seboudry

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns                     on recent CPU
L2 cache reference ........................... 7 ns                     14x L1 cache
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns                     20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs 4X memory

egonSchiele

require 'thread'

class Waiter
  def initialize
    @mutex = Mutex.new
  end

  def can_eat? philosopher
    left = philosopher.left_fork
    right = philosopher.right_fork

egonSchiele

require 'rubygems'
require 'celluloid'

class Waiter
  include Celluloid
  FORK_FREE = 0
  FORK_USED = 1
  attr_reader :philosophers
  attr_reader :forks
  attr_reader :eating

egonSchiele

require 'thread'
 
class Ron
  def initialize(name, left_fork, right_fork)
    @name = name
    @left_fork = left_fork
    @right_fork = right_fork
    while true
      think
      dine

gbigwood

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;

/**
 * To run:

nvanderw

public class Thunks {
    /**
     * Interface which represents unary functions. Can be anonymously
     * instantiated to simulate lambdas.
     */
    public static interface Fn<A, B> {
        public B call(A arg);
    }

    /**

maccman

class Point
  constructor: (@x = 0, @y = 0) ->
    if isNaN(@x) or isNaN(@y)
      throw new Error('Invalid coords')

  add: (point) ->
    @x += point.x
    @y += point.y

  subtract: (point) ->

stober

#!/usr/bin/python
"""
Author: Jeremy M. Stober
Program: GP.PY
Date: Thursday, July 17 2008
Description: Example of Gaussian Process Regression.
"""

from numpy import *
import pylab

vmihailenco

package main

import (
	"bytes"
	"encoding/hex"
	"flag"
	"fmt"
	"io"
	"log"
	"net"

utaal

webserver: webserver.c libuv/uv.a http-parser/http_parser.o
	gcc -I libuv/include \
    -lrt -lm -lpthread -o \
    webserver webserver.c \
    libuv/uv.a http-parser/http_parser.o

libuv/uv.a:
	$(MAKE) -C libuv

http-parser/http_parser.o: