SpinWait.cs System::Threading::SpinWait System System::Threading //SpinWait.cs // //Copyright(c)2008Jérémie"Garuma"Laval // //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; namespaceSystem.Threading { publicstructSpinWait { //ThenumberofstepuntilSpinOnceyieldonmulticoremachine constintstep=10; constintmaxTime=200; staticreadonlyboolisSingleCpu=(Environment.ProcessorCount==1); intntime; publicvoidSpinOnce() { ntime+=1; if(isSingleCpu){ //Onasingle-CPUsystem,spinningdoesnogood Yield(); }else{ if(ntime%step==0) Yield(); else //Multi-CPUsystemmightbehyper-threaded,letotherthreadrun Thread.SpinWait(Math.Min(ntime,maxTime)<<1); } } //SpicyPixel:Thread.Yield()isnotsupportedin.NET<4 constints1step=20; ints1time; voidYield() { //Replacesched_yieldbyThread.Sleep(0)whichdoesalmostthesamething //(goingbackinkernelmodeandyielding)butavoidthebranchingandunmanagedbridge //Thread.Sleep(0);//Thread.Yield()isbetter /* http://stackoverflow.com/questions/1413630/switchtothread-thread-yield-vs-thread-sleep0-vs-thead-sleep1 SwitchToThread[win32]/Thread.Yield[.NET4Beta1]:yieldstoanythreadonsameprocessor Advantage:abouttwiceasfastasThread.Sleep(0) Disadvantage:yieldsonlytothreadsonsameprocessor Thread.Sleep(0):yieldstoanythreadofsameorhigherpriorityonanyprocessor Advantage:fasterthanThread.Sleep(1) Disadvantage:yieldsonlytothreadsofsameorhigherpriority Thread.Sleep(1):yieldstoanythreadonanyprocessor Advantage:yieldstoanythreadonanyprocessor Disadvantage:slowestoption(Thread.Sleep(1)willusuallysuspendthethreadbyabout15msiftimeBeginPeriod/timeEndPeriod[win32]arenotused) */ //BecauseSleep(1)pullsusoutofthequeuefor10-15msorso, //don'tdoitthatoften. s1time+=1; if(s1time%s1step==0) Thread.Sleep(1); else Thread.Sleep(0); } publicstaticvoidSpinUntil(Func<bool>condition) { SpinWaitsw=newSpinWait(); while(!condition()) sw.SpinOnce(); } publicstaticboolSpinUntil(Func<bool>condition,TimeSpantimeout) { returnSpinUntil(condition,(int)timeout.TotalMilliseconds); } publicstaticboolSpinUntil(Func<bool>condition,intmillisecondsTimeout) { SpinWaitsw=newSpinWait(); Watchwatch=Watch.StartNew(); while(!condition()){ if(watch.ElapsedMilliseconds>millisecondsTimeout) returnfalse; sw.SpinOnce(); } returntrue; } publicvoidReset() { ntime=0; s1time=0; } publicboolNextSpinWillYield{ get{ returnisSingleCpu?true:ntime%step==0; } } publicintCount{ get{ returnntime; } } } } #endif