GLMeece

Latency Comparison Numbers

Note: "Forked" from Latency Numbers Every Programmer Should Know

Event	Nanoseconds	Microseconds	Milliseconds	Comparison
L1 cache reference	0.5	-	-	-
Branch mispredict	5.0	-	-	-
L2 cache reference	7.0	-	-	14x L1 cache
Mutex lock/unlock	25.0	-	-	-

Mohamed3on

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

Array

Definition:

• Stores data elements based on an sequential, most commonly 0 based, index.
• Based on tuples from set theory.

danisfermi

Here are the steps to installing and setting up GDB on Mac OS Sierra/High Sierra. Run brew install gdb. On starting gdb, you will get the following error:

Unable to find Mach task port for process-id 2133: (os/kern) failure (0x5).
 (please check gdb is codesigned - see taskgated(8))

To fix this error, follow the following steps:

laurencei

Steps to recreate tests:

// Create and configure server:
1. Create 2GB DigitalOcean server using Forge
2. Enable OpCache on server
3. Create http://domain1.com (use whatever domain name you have available)
4. Create http://domain2.com (use whatever domain name you have available)
5. Enable SSL on both domains using LetsEncrypt
6. Install: sudo apt-get install apache2-utils

thomasdarimont

version: '2'
services:
  openldap:
    image: osixia/openldap:1.2.3
    container_name: openldap
    environment:
      LDAP_LOG_LEVEL: "256"
      LDAP_ORGANISATION: "Example Inc."
      LDAP_DOMAIN: "example.org"
      LDAP_BASE_DN: ""

php-cpm

<?php
  $error = ['code'=>0,'msg'=>''];
  $req = json_decode(file_get_contents("php://input"), true);
  if (//https://developer.apple.com/documentation/appstoreservernotifications/responsebodyv1
    !isset($req['environment']) ||
    //https://developer.apple.com/documentation/appstoreservernotifications/responsebodyv2
    !isset($req['signedPayload']) {
    $error = ['code' => 400, 'msg' => 'params error'];
      return $error;
  }