Jarrod Parker adkatrit

Distributed Read-Write Mutex in Go

The default Go implementation of sync.RWMutex does not scale well to multiple cores, as all readers contend on the same memory location when they all try to atomically increment it. This gist explores an n-way RWMutex, also known as a "big reader" lock, which gives each CPU core its own RWMutex. Readers take only a read lock local to their core, whereas writers must take all locks in order.

	# requires jq, curl

	# genie_job_status <HOST> <JOB_ID>
	genie_job_status(){
	GENIE_HOST=$1;
	GENIE_JOB_ID=$2;
	curl --silent "$GENIE_HOST/api/v3/jobs?size=100" \| jq -rc '._embedded.jobSearchResultList[] \| [.id,.status]' \| grep $GENIE_JOB_ID;
	}

	# job_heartbeat <HOST> <JOB_ID> <BEEP INTERVAL IN SECONDS>

	package main
	import (
	"fmt"
	"sync"
	"github.com/satori/go.uuid"
	)

	type PGM struct{
	Vertices map[uuid.UUID]*Vertex
	Edges map[uuid.UUID]*Edge

	#!/bin/bash

	INDEX="corp-reg"
	ES_SOCKET="10.0.1.109:9200"

	#Create index
	curl -XPUT "$ES_SOCKET/$INDEX/"

	#replicas
	curl -XPUT "$ES_SOCKET/$INDEX/_settings" -d '{

	/* sigmajs.org - an open-source light-weight JavaScript graph drawing library - Version: 0.1 - Author: Alexis Jacomy - License: MIT */
	var sigma={tools:{},classes:{},instances:{}};
	(function(){if(!Array.prototype.some)Array.prototype.some=function(i,n){var g=this.length;if("function"!=typeof i)throw new TypeError;for(var j=0;j<g;j++)if(j in this&&i.call(n,this[j],j,this))return!0;return!1};if(!Array.prototype.forEach)Array.prototype.forEach=function(i,n){var g=this.length;if("function"!=typeof i)throw new TypeError;for(var j=0;j<g;j++)j in this&&i.call(n,this[j],j,this)};if(!Array.prototype.map)Array.prototype.map=function(i,n){var g=this.length;if("function"!=typeof i)throw new TypeError;
	for(var j=Array(g),m=0;m<g;m++)m in this&&(j[m]=i.call(n,this[m],m,this));return j};if(!Array.prototype.filter)Array.prototype.filter=function(i,n){var g=this.length;if("function"!=typeof i)throw new TypeError;for(var j=[],m=0;m<g;m++)if(m in this){var t=this[m];i.call(n,t,m,this)&&j.push(t)}return j};if(!Object.keys)Objec

	#Usage: netz google.com
	function netz(){
	while :; do ping -W1 -c1 -n $1 > /dev/null && say "internet alert"; sleep 1; done
	}