SystemFiberScheduler.cs SpicyPixel::Threading::SystemFiberScheduler SpicyPixel SpicyPixel::Threading /* Author:AaronOneal,http://aarononeal.info Copyright(c)2012SpicyPixel,http://spicypixel.com Permissionisherebygranted,freeofcharge,toanypersonobtaining acopyofthissoftwareandassociateddocumentationfiles(the "Software"),todealintheSoftwarewithoutrestriction,including withoutlimitationtherightstouse,copy,modify,merge,publish, distribute,sublicense,and/orsellcopiesoftheSoftware,andto permitpersonstowhomtheSoftwareisfurnishedtodoso,subjectto thefollowingconditions: Theabovecopyrightnoticeandthispermissionnoticeshallbe includedinallcopiesorsubstantialportionsoftheSoftware. THESOFTWAREISPROVIDED"ASIS",WITHOUTWARRANTYOFANYKIND, EXPRESSORIMPLIED,INCLUDINGBUTNOTLIMITEDTOTHEWARRANTIESOF MERCHANTABILITY,FITNESSFORAPARTICULARPURPOSEAND NONINFRINGEMENT.INNOEVENTSHALLTHEAUTHORSORCOPYRIGHTHOLDERSBE LIABLEFORANYCLAIM,DAMAGESOROTHERLIABILITY,WHETHERINANACTION OFCONTRACT,TORTOROTHERWISE,ARISINGFROM,OUTOFORINCONNECTION WITHTHESOFTWAREORTHEUSEOROTHERDEALINGSINTHESOFTWARE. */ usingSystem; usingSystem.Collections; usingSystem.Collections.Generic; usingSystem.Collections.Concurrent; usingSystem.Threading; namespaceSpicyPixel.Threading { publicclassSystemFiberScheduler:FiberScheduler { publicstaticSystemFiberSchedulerStartNew() { returnStartNew(null,CancellationToken.None,0f); } publicstaticSystemFiberSchedulerStartNew(CancellationTokentoken,floatupdatesPerSecond=0f) { returnStartNew(null,token,updatesPerSecond); } publicstaticSystemFiberSchedulerStartNew(Fiberfiber) { returnStartNew(fiber,CancellationToken.None,0f); } publicstaticSystemFiberSchedulerStartNew(Fiberfiber,CancellationTokentoken,floatupdatesPerSecond=0f) { SystemFiberSchedulerbackgroundScheduler=null; //Setupathreadtorunthescheduler varwait=newManualResetEvent(false); varthread=newThread(()=>{ backgroundScheduler=(SystemFiberScheduler)FiberScheduler.Current; wait.Set(); FiberScheduler.Current.Run(fiber,token,updatesPerSecond); }); thread.Start(); wait.WaitOne(); returnbackgroundScheduler; } privateconstintMaxStackDepth=10; [ThreadStatic] privatestaticintstackDepthQueueFiber=0; privateConcurrentQueue<Fiber>executingFibers=newConcurrentQueue<Fiber>(); privateConcurrentQueue<Tuple<Fiber, float>>sleepingFibers=newConcurrentQueue<Tuple<Fiber, float>>(); //AfuturequeuemayincludewaitingFibers(e.g.waitingonasignalortimeout) privatefloatcurrentTime; privateManualResetEventrunWaitHandle=newManualResetEvent(true); privateManualResetEventdisposeWaitHandle=newManualResetEvent(false); privateAutoResetEventschedulerEventWaitHandle=newAutoResetEvent(false); protectedManualResetEventRunWaitHandle{ get{returnrunWaitHandle;} } protectedWaitHandleDisposeWaitHandle{ get{returndisposeWaitHandle;} } protectedWaitHandleSchedulerEventWaitHandle{ get{returnschedulerEventWaitHandle;} } protectedintExecutingFiberCount{ get{returnexecutingFibers.Count;} } protectedintSleepingFiberCount{ get{returnsleepingFibers.Count;} } publicboolIsRunning{ get;privateset; } publicSystemFiberScheduler() { IsRunning=false; } protectedsealedoverridevoidQueueFiber(Fiberfiber) { //if(!IsRunning){ //thrownewInvalidOperationException("Cannotqueueafiberonanon-runningscheduler"); //} //Queueingcanhappenfromcompletioncallbacks //whichmayhappenoncethefiberhasalready //executedandchangedstate.Itwouldbefine //ifthequeuedidhappenbecausenon-running //fibersareskipped,butit'sbetterto //shortcuthere. if(fiber.Status!=FiberStatus.WaitingToRun&&fiber.Status!=FiberStatus.Running) return; //Enteringqueuefiberwhererecursionmightmatter Interlocked.Increment(refstackDepthQueueFiber); try{ //Executeimmediatelytoinlineasmuchaspossible // //Note:Someapplicationsmaywanttoalwaysqueuetocontrol //performancemorestrictlybytherunloop. if(AllowInlining&&SchedulerThread==Thread.CurrentThread&&stackDepthQueueFiber<MaxStackDepth){ ExecuteFiberInternal(fiber); return; }else{ QueueFiberForExecution(fiber); return; } }finally{ //Exitingqueuefiber Interlocked.Decrement(refstackDepthQueueFiber); } } privatevoidQueueFiberForExecution(Fiberfiber) { executingFibers.Enqueue(fiber); //Queueinganewexecutionfiberneedstotriggerre-evaluationofthe //nextupdatetime schedulerEventWaitHandle.Set(); } privatevoidQueueFiberForSleep(Fiberfiber,floattimeToWake) { vartuple=newTuple<Fiber, float>(fiber,timeToWake); sleepingFibers.Enqueue(tuple); //Fiberscanonlybequeuedforsleepwhentheyreturn //ayieldinstruction.Thiscanonlyhappenwhenexecuting //onthemainthreadandthereforewewillneverbein //awaitloopwithaneedtosignaltheschedulereventhandle. } protectedvoidUpdate(floattime) { currentTime=time; UpdateExecutingFibers(); UpdateSleepingFibers(); } privatevoidUpdateExecutingFibers() { //Runexecutingfibers //Addnulltoknowwhentostop executingFibers.Enqueue(null); Fiberitem; while(executingFibers.TryDequeue(outitem)){ //Ifwereachedthemarkerforthisupdatethenstop if(item==null) break; //Skipcompleteditems if(item.IsCompleted) continue; ExecuteFiberInternal(item); } } privatevoidUpdateSleepingFibers() { //Wakesleepingfibersthatit'stimefor //Addnulltoknowwhentostop sleepingFibers.Enqueue(null); Tuple<Fiber, float>item; while(sleepingFibers.TryDequeue(outitem)){ //Ifwereachedthemarkerforthisupdatethenstop if(item==null) break; Fiberfiber=item.Item1; //Skipcompleteditems if(fiber.IsCompleted) continue; //Runiftimeorcancelledotherwisere-enqueue if(item.Item2<=currentTime||fiber.cancelToken.IsCancellationRequested) ExecuteFiberInternal(item.Item1); else sleepingFibers.Enqueue(item); } } protectedboolGetNextFiberWakeTime(outfloatfiberWakeTime) { fiberWakeTime=-1f; //Nothigtodoiftherearenosleepingfibers if(sleepingFibers.Count==0) returnfalse; //Findtheearliestwaketime foreach(varfiberinsleepingFibers){ if(fiber.Item1.cancelToken.IsCancellationRequested){ fiberWakeTime=0f;//wakeimmediately break; } if(fiberWakeTime==-1f||fiber.Item2<fiberWakeTime) fiberWakeTime=fiber.Item2; } returntrue; } privateIEnumeratorCancelWhenComplete(FiberwaitOnFiber,CancellationTokenSourcecancelSource) { yieldreturnwaitOnFiber; cancelSource.Cancel(); } publicoverridevoidRun(Fiberfiber,CancellationTokentoken,floatupdatesPerSecond) { longfrequencyTicks=(long)(updatesPerSecond*(float)TimeSpan.TicksPerSecond);//mintimebetweenupdates(duration) longstartTicks=0;//startofupdatetime(marker) longendTicks=0;//endofupdatetime(marker) longsleepTicks;//timetosleep(duration) longwakeTicks;//ticksbeforewake(duration) intsleepMilliseconds;//mstosleep(duration) intwakeMilliseconds;//msbeforewake(duration) floatwakeMarkerInSeconds;//timeofwakeinseconds(marker) varmainFiberCompleteCancelSource=newCancellationTokenSource(); if(isDisposed) thrownewObjectDisposedException(GetType().FullName); //Runisnotre-entrant,makesurewe'renotrunning if(!runWaitHandle.WaitOne(0)) thrownewInvalidOperationException("Runisalreadyexecutingandisnotre-entrant"); //Verifyarguments if(updatesPerSecond<0f) thrownewArgumentOutOfRangeException("updatesPerSecond","TheupdatesPerSecondmustbe>=0"); //Getabasetimeforbetterprecision longbaseTicks=DateTime.Now.Ticks; //Buildwaitlisttoterminateexecution varwaitHandleList=newList<WaitHandle>(4); waitHandleList.Add(schedulerEventWaitHandle); waitHandleList.Add(disposeWaitHandle); if(token.CanBeCanceled) waitHandleList.Add(token.WaitHandle); try{ IsRunning=true; if(fiber!=null){ //Addthemainfibertothewaitlistsowhenitcompletes //thewaithandlefallsthrough. waitHandleList.Add(mainFiberCompleteCancelSource.Token.WaitHandle); //Startthemainfiberifitisn'trunningyet if(fiber.Status==FiberStatus.Created) fiber.Start(this); //Startafiberthatwaitsonthemainfibertocomplete. //Whenitdoes,itraisesacancellation. Fiber.Factory.StartNew(CancelWhenComplete(fiber,mainFiberCompleteCancelSource),this); } WaitHandle[]waitHandles=waitHandleList.ToArray(); //FIXME:Unclearwhybelowwasincludedasthehandle //seemstobeneededtowakesleepingfiberswhenabortiscalled. //waitHandleList.Remove(schedulerEventWaitHandle); WaitHandle[]sleepWaitHandles=waitHandleList.ToArray(); runWaitHandle.Reset(); while(true){ //Throwiffaulted if(fiber!=null&&fiber.IsFaulted){ throwfiber.Exception; } //Stopexecutingifcancelled if((token.CanBeCanceled&&token.IsCancellationRequested)||mainFiberCompleteCancelSource.IsCancellationRequested||disposeWaitHandle.WaitOne(0)) return; //Snapcurrenttime startTicks=DateTime.Now.Ticks; //Updateusingthistimemarker(andconverttickstos) Update((float)((double)(startTicks-baseTicks)/(double)TimeSpan.TicksPerSecond)); //Onlysleeptonextfrequencycycleifonewasspecified if(updatesPerSecond>0f){ //Snapendtime endTicks=DateTime.Now.Ticks; //Sleepatleastuntilnextupdate sleepTicks=frequencyTicks-(endTicks-startTicks); if(sleepTicks>0){ sleepMilliseconds=(int)(sleepTicks/TimeSpan.TicksPerMillisecond); WaitHandle.WaitAny(sleepWaitHandles,sleepMilliseconds); //Stopexecutingifcancelled if((token.CanBeCanceled&&token.IsCancellationRequested)||mainFiberCompleteCancelSource.IsCancellationRequested||disposeWaitHandle.WaitOne(0)) return; } } //Nowkeepsleepinguntilit'stimetoupdate while(ExecutingFiberCount==0&&(fiber==null||(fiber!=null&&!fiber.IsFaulted))){ //Assumewewaitforever(e.g.untilasignal) wakeMilliseconds=-1; //Iftherearesleepingfibers,thensetawaketime if(GetNextFiberWakeTime(outwakeMarkerInSeconds)){ wakeTicks=baseTicks; wakeTicks+=(long)((double)wakeMarkerInSeconds*(double)TimeSpan.TicksPerSecond); wakeTicks-=DateTime.Now.Ticks; //Iftherewasawaitingfiberandit'salreadypasttimetoawakethenstopwaiting if(wakeTicks<=0) break; wakeMilliseconds=(int)(wakeTicks/TimeSpan.TicksPerMillisecond); } //FIXME:Sleepingtaskscanbeabortedandthisshouldwakethescheduler. //ForsomereasontheschedulerEventWaitHandlewhichwoulddothiswasnot //inthewaitlistandremovedabove.Tryingwithitinthelistagain. //Therewasnowaitingfiberandwewillwaitforanothersignal, //ortherewasawaitingfiberandwewaituntilthattime. WaitHandle.WaitAny(waitHandles,wakeMilliseconds); //Stopexecutingifcancelled if((token.CanBeCanceled&&token.IsCancellationRequested)||mainFiberCompleteCancelSource.IsCancellationRequested||disposeWaitHandle.WaitOne(0)) return; } } }finally{ //Clearqueues FiberdeqeueFiber; while(executingFibers.TryDequeue(outdeqeueFiber)){} Tuple<Fiber, float>dequeueSleepingFiber; while(sleepingFibers.TryDequeue(outdequeueSleepingFiber)){} //Resettime currentTime=0f; //Notrunning IsRunning=false; //Setfordispose runWaitHandle.Set(); } } privatevoidExecuteFiberInternal(Fiberfiber) { FibercurrentFiber=fiber; FibernextFiber; while(currentFiber!=null){ //Executethefiber varfiberInstruction=ExecuteFiber(currentFiber); //Nothingmoretodoifstopped if(currentFiber.IsCompleted) return; //Handlespecialfiberinstructionsorqueueforanotherupdate boolfiberQueued=false; OnFiberInstruction(currentFiber,fiberInstruction,outfiberQueued,outnextFiber); //Ifthefiberisstillrunningbutwasn'taddedtoaspecialqueueby //aninstructionthenitneedstobeaddedtotheexecutionqueue //toruninthenextUpdate(). // //Checkalivestateagainincaseaninstructionresulted //inaninlineexecutionandalteredstate. if(!fiberQueued&&!currentFiber.IsCompleted){ //Sendthefibertothequeueanddon'texecuteinline //sincewe'redonethisupdate QueueFiberForExecution(currentFiber); } //Switchtothenextfiberifaninstructionsaystodoso currentFiber=nextFiber; } } privatevoidOnFiberInstruction(Fiberfiber,FiberInstructioninstruction,outboolfiberQueued,outFibernextFiber) { fiberQueued=false; nextFiber=null; YieldUntilCompleteyieldUntilComplete=instructionasYieldUntilComplete; if(yieldUntilComplete!=null){ //Theadditionalcomplexitybelowisbecausethiswasgoing //tohandlewaitingforcompletionsforfibersfromotherthreads. //Currentlyfibersmustbelongtothesamethreadandthisisenforced //bytheinstructionsthemselvesfornow. intcompleteOnce=0; //FIXME:Ifwesupportmultipleschedulersinthefuture //thiscallbackcouldoccurfromanotherthreadand //thereforeafterDispose().Wouldprobablyneedalock. yieldUntilComplete.Fiber.ContinueWith((f)=>{ varoriginalCompleteOnce=Interlocked.CompareExchange(refcompleteOnce,1,0); if(originalCompleteOnce!=0) return; QueueFiber(fiber);//optionallyexecuteinlinewhenthecompletionoccurs //Iff.Status!=RanToCompletionthenthisfiberneedstotransitiontothesamestate //orfaultswon'tpropegate //if(f.Status!=FiberStatus.RanToCompletion){ //if(f.IsCanceled){ //if(f.CancellationToken==fiber.CancellationToken){ //fiber.CancelContinuation(); //}else{ //fiber.FaultContinuation(newSystem.Threading.OperationCanceledException()); //} //}elseif(f.IsFaulted){ //fiber.FaultContinuation(f.Exception); //} //RemoveFiberFromQueues(fiber); //}else{ //QueueFiber(fiber);//optionallyexecuteinlinewhenthecompletionoccurs //} }); fiberQueued=true; return; } YieldForSecondsyieldForSeconds=instructionasYieldForSeconds; if(yieldForSeconds!=null){ QueueFiberForSleep(fiber,currentTime+yieldForSeconds.Seconds); fiberQueued=true; return; } YieldToFiberyieldToFiber=instructionasYieldToFiber; if(yieldToFiber!=null){ RemoveFiberFromQueues(yieldToFiber.Fiber); nextFiber=yieldToFiber.Fiber; fiberQueued=false; return; } } privatevoidRemoveFiberFromQueues(Fiberfiber) { boolfound=false; if(executingFibers.Count>0){ FibermarkerItem=newFiber(()=>{}); executingFibers.Enqueue(markerItem); Fiberitem; while(executingFibers.TryDequeue(outitem)){ if(item==markerItem) break; if(item==fiber) found=true; else executingFibers.Enqueue(item); } if(found) return; } if(sleepingFibers.Count>0){ Tuple<Fiber, float>markerTuple=newTuple<Fiber, float>(null,0f); sleepingFibers.Enqueue(markerTuple); Tuple<Fiber, float>itemTuple; while(sleepingFibers.TryDequeue(outitemTuple)){ if(itemTuple==markerTuple) break; if(itemTuple!=null&&itemTuple.Item1==fiber) found=true; else sleepingFibers.Enqueue(itemTuple); } } } #regionIDisposableimplementation privateboolisDisposed=false; protectedoverridevoidDispose(booldisposing) { //Donothingifalreadycalled if(isDisposed) return; if(disposing){ //Freeotherstate(managedobjects). disposeWaitHandle.Set(); runWaitHandle.WaitOne(); } //Freeyourownstate(unmanagedobjects). //Setlargefieldstonull. //Markdisposed isDisposed=true; base.Dispose(disposing); } #endregion } }