Part II: プロセスとスレッド

概要

本章では、スレッドの基本操作と Async を使った並列パスワードクラッキングを実装します。

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スレッドの基本

open System.Threading

module ThreadBasics =
    /// Create a worker thread with the given name and task
    let createWorker (name: string) (task: unit -> unit) : Thread =
        let thread = Thread(ThreadStart(task))
        thread.Name <- name
        thread

    /// Create multiple worker threads
    let createMultipleWorkers (count: int) (task: int -> unit) : Thread list =
        [ for i in 0 .. count - 1 do
            let thread = Thread(ThreadStart(fun () -> task i))
            thread.Name <- $"Worker-{i}"
            yield thread ]

    /// Start all threads and wait for them to complete
    let startAndJoinAll (threads: Thread list) : unit =
        threads |> List.iter (fun t -> t.Start())
        threads |> List.iter (fun t -> t.Join())

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並列パスワードクラッキング

Async による並列実行

type ChunkRange = { Start: int; End: int }

module PasswordCrackerParallel =
    /// Divide a range into chunks
    let getChunks (numChunks: int) (totalSize: int) : ChunkRange list =
        let chunkSize = totalSize / numChunks
        let remainder = totalSize % numChunks

        [ for i in 0 .. numChunks - 1 do
            let start = i * chunkSize + min i remainder
            let extraOne = if i < remainder then 1 else 0
            yield { Start = start; End = start + chunkSize + extraOne } ]

    /// Crack password using parallel execution
    let crackPasswordParallel (cryptoHash: string) (length: int) : string option =
        let combinations = getCombinations length
        let numCores = Environment.ProcessorCount
        let chunks = getChunks numCores (List.length combinations)

        let result = ref None
        let combinationsArray = combinations |> List.toArray

        let tasks =
            chunks
            |> List.map (fun chunk ->
                async {
                    let subList = combinationsArray.[chunk.Start .. chunk.End - 1]
                    for password in subList do
                        if Option.isNone !result && checkPassword password cryptoHash then
                            result := Some password
                })

        tasks
        |> Async.Parallel
        |> Async.RunSynchronously
        |> ignore

        !result

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ポイント

• Async ワークフロー: async { ... } で非同期計算を定義
• Async.Parallel: 複数の非同期計算を並列実行
• 参照セル (ref): 可変な共有状態

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次のステップ

Part III では、マルチタスキングとゲームループを学びます。