The recent issues with Google’s WEI proposal have provided for a few more views of this blog and website, which makes it worth diving into our work a little again. The previous post on resource access is quite old at this stage, after all. Quick Recap Under different grants, we’ve been working on a bunch of loosely related technologies. The highlights are: Channeler – a protocol that has can switch between UDP-like lossy and TCP-like lossless modes of connection, as well as novel modes suitable for live broadcast.

Previously, I wrote about how to use Valgrind for debugging memory issues – and today, I’d like to go into how to use the tool for profiling. As I wrote before, Valgrind is an instrumentation framework that provides a collection of tools. For profiling, we’ll look at the Callgrind tool together a GUI application called KCachegrind. As a quick historical note, the predecessor to Callgrind is called Cachegrind, and was mostly for examining CPU cache usage – but Callgrind was developed out of that.

A recent thread on social media reminded me that some of the development tools I take for granted are not widely known. Veteran game developer Martin Linklater (@Fizzychicken@mastodon.gamedev.place) asked about profiling on Linux, which prompted me to mention my favourite Valgrind, which prompted a question about its use. I offered to write up a quick tutorial on it. But thinking about it a little more, quick, introductory tutorials to the tools we use makes for a useful addition to this section of the blog.

Previously, I’ve been writing about how to perform task delegation with a distributed authorization scheme. While that article managed to outline the principle well enough, it left a few things not yet covered. The summary was that if we find a generic scheme for treating a resource as a series of changes, then we can encrypt and authenticate each change separately, leading to a kind of distributed authorship of resources – which is what we really want in a distributed system.