Sebastian Zuchmanski zuchmanski

The introduction to Reactive Programming you've been missing

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

My largest Sidekiq application had a memory leak and I was able to find and fix it in just few hours spent on analyzing Ruby's heap. In this post I'll show my profiling setup.

As you might know Ruby 2.1 introduced a few great changes to ObjectSpace, so now it's much easier to find a line of code that is allocating too many objects. Here is great post explaining how it's working.

I was too lazy to set up some seeding and run it locally, so I checked that test suite passes when profiling is enabled and pushed debugging to production. Production environment also suited me better since my jobs data can't be fully random generated.

So, in order to profile your worker, add this to your Sidekiq configuration:

if ENV["PROFILE"]

High-Performance Matrix Multiplication

This is a short post that explains how to write a high-performance matrix multiplication program on modern processors. In this tutorial I will use a single core of the Skylake-client CPU with AVX2, but the principles in this post also apply to other processors with different instruction sets (such as AVX512).

Intro

Matrix multiplication is a mathematical operation that defines the product of

	#!/usr/bin/env jruby
	#
	#

	require 'rubygems'
	require 'spoon'

	EXEC = '/tmp/exec.rb'
	PID_PATH = '/tmp/exec.pid'
	WORK_PATH = '/tmp/'

	// Add this to user_extensions.js

	function withJQueryTriggers(proto, name) {
	var original = proto[name];
	proto[name] = function(locator, value) {
	original.call(this, locator, value);

	if (locator.indexOf("css=") == 0) {
	var selector = locator.replace("css=", "");
	LOG.info("triggering " + selector);

	import sys
	import ctypes
	pyint_p = ctypes.POINTER(ctypes.c_byte*sys.getsizeof(5))
	five = ctypes.cast(id(5), pyint_p)
	print(2 + 2 == 5) # False
	five.contents[five.contents[:].index(5)] = 4
	print(2 + 2 == 5) # True (must be sufficiently large values of 2 there...)

	#!/bin/sh
	set -e
	# Example init script, this can be used with nginx, too,
	# since nginx and unicorn accept the same signals

	# Feel free to change any of the following variables for your app:
	TIMEOUT=${TIMEOUT-60}
	APP_ROOT=/path/to/your/app/current
	PID=$APP_ROOT/tmp/pids/unicorn.pid
	ENVIRONMENT=production

	#!/usr/bin/env sh

	##
	# This is script with usefull tips taken from:
	# https://github.com/mathiasbynens/dotfiles/blob/master/.osx
	#
	# install it:
	# curl -sL https://raw.github.com/gist/2108403/hack.sh \| sh
	#

	$ rake test
	/opt/rubies/2.0.0-p0/bin/ruby -I"lib:test" -w -I"/Users/steve/.gem/ruby/2.0.0/gems/rake-10.0.4/lib" "/Users/steve/.gem/ruby/2.0.0/gems/rake-10.0.4/lib/rake/rake_test_loader.rb" "test/map_stream_test.rb" "test/map_test.rb" "test/merge_test.rb" "test/mvp_test.rb" "test/on_value_test.rb" "test/select_test.rb"
	/Users/steve/.gem/ruby/2.0.0/gems/simplecov-html-0.7.1/lib/simplecov-html.rb:57: warning: assigned but unused variable - title_id
	/Users/steve/.gem/ruby/2.0.0/gems/coveralls-0.6.7/lib/coveralls.rb:66: warning: `&' interpreted as argument prefix
	/Users/steve/.gem/ruby/2.0.0/gems/coveralls-0.6.7/lib/coveralls.rb:72: warning: `&' interpreted as argument prefix
	/Users/steve/.gem/ruby/2.0.0/gems/rest-client-1.6.7/lib/restclient/exceptions.rb:157: warning: assigned but unused variable - message
	/Users/steve/.gem/ruby/2.0.0/gems/rest-client-1.6.7/lib/restclient/exceptions.rb:167: warning: assigned but unused variable - message
	/Users/steve/.gem/ruby/2.0.0/gems/rest-client-1.6.7/lib/restclient/response.