3

是时候因为对 .NET 中并发的工作原理缺乏了解而再次让自己难堪了：P

我正在尝试编写一个函数，该函数可以封装创建一个异步工作流，该工作流接受 asyncSeq 输入并将其分发给 n 个并行消费者。

let doWorkInParallel bufferSize numberOfConsumers consumer input = async {
    let buffer = BlockingQueueAgent<_>(bufferSize)
    let inputFinished = ref false

    let produce seq = async {
        do! seq |> AsyncSeq.iterAsync (Some >> buffer.AsyncAdd)
        do! buffer.AsyncAdd None
    }

    let consumeParallel degree f = async {
        let consume f = async {
            while not <| !inputFinished do
                try
                    let! data = buffer.AsyncGet(waitTimeout)
                    match data with
                    | Some i -> do! f i
                    // whichever consumer gets the end of the input flips the inputFinished ref so they'll all stop processing
                    | None -> inputFinished := true
                with | :? TimeoutException -> ()
        }

        do! [for slot in 1 .. degree -> consume f ]
            |> Async.Parallel
            |> Async.Ignore
    }

    let startProducer = produce input
    let startConsumers = consumeParallel numberOfConsumers consumer

    return! [| startProducer; startConsumers |] |> Async.Parallel |> Async.Ignore
}

我一直在用这样的代码对其进行测试，以模拟一个快速创建的序列，但每个项目的工作都需要一段时间。

let input = seq {1..50} |> AsyncSeq.ofSeq
let action i = async {
    do! Async.Sleep 500
    printfn "%d GET" i
    }
let test = doWorkInParallel 10 2 action input
Async.RunSynchronously test

编辑：我似乎已经解决了我最初的问题（呃，我真的没有想过我在用 EventWaitHandle 做什么，太傻了），但我仍然很想听听这是否是解决问题的一种完全愚蠢的方法与 F#。

4

0 回答 0