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// (c) Microsoft Corporation 2005-2009.
namespace Microsoft.FSharp.Control
open System
open System.Threading
open System.IO
open Microsoft.FSharp.Control
open Microsoft.FSharp.Collections
#if FX_NO_SYNC_CONTEXT
#else
type AsyncWorker<'T>(p : Async<'T>,?cancellationToken) =
let cts =
match cancellationToken with
| None -> new CancellationTokenSource()
| Some token ->
let cts = new CancellationTokenSource()
CancellationTokenSource.CreateLinkedTokenSource(token,cts.Token)
let mutable syncContext : SynchronizationContext = null
// A standard helper to raise an event on the GUI thread
let raiseEventOnGuiThread (event:Event<_>) args =
syncContext.Post((fun _ -> event.Trigger args),state=null)
// Trigger one of the following events when the iteration completes.
let completed = new Event<'T>()
let error = new Event<_>()
let canceled = new Event<_>()
let progress = new Event<int>()
let doWork() =
Async.StartWithContinuations
( p,
(fun res -> raiseEventOnGuiThread completed res),
(fun exn -> raiseEventOnGuiThread error exn),
(fun exn -> raiseEventOnGuiThread canceled exn ),cts.Token)
member x.ReportProgress(progressPercentage) =
raiseEventOnGuiThread progress progressPercentage
member x.RunAsync() =
match syncContext with
| null -> ()
| _ -> invalidOp "The operation is already in progress. RunAsync can't be called twice"
syncContext <-
match SynchronizationContext.Current with
| null -> new SynchronizationContext()
| ctxt -> ctxt
ThreadPool.QueueUserWorkItem(fun args -> doWork())
member x.CancelAsync(?message:string) =
cts.Cancel()
member x.ProgressChanged = progress.Publish
member x.Completed = completed.Publish
member x.Canceled = canceled.Publish
member x.Error = error.Publish
#endif
|
