TaskContinuation.cs System System::Threading System::Threading::Tasks // //TaskContinuation.cs // //Authors: //JérémieLaval<jeremiedotlavalatxamarindotcom> //MarekSafar<marek.safar@gmail.com> // //Copyright2011XamarinInc(http://www.xamarin.com). // //Permissionisherebygranted,freeofcharge,toanypersonobtainingacopy //ofthissoftwareandassociateddocumentationfiles(the"Software"),todeal //intheSoftwarewithoutrestriction,includingwithoutlimitationtherights //touse,copy,modify,merge,publish,distribute,sublicense,and/orsell //copiesoftheSoftware,andtopermitpersonstowhomtheSoftwareis //furnishedtodoso,subjecttothefollowingconditions: // //Theabovecopyrightnoticeandthispermissionnoticeshallbeincludedin //allcopiesorsubstantialportionsoftheSoftware. // //THESOFTWAREISPROVIDED"ASIS",WITHOUTWARRANTYOFANYKIND,EXPRESSOR //IMPLIED,INCLUDINGBUTNOTLIMITEDTOTHEWARRANTIESOFMERCHANTABILITY, //FITNESSFORAPARTICULARPURPOSEANDNONINFRINGEMENT.INNOEVENTSHALLTHE //AUTHORSORCOPYRIGHTHOLDERSBELIABLEFORANYCLAIM,DAMAGESOROTHER //LIABILITY,WHETHERINANACTIONOFCONTRACT,TORTOROTHERWISE,ARISINGFROM, //OUTOFORINCONNECTIONWITHTHESOFTWAREORTHEUSEOROTHERDEALINGSIN //THESOFTWARE. // // #ifNET_4_0||UNITY_5_3_OR_NEWER usingSystem.Collections.Generic; namespaceSystem.Threading.Tasks { interfaceIContinuation { voidExecute(); } classTaskContinuation:IContinuation { readonlyTasktask; readonlyTaskContinuationOptionscontinuationOptions; publicTaskContinuation(Tasktask,TaskContinuationOptionscontinuationOptions) { this.task=task; this.continuationOptions=continuationOptions; } boolContinuationStatusCheck(TaskContinuationOptionskind) { if(kind==TaskContinuationOptions.None) returntrue; intkindCode=(int)kind; varstatus=task.ContinuationAncestor.Status; if(kindCode>=((int)TaskContinuationOptions.NotOnRanToCompletion)){ //Removeotheroptions kind&=~(TaskContinuationOptions.PreferFairness |TaskContinuationOptions.LongRunning |TaskContinuationOptions.AttachedToParent |TaskContinuationOptions.ExecuteSynchronously); if(status==TaskStatus.Canceled){ if(kind==TaskContinuationOptions.NotOnCanceled) returnfalse; if(kind==TaskContinuationOptions.OnlyOnFaulted) returnfalse; if(kind==TaskContinuationOptions.OnlyOnRanToCompletion) returnfalse; }elseif(status==TaskStatus.Faulted){ if(kind==TaskContinuationOptions.NotOnFaulted) returnfalse; if(kind==TaskContinuationOptions.OnlyOnCanceled) returnfalse; if(kind==TaskContinuationOptions.OnlyOnRanToCompletion) returnfalse; }elseif(status==TaskStatus.RanToCompletion){ if(kind==TaskContinuationOptions.NotOnRanToCompletion) returnfalse; if(kind==TaskContinuationOptions.OnlyOnFaulted) returnfalse; if(kind==TaskContinuationOptions.OnlyOnCanceled) returnfalse; } } returntrue; } publicvoidExecute() { if(!ContinuationStatusCheck(continuationOptions)){ task.CancelReal(); task.Dispose(); return; } //Thetaskmayhavebeencanceledexternally if(task.IsCompleted) return; if((continuationOptions&TaskContinuationOptions.ExecuteSynchronously)!=0) task.RunSynchronouslyCore(task.scheduler); else task.Schedule(); } } classActionContinuation:IContinuation { readonlyActionaction; publicActionContinuation(Actionaction) { this.action=action; } publicvoidExecute() { action(); } } classSynchronizationContextContinuation:IContinuation { readonlyActionaction; readonlySynchronizationContextctx; publicSynchronizationContextContinuation(Actionaction,SynchronizationContextctx) { this.action=action; this.ctx=ctx; } publicvoidExecute() { ctx.Post(l=>((Action)l)(),action); } } sealedclassWhenAllContinuation:IContinuation { readonlyTaskowner; readonlyIList<Task>tasks; intcounter; publicWhenAllContinuation(Taskowner,IList<Task>tasks) { this.owner=owner; this.counter=tasks.Count; this.tasks=tasks; } publicvoidExecute() { if(Interlocked.Decrement(refcounter)!=0) return; owner.Status=TaskStatus.Running; boolcanceled=false; List<Exception>exceptions=null; foreach(vartaskintasks){ if(task.IsFaulted){ if(exceptions==null) exceptions=newList<Exception>(); exceptions.AddRange(task.Exception.InnerExceptions); continue; } if(task.IsCanceled){ canceled=true; } } if(exceptions!=null){ owner.TrySetException(newAggregateException(exceptions)); return; } if(canceled){ owner.CancelReal(); return; } owner.Finish(); } } sealedclassWhenAllContinuation<TResult>:IContinuation { readonlyTask<TResult[]>owner; readonlyIList<Task<TResult>>tasks; intcounter; publicWhenAllContinuation(Task<TResult[]>owner,IList<Task<TResult>>tasks) { this.owner=owner; this.counter=tasks.Count; this.tasks=tasks; } publicvoidExecute() { if(Interlocked.Decrement(refcounter)!=0) return; boolcanceled=false; List<Exception>exceptions=null; TResult[]results=null; for(inti=0;i<tasks.Count;++i){ vartask=tasks[i]; if(task.IsFaulted){ if(exceptions==null) exceptions=newList<Exception>(); exceptions.AddRange(task.Exception.InnerExceptions); continue; } if(task.IsCanceled){ canceled=true; continue; } if(results==null){ if(canceled||exceptions!=null) continue; results=newTResult[tasks.Count]; } results[i]=task.Result; } if(exceptions!=null){ owner.TrySetException(newAggregateException(exceptions)); return; } if(canceled){ owner.CancelReal(); return; } owner.TrySetResult(results); } } sealedclassWhenAnyContinuation<T>:IContinuationwhereT:Task { readonlyTask<T>owner; readonlyIList<T>tasks; AtomicBooleanValueexecuted; publicWhenAnyContinuation(Task<T>owner,IList<T>tasks) { this.owner=owner; this.tasks=tasks; executed=newAtomicBooleanValue(); } publicvoidExecute() { if(!executed.TryRelaxedSet()) return; boolowner_notified=false; for(inti=0;i<tasks.Count;++i){ vartask=tasks[i]; if(!task.IsCompleted){ task.RemoveContinuation(this); continue; } if(owner_notified) continue; owner.TrySetResult(task); owner_notified=true; } } } sealedclassManualResetContinuation:IContinuation,IDisposable { readonlyManualResetEventSlimevt; publicManualResetContinuation() { this.evt=newManualResetEventSlim(); } publicManualResetEventSlimEvent{ get{ returnevt; } } publicvoidDispose() { evt.Dispose(); } publicvoidExecute() { evt.Set(); } } sealedclassCountdownContinuation:IContinuation,IDisposable { readonlyCountdownEventevt; publicCountdownContinuation(intinitialCount) { this.evt=newCountdownEvent(initialCount); } publicCountdownEventEvent{ get{ returnevt; } } publicvoidDispose() { evt.Dispose(); } publicvoidExecute() { evt.Signal(); } } } #endif