Memory barriers, or fences, are a set of processor instructions used to apply ordering limitations on memory operations. This article explains the impact memory barriers have on the determinism of multi-threaded programs. We'll look at how memory barriers relate to JVM concurrency constructs such as volatile, synchronized and atomic conditionals.
This article describes "the hardest topic in OSGi, how to deal with service dynamics," based on personal experience. Two factors, concurrency and direct service references, make the problem "fiendishly hard." An import and an export policy should form a comprehensive doctrine for dealing with service dynamics and the article explores two export policies with their corresponding doctrines.
Cloud services have helped bring virtualization to the forefront. Its full power however, also includes other benefits such as high availability, disaster recovery, and rapid provisioning. 1
Ruby 1.9's Fibers and non-blocking I/O are getting more attention - we talked to Mohammad A. Ali of the NeverBlock project and Tony Arcieri of the Revactor project. 1
One of the most exciting things in Java right now is the work being done to get other programming languages onto the JVM. If you want to try something very different from Java, Lisp is a great option. 12
Jeroen Borgers examines if biased locking, lock coarsening, lock elision by escape analysis and adaptive spin locking techniques in the latest JVMs actually work in highly-concurrent apps. 3
Jeroen Borgers examines if biased locking, lock coarsening, lock elision by escape analysis and adaptive spin locking techniques in the latest JVMs actually work in highly-concurrent apps. 16
"Ruby has no debugger" - this misconception has stuck around for ages. Time to eradicate it: Ruby does indeed have powerful debugging support. We look at what's available for all Ruby implementations.
Simon Ritter explains the vision and capabilities of the Real-Time Java specification (RTSJ), which will bring guaranteed response times regardless of GC. 3
Finding performance bottlenecks can be a difficult task and it can get more difficult as our applications grow in size. The Box is a methodology tool that focuses us efforts to improve performance. 6
Orion Letizi goes in-depth on OpenTerracotta, an open-source JVM-level clustering solution that can cluster single-jvm apps with no code changes. 10