David Smith codeactual

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.
Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

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	#!/bin/bash
	set -e
	set -o pipefail

	# Add user to k8s using service account, no RBAC (must create RBAC after this script)
	if [[ -z "$1" ]] \|\| [[ -z "$2" ]]; then
	echo "usage: $0 <service_account_name> <namespace>"
	exit 1
	fi

	#!/usr/bin/python3
	#
	# usage: python3 docker_descendants.py <image_id> ...

	import sys
	from subprocess import check_output


	def main(images):
	image_ids = set(images)

	public enum Direction {
	case forward
	case backward
	}

	internal var player: AVPlayer?

	private var isSeekInProgress = false
	private var chaseTime = kCMTimeZero
	private var preferredFrameRate: Float = 23.98

	package main

	import (
	"database/sql"
	"fmt"
	"net/url"
	"os"
	"reflect"
	"regexp"
	"strconv"

	//
	// UIScrollViewWrapper.swift
	// lingq-5
	//
	// Created by Timothy Costa on 2019/07/05.
	// Copyright © 2019 timothycosta.com. All rights reserved.
	//

	import SwiftUI

	struct ContentView: View {
	@State var moved: CGFloat = 0
	@State var startTime: Date?
	var body: some View {

	//0 means that it acts like a press
	//coordinateSpace local means local to the view its added to
	let tap = DragGesture(minimumDistance: 0, coordinateSpace: .local)
	.onChanged { value in
	//store distance the touch has moved as a sum of all movements

	function switchgo() {
	version=$1
	if [ -z $version ]; then
	echo "Usage: switchgo [version]"
	return
	fi

	if ! command -v "go$version" > /dev/null 2>&1; then
	echo "version does not exist, download with: "
	echo " go get golang.org/dl/go${version}"

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