Vaughn GH VaughnGH

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

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	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
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	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,

	https://www.pdf-archive.com/2011/01/01/great-big-hug-cowl-pattern-version-1/great-big-hug-cowl-pattern-version-1.pdf
	https://www.pdf-archive.com/2011/01/01/brentsteinbergillustrations/brentsteinbergillustrations.pdf
	https://www.pdf-archive.com/2011/01/01/summing-up-transfers-on-january-1st/summing-up-transfers-on-january-1st.pdf
	https://www.pdf-archive.com/2011/01/03/10-retro/10-retro.pdf
	https://www.pdf-archive.com/2011/01/03/10-vol/10-vol.pdf
	https://www.pdf-archive.com/2011/01/03/progress-report-28-12-2010/progress-report-28-12-2010.pdf
	https://www.pdf-archive.com/2011/01/03/guide/guide.pdf
	https://www.pdf-archive.com/2011/01/03/dating-relationships-and-all-that-awkward-stuff/dating-relationships-and-all-that-awkward-stuff.pdf
	https://www.pdf-archive.com/2011/01/04/q1-and-q2/q1-and-q2.pdf

	<!DOCTYPE html>
	<html>
	<head><title>Fizzlefade</title></head>

	<body>

	<canvas id="framebuffer" width="320" height="200"></canvas>

	<script type="text/javascript">
	/* Fizzlefade using a Feistel network.

	#!/bin/bash

	# Validate the input
	if [ "$#" -ne 1 ]; then
	printf "Enter a branch number only\n"
	exit
	fi

	# Special case if the argument is "-"
	if [ $1 = "-" ];

	first, create a bash script, put this in it.

	#!/bin/bash
	while IFS='' read -r line \|\| [[ -n "$line" ]]; do
	curl --user-agent "$line" <the url you want to troll>
	done < "$1"

	Name it something dumb. logshove.sh

	Next create a file with no url-encodable chars. Make sure every line is the same length. don't use spaces. I used periods.

	###############################################################################
	# Batch script for setting up fun Python libraries for Computational Methods in the Civic Sphere 2017
	#
	# Should be run after installing Anaconda 4.2+/Python 3.5+ via https://www.continuum.io/downloads
	#
	# Doesn't include libraries that are installed as dependencies (e.g. numpy via pandas)
	##############################################################################

	##############################################################################
	###### Yes

	Create a tmux conf file
	#> touch ~/.tmux.conf

	Install TMP
	#> git clone https://github.com/tmux-plugins/tpm ~/.tmux/plugins/tpm

	[Copy and paste tmux.conf below into local file.]

	Load tmux configurations
	#> tmux source-file ~/.tmux.conf

	Edit the gmetad.conf file of Ganglia to include the following values:

	carbon_server: "localhost"
	carbon_port: 3000
	carbon_protocol udp
	carbon_timeout 500


	Edit the influxdb.conf file of InfuxDB to include the following values:

	# The trick is to link the DeviceSupport folder from the beta to the stable version.
	# sudo needed if you run the Mac App Store version. Always download the dmg instead... you'll thank me later :)

	# Support iOS 15 devices (Xcode 13.0) with Xcode 12.5:
	sudo ln -s /Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/15.0 /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport

	# Then restart Xcode and reconnect your devices. You will need to do that for every beta of future iOS versions

	# (A similar approach works for older versions too, just change the version number after DeviceSupport)