Posts that commenters keep linking to, ranked by how many different people have cited them in Hacker News comments. 71 posts.
See how well you know (or can anticipate) gcc's optimizer. For each question, the left box contains some code, while the right box contains code that purports to do the same thing, but that illustrates a particular optimization. Will gcc apply that optimization? Put another way, will the code on the left be as fast as…
All the recent media attention on Bitcoin inspired me to learn how Bitcoin really works, right down to the bytes flowing through the netwo...
TL:DR Successive, well intentioned, changes to architecture and technology throughout the lifetime of an application can lead to a fragmente...
In P of EAA I said "don't distribute your objects". Does this advice contradict my interest in Microservices?
It's time for servers to handle 10 million simultaneous connections, don't you think? After all, computers now have 1000 times the memory as...
Recently the topic of systemd has come up quite a bit in various communities in which I'm involved, including the musl IRC channel and on the Busybox mailing list .
Update: Together with Udacity I created a free offline-first interactive course . It involves taking an online-only site to full offline-first glory. Many of the patterns in this article are used.
Are you interested in learning more about working on Asana's engineering team or the work they do? Read the Asana engineering blog.
Now, we don't want to truly change the observable behaviour of our software — but fortunately the C standard has a more liberal concept of "observable" than most people. In particular, the C standard states that the observable behaviour includes accesses to volatile objects . What is a volatile object, you ask? It is…
How-to articles about designing safe, reliable, and secure embedded systems.
Posted by Chris Evans, Exploit Writer Underling to Tavis OrmandyBack in this 1998 post to the Bug...
RabbitMQ is a distributed message queue, and is probably the most popular open-source implementation of the AMQP messaging protocol. It supports a wealth of durability, routing, and fanout strategies, and combines excellent documentation with well-designed protocol extensions. I’d like to set all these wonderful…
When you have to traverse some sort of a nested data structure (say, a binary tree), one approach is to create a stack that remembers where in the tree you are. Another, much more elegant approach, is to write the function recursively. A recursive function employs the machine stack used to implicitly implement…
I’m a huge fan of interactive programming (see: JavaScript , Java , Lisp , Clojure ). That is, modifying and extending a program while it’s running. For certain kinds of non-batch applications, it takes much of the tedium out of testing and tweaking during development. Until last week I didn’t know how to apply…
Every once in a while I run into an obscure computer technology that is a hidden gem, which over the years has become mostly forgotten. This is exactly how I feel about the tcpdump tool and its kernel counterpart the packet filter interface.
A few hours ago, I sent the following “dear colleagues” email (lightly edited to remove some private details) to all my users at work: This has been a very trying week. For those of you…
Apache Storm recently became a top-level project , marking a huge milestone for the project and fo...
My previous entry has the amazingly interesting title "Blogging is hard". Gee, what a wuss, says the occasional passer-by. Gotta fix my image, fast. Think, think, think! OK, here's what I'm going to tell you: low-level programming is easy. Compared to higher-level programming, that is. I'm serious.
Here's the graph of a toy benchmark 1 of page-aligned vs. mis-aligned accesses; it shows a ratio of performance between the two at different working set sizes. If this benchmark seems contrived, it actually comes from a real world example of the disastrous performance implications of using nice power of 2 alignment…
With the recent announcement of a commercial game shipping using Emscripten and asm.js , I thought it’d be a good time to explain how asm.js is executed in Firefox and some of the load-time optimizations we’ve made since the initial landing of OdinMonkey in March. (OdinMonkey is an optimization module inside Mozilla’s…
So many weird little demands on time, mostly spinning out of the Signal groups set up to counter ICE and now being used for general community stuff.
About three years ago I wrote an article analyzing the memory usage of arrays in PHP 5. As part of the work on the upcoming PHP 7, large parts of the Zend Engine have been rewritten with a focus on smaller data structures requiring fewer allocations. In this article I will provide an overview of the new hashtable…
When writing networked games, the question of UDP vs TCP will eventually come up. Typically you will hear people say things like: “Unless you’re doing action games, you can use TCP̶…
