chrisa23

On the topic of data locality and performance

Full source code can be found here

It is well-known that a hard disk has a long delay from that we request the data to that we get the data. Usually we measure the hard disk latency in milliseconds which is an eternity for a CPU. The bandwidth of a hard disk is decent good as SSD:s today can reach 1 GiB/second.

What is less known is that RAM has the same characteristics, bad latency with good bandwidth.

You can measure RAM latency and badndwidth using Intel® Memory Latency Checker. On my machine the RAM latency under semi-high load is ~120 ns (The 3r:1w bandwidth is 16GiB/second). This means that the CPU on my machine has to wait for ~400 cycles for data, an eternity.

chrisa23

[<AutoOpen>]
module StateMachine =

  type State =
    | StateA
    | StateB
    | StateC
    | StateD
    | End

chrisa23

//==========================================
// Working fully self-contained getting-started example for Suave Web Server scripting 
//
// Note you don't need to have _anything_ installed before starting with this script. Nothing
// but F# Interactive and this script.
//
// This script fetches the Paket.exe component which is referenced later in the script. 
// Initially the #r "paket.exe" reference is shown as unresolved. Once it has been
// downloaded by the user (by executing the first part of the script) the reference 
// shows as resolved and can be used.

chrisa23

//==========================================
// Working fully self-contained getting-started example for Suave Web Server scripting 
//
// Note you don't need to have _anything_ installed before starting with this script. Nothing
// but F# Interactive and this script.
//
// This script fetches the Paket.exe component which is referenced later in the script. 
// Initially the #r "paket.exe" reference is shown as unresolved. Once it has been
// downloaded by the user (by executing the first part of the script) the reference 
// shows as resolved and can be used.

chrisa23

/// <summary>
/// Wrapper for GDI text rendering functions<br/>
/// This class is not thread-safe as GDI function should be called from the UI thread.
/// </summary>
/// <remarks>
/// http://theartofdev.com/2013/08/12/using-native-gdi-for-text-rendering-in-c/<br/>
/// The MIT License (MIT) Copyright (c) 2014 Arthur Teplitzki.
/// </remarks>
public sealed class NativeTextRenderer : IDisposable
{

chrisa23

open System

/// A fake logger type.
type Logger =
    private { __ : unit }
    
[<RequireQualifiedAccess; CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
module Logger =
    let info (_ : string) (_ : Logger) = ()
    let warn (_ : string) (_ : Logger) = ()

chrisa23

/// A tic-tac-toe piece, or the absence thereof.
type Piece = U | X | O

/// Tic-tac-toe board position.
type Position = { X : int; Y : int }

/// A tic-tac-toe game implemented as a Pure ADT.
type Game =
    private
        { FirstPlayerTurn : bool

chrisa23

open FSharpx.State

/// A tic-tac-toe piece, or the absence thereof.
type Piece = U | X | O

/// Tic-tac-toe board position.
type Position = { X : int; Y : int }

/// A tic-tac-toe game implemented as a Pure ADT.
type Game =

chrisa23

open System
open FSharpx.Reader

/// A fake logger type.
type Logger =
    private { __ : unit }
    
[<RequireQualifiedAccess; CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
module Logger =
    let info (_ : string) (_ : Logger) = ()

chrisa23

/// A tic-tac-toe piece, or the absence thereof.
type Piece = U | X | O

/// Tic-tac-toe board position.
type Position = { X : int; Y : int }

/// A tic-tac-toe game implemented as a Pure ADT.
type Game =
    private
        { FirstPlayerTurn : bool