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Async.Sleep with immediate cancellation
Implementation of Async.Sleep in f# 2.0 doesn't allow break it execution until the time elapsed. Here is the alternate implementation which support immediate cancellation. According to discussion http://stackoverflow.com/questions/9041491/is-there-any-reason-why-async-sleep-can-not-be-canceled-immediately .
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module async_sleep_fix
open System
open System.Collections
open System.Collections.Generic
open System.Reactive.Concurrency
open System.Reactive.Disposables
open System.Threading
open System.Threading.Tasks
type Async with
static member SleepEx(milliseconds:int) = async{
if milliseconds > 0 then
let disp = new SerialDisposable()
use! ch = Async.OnCancel(fun()->disp.Dispose())
do! Async.FromContinuations(fun (success, error, cancel) ->
let timerSubscription = new SerialDisposable()
let CompleteWith =
let completed = ref 0
fun cont ->
if Interlocked.Exchange(completed, 1) = 0 then
timerSubscription.Dispose()
try cont() with _->()
disp.Disposable <- Disposable.Create(fun()->
CompleteWith (fun ()-> cancel(new OperationCanceledException()))
)
let tmr = new Timer(
callback = (fun state -> CompleteWith(success)),
state = null, dueTime = milliseconds, period = Timeout.Infinite
)
if tmr = null then
CompleteWith(fun ()->error(new Exception("failed to create timer")))
else
timerSubscription.Disposable <- Disposable.Create(fun()->
try tmr.Dispose() with _ -> ()
)
)
else
return ()
}
|
module async_sleep_fix
namespace System
namespace System.Collections
namespace System.Collections.Generic
namespace System.Threading
namespace System.Threading.Tasks
Multiple items
type Async
static member AsBeginEnd : computation:('Arg -> Async<'T>) -> ('Arg * AsyncCallback * obj -> IAsyncResult) * (IAsyncResult -> 'T) * (IAsyncResult -> unit)
static member AwaitEvent : event:IEvent<'Del,'T> * ?cancelAction:(unit -> unit) -> Async<'T> (requires delegate and 'Del :> Delegate)
static member AwaitIAsyncResult : iar:IAsyncResult * ?millisecondsTimeout:int -> Async<bool>
static member AwaitTask : task:Task<'T> -> Async<'T>
static member AwaitWaitHandle : waitHandle:WaitHandle * ?millisecondsTimeout:int -> Async<bool>
static member CancelDefaultToken : unit -> unit
static member Catch : computation:Async<'T> -> Async<Choice<'T,exn>>
static member FromBeginEnd : beginAction:(AsyncCallback * obj -> IAsyncResult) * endAction:(IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg:'Arg1 * beginAction:('Arg1 * AsyncCallback * obj -> IAsyncResult) * endAction:(IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg1:'Arg1 * arg2:'Arg2 * beginAction:('Arg1 * 'Arg2 * AsyncCallback * obj -> IAsyncResult) * endAction:(IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromBeginEnd : arg1:'Arg1 * arg2:'Arg2 * arg3:'Arg3 * beginAction:('Arg1 * 'Arg2 * 'Arg3 * AsyncCallback * obj -> IAsyncResult) * endAction:(IAsyncResult -> 'T) * ?cancelAction:(unit -> unit) -> Async<'T>
static member FromContinuations : callback:(('T -> unit) * (exn -> unit) * (OperationCanceledException -> unit) -> unit) -> Async<'T>
static member Ignore : computation:Async<'T> -> Async<unit>
static member OnCancel : interruption:(unit -> unit) -> Async<IDisposable>
static member Parallel : computations:seq<Async<'T>> -> Async<'T []>
static member RunSynchronously : computation:Async<'T> * ?timeout:int * ?cancellationToken:CancellationToken -> 'T
static member Sleep : millisecondsDueTime:int -> Async<unit>
static member Start : computation:Async<unit> * ?cancellationToken:CancellationToken -> unit
static member StartAsTask : computation:Async<'T> * ?taskCreationOptions:TaskCreationOptions * ?cancellationToken:CancellationToken -> Task<'T>
static member StartChild : computation:Async<'T> * ?millisecondsTimeout:int -> Async<Async<'T>>
static member StartChildAsTask : computation:Async<'T> * ?taskCreationOptions:TaskCreationOptions -> Async<Task<'T>>
static member StartImmediate : computation:Async<unit> * ?cancellationToken:CancellationToken -> unit
static member StartWithContinuations : computation:Async<'T> * continuation:('T -> unit) * exceptionContinuation:(exn -> unit) * cancellationContinuation:(OperationCanceledException -> unit) * ?cancellationToken:CancellationToken -> unit
static member SwitchToContext : syncContext:SynchronizationContext -> Async<unit>
static member SwitchToNewThread : unit -> Async<unit>
static member SwitchToThreadPool : unit -> Async<unit>
static member TryCancelled : computation:Async<'T> * compensation:(OperationCanceledException -> unit) -> Async<'T>
static member CancellationToken : Async<CancellationToken>
static member DefaultCancellationToken : CancellationToken
Full name: Microsoft.FSharp.Control.Async
--------------------
type Async<'T>
Full name: Microsoft.FSharp.Control.Async<_>
static member Async.SleepEx : milliseconds:int -> Async<unit>
Full name: async_sleep_fix.SleepEx
val milliseconds : int
Multiple items
val int : value:'T -> int (requires member op_Explicit)
Full name: Microsoft.FSharp.Core.Operators.int
--------------------
type int = int32
Full name: Microsoft.FSharp.Core.int
--------------------
type int<'Measure> = int
Full name: Microsoft.FSharp.Core.int<_>
val async : AsyncBuilder
Full name: Microsoft.FSharp.Core.ExtraTopLevelOperators.async
val disp : obj
val ch : IDisposable
static member Async.OnCancel : interruption:(unit -> unit) -> Async<IDisposable>
static member Async.FromContinuations : callback:(('T -> unit) * (exn -> unit) * (OperationCanceledException -> unit) -> unit) -> Async<'T>
val success : (unit -> unit)
val error : (exn -> unit)
val cancel : (OperationCanceledException -> unit)
val timerSubscription : obj
val CompleteWith : ((unit -> unit) -> unit)
val completed : int ref
Multiple items
val ref : value:'T -> 'T ref
Full name: Microsoft.FSharp.Core.Operators.ref
--------------------
type 'T ref = Ref<'T>
Full name: Microsoft.FSharp.Core.ref<_>
val cont : (unit -> unit)
type Interlocked =
static member Add : location1:int * value:int -> int + 1 overload
static member CompareExchange : location1:int * value:int * comparand:int -> int + 6 overloads
static member Decrement : location:int -> int + 1 overload
static member Exchange : location1:int * value:int -> int + 6 overloads
static member Increment : location:int -> int + 1 overload
static member Read : location:int64 -> int64
Full name: System.Threading.Interlocked
Interlocked.Exchange<'T (requires reference type)>(location1: byref<'T>, value: 'T) : 'T
Interlocked.Exchange(location1: byref<nativeint>, value: nativeint) : nativeint
Interlocked.Exchange(location1: byref<obj>, value: obj) : obj
Interlocked.Exchange(location1: byref<float>, value: float) : float
Interlocked.Exchange(location1: byref<float32>, value: float32) : float32
Interlocked.Exchange(location1: byref<int64>, value: int64) : int64
Interlocked.Exchange(location1: byref<int>, value: int) : int
Multiple items
type OperationCanceledException =
inherit SystemException
new : unit -> OperationCanceledException + 5 overloads
member CancellationToken : CancellationToken with get, set
Full name: System.OperationCanceledException
--------------------
OperationCanceledException() : unit
OperationCanceledException(message: string) : unit
OperationCanceledException(token: CancellationToken) : unit
OperationCanceledException(message: string, innerException: exn) : unit
OperationCanceledException(message: string, token: CancellationToken) : unit
OperationCanceledException(message: string, innerException: exn, token: CancellationToken) : unit
val tmr : Timer
Multiple items
type Timer =
inherit MarshalByRefObject
new : callback:TimerCallback -> Timer + 4 overloads
member Change : dueTime:int * period:int -> bool + 3 overloads
member Dispose : unit -> unit + 1 overload
Full name: System.Threading.Timer
--------------------
Timer(callback: TimerCallback) : unit
Timer(callback: TimerCallback, state: obj, dueTime: int, period: int) : unit
Timer(callback: TimerCallback, state: obj, dueTime: TimeSpan, period: TimeSpan) : unit
Timer(callback: TimerCallback, state: obj, dueTime: uint32, period: uint32) : unit
Timer(callback: TimerCallback, state: obj, dueTime: int64, period: int64) : unit
val state : obj
type Timeout =
static val Infinite : int
Full name: System.Threading.Timeout
field Timeout.Infinite = -1
Multiple items
type Exception =
new : unit -> Exception + 2 overloads
member Data : IDictionary
member GetBaseException : unit -> Exception
member GetObjectData : info:SerializationInfo * context:StreamingContext -> unit
member GetType : unit -> Type
member HelpLink : string with get, set
member InnerException : Exception
member Message : string
member Source : string with get, set
member StackTrace : string
...
Full name: System.Exception
--------------------
Exception() : unit
Exception(message: string) : unit
Exception(message: string, innerException: exn) : unit
Timer.Dispose() : unit
Timer.Dispose(notifyObject: WaitHandle) : bool
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