keeping simple

Category: systems

  • Are threads evil? (updated)

    This paper by Prof. Edward Lee explains something of why “threads” are such a painful abstraction.  As Prof. Lee notes, threads intrinsically create unspecified program operation (which he calls non-determinism) and resource conflicts which we then attempt to “prune” via synchronization and complex tools. In an earlier note, I argued that we should design real-time…

  • Mobile device security and President Obama

    Obama’s fighting hard to keep his Blackberry President Barack Obama will have a beloved BlackBerry — and maybe a second, more secure smartphone-like device — with him in the White House. The president has been adamant about continuing to use a BlackBerry, a smartphone with Internet and e-mail access, despite concerns that are likely making…

  • Fault tolerant patent application for virtual machine

    [0018]For incoming network packets, the following is done during the logging mode. When a packet is received, an event-request is posted for the VMM, at Block 210. When the VMM processes the event, it stops the VM, synchronizes the guest VCPU state, and then calls into the device emulator (i.e., device emulation software event handler),…

  • fault tolerant patent

    So I don’t understand the novelty in the methods here over the Glazer patent. The replica supervisors provide interfaces to the replicas that are the same as the interface provided by the operating system. Thus, when one of the replicas makes a call to the operating system, the corresponding replica supervisor is invoked and the…

  • Apple’s spotlight and future databases

    The UNIX idea that the OS treated files as sequences of uninterpreted bytes was a brilliant technical simplification – so successful that the previously dominant approach essentially disappeared. Apple seems to want to revist the issue with its spotlight product.  Maybe it is time time integrate a database view into the file system, now that…

  • Updated Dijkstra vs Perlis (really, DeMillo)

    See below.

  • Dijkstra versus Perlis (updated)

    Dijkstra wrote: He [Perlis] published a very obnoxious paper arguing against a mathematical approach to programming cite The paper  by De Millo, Lipton and Perlis  starts as follows: Many people have argued that computer programming should strive to become more like mathematics. Maybe so, but not in the way they seem to think. The aim of program…

  • future of the data center

    This article from Ars Technica discusses a talk over the summer by Merrill Lynch’s chief technology architect, Jeffrey Birnbaum on “stateless cloud computing” – most concretely on distributed file systems. Birnbaum believes that one of the key foundational elements of a stateless computing environment is a networked storage system that enables ubiquitous availability of software.…

  • Operating system research – 16 years perspective

    (links and dates fixed March 15 2015 – thanks to Luu and pm90 at news.y.combinator for digging this up) October 2008: It’s somewhat funny and somewhat sad to read this thread on the old USENET. Starting out with Andy Tanenbaum’s proposed list of accepted truths (most of which I thought wrong at the time) GENERALLY ACCEPTED AS…

  • New paper “H2” on operating system semantics

    Please see a new version here. I am continuing to try to develop a practical engineering mathematics for operating system and other complex system code.