so I'm taking US Airways and connecting through Philadelphia.  The flight over is fairly easy and in daylight the whole way so no chance I get any sleep - no problem, the quickest way for me to kick jet-lag is to stay up late anyways (not that I get over jet-lag very rapidly in any case).


We arrive on time,

Dr. Cliff Click - June 4th, 2010

I got an all-expense-paid vacation to Portugal, in exchange for giving a few talks and chatting with Joao Cachopo's group about STMs.  His group has the only commercially successful use of an STM that I know about - the Fenix system.  The  Instituto Superior Técnico (biggest engineering faculty of Portugal) runs on it, including all student courses, grading, teachers, scheduling, etc.

Dr. Cliff Click - May 1st, 2010

I had a set of long email exchanges with Doug Lea, reprinted here (with permission).  Lightly edited for clarity and the rare NDA-only material.  I resorted several of the interleaved conversations to make them flow better - but the original emails are highly interwoven.


Dr. Cliff Click - April 29th, 2010

Ok, I got a Real Blog cooking up but I want to see the new system work so people can comment.


The RSS feed should work.


Comments should work.


Please can I get a few comments from readers so I know the blog is functional?


When I see it working I'll can this blog post and put up some Real Stuff.






Dr. Cliff Click - April 21st, 2010

More news from the Internet connected-tube-thingy:


Cool -

From: cmck....

I'm going to reference the blog on the landing page tomorrow. I know the readership will be more than pleased that we successfully poked the bear and got some insight from Cliff.


Also - managed to raise the ire of Azul Systems' Cliff Click, Jr., ...