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@staltz
staltz / introrx.md
Last active May 2, 2024 12:31
The introduction to Reactive Programming you've been missing
@jboner
jboner / latency.txt
Last active May 2, 2024 09:45
Latency Numbers Every Programmer Should Know
Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD
@fabiofl
fabiofl / gist:5873100
Created June 27, 2013 00:41
Clear Mac OS X's icon cache.
sudo find /private/var/folders/ -name com.apple.dock.iconcache -exec rm {} \;

Quick Tips for Fast Code on the JVM

I was talking to a coworker recently about general techniques that almost always form the core of any effort to write very fast, down-to-the-metal hot path code on the JVM, and they pointed out that there really isn't a particularly good place to go for this information. It occurred to me that, really, I had more or less picked up all of it by word of mouth and experience, and there just aren't any good reference sources on the topic. So… here's my word of mouth.

This is by no means a comprehensive gist. It's also important to understand that the techniques that I outline in here are not 100% absolute either. Performance on the JVM is an incredibly complicated subject, and while there are rules that almost always hold true, the "almost" remains very salient. Also, for many or even most applications, there will be other techniques that I'm not mentioning which will have a greater impact. JMH, Java Flight Recorder, and a good profiler are your very best friend! Mea

Thread Pools

Thread pools on the JVM should usually be divided into the following three categories:

  1. CPU-bound
  2. Blocking IO
  3. Non-blocking IO polling

Each of these categories has a different optimal configuration and usage pattern.

@bishboria
bishboria / springer-free-maths-books.md
Last active April 25, 2024 06:27
Springer made a bunch of books available for free, these were the direct links
@MattPD
MattPD / analysis.draft.md
Last active April 24, 2024 14:53
Program Analysis Resources (WIP draft)
@edolstra
edolstra / nix-lang.md
Last active April 19, 2024 04:04
Nix language changes

This document contains some ideas for additions to the Nix language.

Motivation

The Nix package manager, Nixpkgs and NixOS currently have several problems:

  • Poor discoverability of package options. Package functions have function arguments like enableFoo, but there is no way for the Nix UI to discover them, let alone to provide programmatic ways to
@0XDE57
0XDE57 / config.md
Last active April 18, 2024 04:36
Firefox about:config privacy settings

ABOUT

about:config settings to harden the Firefox browser. Privacy and performance enhancements.
To change these settings type 'about:config' in the url bar. Then search the setting you would like to change and modify the value. Some settings may break certain websites from functioning and rendering normally. Some settings may also make firefox unstable. I am not liable for any damages/loss of data.

Not all these changes are necessary and will be dependent upon your usage and hardware. Do some research on settings if you don't understand what they do. These settings are best combined with your standard privacy extensions (HTTPS Everywhere No longer required: Enable HTTPS-Only Mode, NoScript/Request Policy, uBlock origin, agent spoofing, Privacy Badger etc), and all plugins set to "Ask To Activate".

@burke
burke / 0-readme.md
Created January 27, 2012 13:44 — forked from funny-falcon/cumulative_performance.patch
ruby-1.9.3-p327 cumulative performance patch for rbenv

ruby-1.9.3-p327 cumulative performance patch for rbenv

This installs a patched ruby 1.9.3-p327 with various performance improvements and a backported COW-friendly GC, all courtesy of funny-falcon.

Requirements

You will also need a C Compiler. If you're on Linux, you probably already have one or know how to install one. On OS X, you should install XCode, and brew install autoconf using homebrew.