Monday, March 31, 2014

Firefox: Generational GC has landed (blog.mozilla.org)

Big news: late last week, generational garbage collection landed. It was backed out at first due to some test failures, but then re-landed and appears to have stuck. This helps with performance. There are certain workloads where generational GC makes the code run much faster, and Firefox hasn’t been able to keep up with Chrome on these. For example, it has made Firefox slightly faster on the Octane benchmark, and there is apparently quite a bit of headroom for additional improvements. Read more...

Thursday, March 20, 2014

Green threads are just threads (glyph.twistedmatrix.com)

Be as the reed, not the oak tree. Green threads are just threads.

    … that which is hard and stiff
    is the follower of death
    that which is soft and yielding
    is the follower of life …

    – the Tao Te Ching, chapter 76

As we know, threads are a bad idea, (for most purposes). Threads make local reasoning difficult, and local reasoning is perhaps the most important thing in software development. With the word “threads”, I am referring to shared-state multithreading, despite the fact that there are languages, like Erlang and Haskell which refer to concurrent processes – those which do not implicitly share state, and require explicit coordination – as “threads”. My experience is mainly (although not exclusively) with Python but the ideas presented here should generalize to most languages which have global shared mutable state by default, which is to say, quite a lot of them: C (including Original Recipe, Sharp, Extra Crispy, Objective, and Plus Plus), JavaScript, Java, Scheme, Ruby, and PHP, just to name a few. With the phrase “local reasoning”, I’m referring to the ability to understand the behavior (and thereby, the correctness) of a routine by examining the routine itself rather than examining the entire system. Read more

Wednesday, March 5, 2014

Critical crypto bug leaves Linux, hundreds of apps open to eavesdropping (arstechnica.com)

Hundreds of open source packages, including the Red Hat, Ubuntu, and Debian distributions of Linux, are susceptible to attacks that circumvent the most widely used technology to prevent eavesdropping on the Internet, thanks to an extremely critical vulnerability in a widely used cryptographic code library. The bug in the GnuTLS library makes it trivial for attackers to bypass secure sockets layer (SSL) and Transport Layer Security (TLS) protections available on websites that depend on the open source package. Initial estimates included in Internet discussions such as this one indicate that more than 200 different operating systems or applications rely on GnuTLS to implement crucial SSL and TLS operations, but it wouldn't be surprising if the actual number is much higher. Web applications, e-mail programs, and other code that use the library are vulnerable to exploits that allow attackers monitoring connections to silently decode encrypted traffic passing between end users and servers. Read more...