我正在玩写像一个非常简单的异步测试框架这样的东西。
但是我认为我遇到了某种限制或错误。抱歉，但我无法在较小的代码库上重现此内容。
这是我想出的基本框架：
module TestRunner
open System
type TestOptions = {
Writer : ConsoleColor -> string -> unit}
type TestResults = {
Time : TimeSpan
Failure : exn option
}
type Test = {
Name : string
Finished : IEvent<TestResults>
SetFinished : TestResults -> unit
TestFunc : TestOptions -> Async<TestResults> }
let createTest name f =
let ev = new Event<TestResults>()
{
Name = name
Finished = ev.Publish
SetFinished = (fun res -> ev.Trigger res)
TestFunc =
(fun options -> async {
let watch = System.Diagnostics.Stopwatch.StartNew()
try
do! f options
watch.Stop()
return { Failure = None; Time = watch.Elapsed }
with exn ->
watch.Stop()
return { Failure = Some exn; Time = watch.Elapsed }
})}
let simpleTest name f =
createTest name (fun options -> f options.Writer)
/// Create a new Test and change the result
let mapResult mapping test =
{ test with
TestFunc =
(fun options -> async {
let! result = test.TestFunc options
return mapping result})}
let writeConsole color f =
let old = System.Console.ForegroundColor
try
System.Console.ForegroundColor <- color
f()
finally
System.Console.ForegroundColor <- old
let printColor color (text:String) =
writeConsole color (fun _ -> Console.WriteLine(text))
type WriterMessage =
| NormalWrite of ConsoleColor * String
| StartTask of AsyncReplyChannel<int> * String
| WriteMessage of int * ConsoleColor * String
| EndTask of int
/// will handle printing jobs for two reasons
/// 1. Nice output grouped by tests (StartTask,WriteMessage,EndTask)
/// 2. Print Summary after all tests finished (NormalWrite)
let writer = MailboxProcessor.Start (fun inbox ->
let currentTask = ref 0
let newHandle (returnHandle:AsyncReplyChannel<int>) =
let handle = System.Threading.Interlocked.Increment currentTask
returnHandle.Reply handle
handle
// the tasks describe which tasks are currently waiting to be processed
let rec loop tasks = async {
let! newTasks =
match tasks with
/// We process the Task with the number t and the name name
| (t, name) :: next ->
inbox.Scan
(fun msg ->
match msg with
| EndTask (endTask) ->
// if the message is from the current task finish it
if t = endTask then
Some (async { return next })
else None
| WriteMessage(writeTask, color, message) ->
if writeTask = t then
Some (async {
printColor color (sprintf "Task %s: %s" name message)
return tasks
})
else None
| StartTask (returnHandle, name) ->
// Start any tasks instantly and add them to the list (because otherwise they would just wait for the resonse)
Some (async {
let handle = newHandle returnHandle
return (List.append tasks [handle, name]) })
| _ -> None)
// No Current Tasks so just start ones or process the NormalWrite messages
| [] ->
inbox.Scan
(fun msg ->
match msg with
| StartTask (returnHandle, name) ->
Some (async {
let handle = newHandle returnHandle
return [handle, name] })
| NormalWrite(color, message) ->
Some (async {
printColor color message
return []
})
| _ -> None)
return! loop newTasks
}
loop [])
/// Write a normal message via writer
let writerWrite color (text:String) =
writer.Post(NormalWrite(color, text))
/// A wrapper around the communication (to not miss EndTask for a StartTask)
let createTestWriter name f = async {
let! handle = writer.PostAndAsyncReply(fun reply -> StartTask(reply, name))
try
let writer color s =
writer.Post(WriteMessage(handle,color,s))
return! f(writer)
finally
writer.Post (EndTask(handle))
}
/// Run the given test and print the results
let testRun t = async {
let! results = createTestWriter t.Name (fun writer -> async {
writer ConsoleColor.Green (sprintf "started")
let! results = t.TestFunc { Writer = writer }
match results.Failure with
| Some exn ->
writer ConsoleColor.Red (sprintf "failed with %O" exn)
| None ->
writer ConsoleColor.Green (sprintf "succeeded!")
return results})
t.SetFinished results
}
/// Start the given task with the given amount of workers
let startParallelMailbox workerNum f =
MailboxProcessor.Start(fun inbox ->
let workers = Array.init workerNum (fun _ -> MailboxProcessor.Start f)
let rec loop currentNum = async {
let! msg = inbox.Receive()
workers.[currentNum].Post msg
return! loop ((currentNum + 1) % workerNum)
}
loop 0 )
/// Runs all posted Tasks
let testRunner =
startParallelMailbox 10 (fun inbox ->
let rec loop () = async {
let! test = inbox.Receive()
do! testRun test
return! loop()
}
loop ())
/// Start the given tests and print a sumary at the end
let startTests tests = async {
let! results =
tests
|> Seq.map (fun t ->
let waiter = t.Finished |> Async.AwaitEvent
testRunner.Post t
waiter
)
|> Async.Parallel
let testTime =
results
|> Seq.map (fun res -> res.Time)
|> Seq.fold (fun state item -> state + item) TimeSpan.Zero
let failed =
results
|> Seq.map (fun res -> res.Failure)
|> Seq.filter (fun o -> o.IsSome)
|> Seq.length
let testCount = results.Length
if failed > 0 then
writerWrite ConsoleColor.DarkRed (sprintf "--- %d of %d TESTS FAILED (%A) ---" failed testCount testTime)
else
writerWrite ConsoleColor.DarkGray (sprintf "--- %d TESTS FINISHED SUCCESFULLY (%A) ---" testCount testTime)
}
现在，仅当我使用一组特定的测试时才触发异常
哪些会在网络上进行爬网（有些会失败，有些则不会，这很好）：
#r @"Yaaf.GameMediaManager.Primitives.dll";; // See below
open TestRunner
let testLink link =
Yaaf.GameMediaManager.EslGrabber.getMatchMembers link
|> Async.Ignore
let tests = [
// Some working links (links that should work)
yield!
[ //"TestMatch", "http://www.esl.eu/eu/wire/anti-cheat/css/anticheat_test/match/26077222/"
"MatchwithCheater", "http://www.esl.eu/de/csgo/ui/versus/match/3035028"
"DeletedAccount", "http://www.esl.eu/de/css/ui/versus/match/2852106"
"CS1.6", "http://www.esl.eu/de/cs/ui/versus/match/2997440"
"2on2Versus", "http://www.esl.eu/de/css/ui/versus/match/3012767"
"SC2cup1on1", "http://www.esl.eu/eu/sc2/go4sc2/cup230/match/26964055/"
"CSGO2on2Cup", "http://www.esl.eu/de/csgo/cups/2on2/season_08/match/26854846/"
"CSSAwpCup", "http://www.esl.eu/eu/css/cups/2on2/awp_cup_11/match/26811005/"
] |> Seq.map (fun (name, workingLink) -> simpleTest (sprintf "TestEslMatches_%s" name) (fun o -> testLink workingLink))
]
startTests tests |> Async.Start;; // this will produce the Exception now and then
https://github.com/matthid/Yaaf.GameMediaManager/blob/core/src/Yaaf.GameMediaManager.Primitives/EslGrabber.fs是代码，您可以下载https://github.com/downloads/matthid/Yaaf.GameMediaManager/GameMediaManager.%200.9.3.1.wireplugin（基本上是一个重命名的zip存档）并将其解压缩以获得Yaaf.GameMediaManager.Primitives.dll二进制文件
（您可以将其粘贴到FSI中，而不是在需要时下载，但必须引用HtmlAgilityPack）
我可以使用Microsoft（R）F＃2.0 Interactive，内部版本4.0.40219.1重现此内容。问题是异常不会总是（但是经常）触发，并且堆栈跟踪没有告诉我任何事情
System.Exception: multiple waiting reader continuations for mailbox
bei <StartupCode$FSharp-Core>[email protected](AsyncParams`1 _arg11)
bei <StartupCode$FSharp-Core>.$Control.loop@413-40(Trampoline this, FSharpFunc`2 action)
bei Microsoft.FSharp.Control.Trampoline.ExecuteAction(FSharpFunc`2 firstAction)
bei Microsoft.FSharp.Control.TrampolineHolder.Protect(FSharpFunc`2 firstAction)
bei <StartupCode$FSharp-Core>.$Control.finishTask@1280[T](AsyncParams`1 _arg3, AsyncParamsAux aux, FSharpRef`1 firstExn, T[] results, TrampolineHolder trampolineHolder, Int32 remaining)
bei <StartupCode$FSharp-Core>.$Control.recordFailure@1302[T](AsyncParams`1 _arg3, AsyncParamsAux aux, FSharpRef`1 count, FSharpRef`1 firstExn, T[] results, LinkedSubSource innerCTS, TrampolineHolder trampolineHolder, FSharpChoice`2 exn)
bei <StartupCode$FSharp-Core>[email protected](Exception exn)
bei Microsoft.FSharp.Control.AsyncBuilderImpl.protectedPrimitive@690.Invoke(AsyncParams`1 args)
bei <StartupCode$FSharp-Core>.$Control.loop@413-40(Trampoline this, FSharpFunc`2 action)
bei Microsoft.FSharp.Control.Trampoline.ExecuteAction(FSharpFunc`2 firstAction)
bei Microsoft.FSharp.Control.TrampolineHolder.Protect(FSharpFunc`2 firstAction)
bei <StartupCode$FSharp-Core>[email protected](Object state)
bei System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
bei System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
bei System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
bei System.Threading.ThreadPoolWorkQueue.Dispatch()
bei System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
因为这将在我无法控制的工作线程上触发，所以这将导致应用程序崩溃（不是FSI，但异常也会在此处显示）。
我找到了http://cs.hubfs.net/topic/Some/2/59152和http://cs.hubfs.net/topic/None/59146，但是我没有使用StartChild，并且我不认为以某种方式同时从多个线程调用Receive？
我的代码有什么问题吗，或者确实是一个错误？如果可能，我该如何解决？
我注意到在FSI中，当无声地忽略Exception时，所有测试将按预期运行。我该怎么做？
编辑：我修复了失败的单元测试后，它会正常工作。但是我不能用较小的代码库重现此问题。例如，我自己的测试失败。
谢谢，matthid
最佳答案
我的感觉是，限制将在MailboxProcessor本身之内，而不是异步的。
老实说，我会谨慎使用扫描功能。我写了blog post关于使用它们的危险。
是否可以使用标准接收机制而不是使用扫描功能来处理任务？
需要注意的是，在异步内部，使用了蹦床，以便同一线程被重用一定时间，以避免不必要的线程池使用（我认为这设置为300），因此在调试时您可能会看到这种行为。
我将以稍微不同的方式将单独的组件分解为管道阶段，而不是嵌套的异步块，以解决此问题。我将创建一个主管组件和路由组件。
主管将负责初始测试，并将消息发布到路由组件，该组件将请求轮流到其他代理。任务完成后，他们可以发回主管。
我意识到这并不能真正解决当前代码中的问题，但是我认为您仍然必须分解问题才能调试系统的异步部分。