Timo Tijhof Krinkle

Profiling an application in Mac OS X

Finding which process to profile

If your system is running slowly, perhaps a process is using too much CPU time and won't let other processes run smoothly. To find out which processes are taking up a lot of CPU time, you can use Apple's Activity Monitor.

The CPU pane shows how processes are affecting CPU (processor) activity:

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

Beware of `<script async defer>` blocking HTML `"load"` event

2015.10.07 t

On the importance of simulated latency testing, and bulletproofing your page from the third-party JS load failures

TL;DR

The way of the `substack`

With over 200 modules in npm, and many such as browserify, dnode, optimist, etc. relied upon day-to-day by developers all around the world, substack is a pretty damn productive guy.

Plus, he's got an awesome philosophy on programming to boot (yes, there is a programming philosophy! ... no comprende? Let me explain later).

BTW, how do I know this? I got to talk to him at campjs as he wrote & published a module (lexical-scope to be exact). He was super friendly and shared alot of his thoughts on many topics.

All in all, it was really cool to meet someone that's completely congruent with what he says & lives out as a programmer. It almost felt Bret Victor-like.

Apps to install from macOS App Store:

Pastebot
GIF Brewery
Slack
Keynote/Pages/Numbers
1Password
OmniFocus 3
Airmail 3
iA Writer

Edit — February 2019

This gist had a far larger impact than I imagined it would, and apparently people are still finding it, so a quick update:

TC39 is currently moving forward with a slightly different version of TLA, referred to as 'variant B', in which a module with TLA doesn't block sibling execution. This vastly reduces the danger of parallelizable work happening in serial and thereby delaying startup, which was the concern that motivated me to write this gist
In the wild, we're seeing (async main(){...}()) as a substitute for TLA. This completely eliminates the blocking problem (yay!) but it's less powerful, and harder to statically analyse (boo). In other words the lack of TLA is causing real problems
Therefore, a version of TLA that solves the original issue is a valuable addition to the language, and I'm in full support of the current proposal, which you can read here.

I'll leave the rest of this document unedited, for archaeological

	## Pre-requisite: You have to know your last commit message from your deleted branch.
	git reflog
	# Search for message in the list
	# a901eda HEAD@{18}: commit: <last commit message>

	# Now you have two options, either checkout revision or HEAD
	git checkout a901eda
	# Or
	git checkout HEAD@{18}

	/**
	* https://tfl.gov.uk/corporate/terms-and-conditions/tfl-call-charges
	*
	* > The rate is 0.66p per minute.
	* > There is also a 40p connection charge.
	* > Call charges are rounded up to the nearest 10p, with a minimum charge of 60p.
	*
	* @param {number} seconds
	* @return {string} Cost in GBP
	*/

	#!/usr/bin/env python3
	# -- coding: utf8 --
	"""
	takeover.py
	~~~~~~~~~~~
	This script demonstrates a technique for zero-downtime restarts via
	interprocess descriptor transfer.

	The script operates a simple echo service on port 9999. When a new instance
	is launched, the old instance will transfer the server socket to the new

	var supportsES6 = function() {
	try {
	new Function("(a = 0) => a");
	return true;
	}
	catch (err) {
	return false;
	}
	}();