kc第講并發(fā)控制技術

第17講:(第16章)

并發(fā)控制技術

重慶大學計算機學院課程名稱:數據庫系統(tǒng)

--------------------第17講:并發(fā)控制技術項目驅動目標：

關系數據庫如何實現(xiàn)對多個應用并發(fā)訪問的控制：一、基于鎖的協(xié)議 二、多粒度 三、死鎖處理 四、基于時間戳的協(xié)議 主要討論問題：什么是鎖，有哪些基本類型？什么叫死鎖？什么是兩階段封鎖協(xié)議？除X,S鎖外,還有其它類型的鎖？意向鎖的相容關系如何？如何檢測是否存在死鎖？什么是時間戳協(xié)議？時間戳協(xié)議為何能保持可串行化？Exercise17LocksandItstypesAlockisamechanismtocontrolconcurrentaccesstoadataitemDataitemscanbelockedintwomodes:排它鎖exclusive(X)mode.Dataitemcanbebothreadaswellaswritten.X-lockisrequestedusinglock-Xinstruction.共享鎖shared(S)mode.Dataitemcanonlyberead.S-lockisrequestedusinglock-Sinstruction.Lockrequestsaremadetoconcurrency-controlmanager.Transactioncanproceed繼續(xù)進行

onlyafterrequestisgranted.一基于鎖的協(xié)議1-1什么是鎖，有哪些基本類型？1.1鎖Lock-compatibility相容矩陣：Lock-compatibilitymatrix作用：AtransactionmaybegrantedalockonanitemiftherequestedlockiscompatiblewithlocksalreadyheldontheitembyothertransactionsAnynumberoftransactionscanholdsharedlocksonanitem,butifanytransactionholdsanexclusiveontheitemnoothertransactionmayholdanylockontheitem.Ifalockcannotbegranted,therequestingtransactionismadetowaittillallincompatiblelocksheldbyothertransactionshavebeenreleased.Thelockisthengranted.直觀例示(例子)1-2什么是鎖的相容性？1.1鎖ExampleofUsingLocksExampleofatransactionperforminglocking:

T2:lock-S(A);read(A);unlock(A);lock-S(B);read(B);unlock(B);display(A+B)Lockingasaboveisnotsufficienttoguaranteeserializability,ifAandBgetupdated(bysomeothertransactionT1:轉賬50)in-betweenthereadsofAandB,thedisplayedsumwouldbewrong.Alockingprotocolisasetofrulesfollowedbyalltransactionswhilerequestingandreleasinglocks.Lockingprotocolsrestrict限制

thesetofpossibleschedules.1-3什么是封鎖協(xié)議？T1:lock-X(B);read(B);B:=B-50;write(B);unlock(B);Lock-X(A)read(A)A:=A+50write(A)unlock(A)若：Ais100Bis200則該調度后T2顯示：A+B=150------------而T1,T2后T2顯示300而T2,T1后T2顯示300(原因分析)1.1鎖Pitfalls陷阱ofLock-BasedProtocols-死鎖Considerthepartialschedule

Neither

T3

nor

T4canmakeprogress—executinglock-S(B)causesT4towaitforT3toreleaseitslockonB,whileexecutinglock-X(A)causesT3

towaitforT4toreleaseitslockonA.Suchasituationiscalledadeadlock.死鎖，問題如何解決？TohandleadeadlockoneofT3orT4mustberolledbackand

itslocksreleased.1-4什么叫死鎖？1.2死鎖與活鎖PitfallsofLock-BasedProtocols-活鎖Thepotential潛在的

fordeadlockexistsinmostlockingprotocols.Deadlocksareanecessaryevil不可避免的惡魔.Starvation

饑餓/餓死

isalsopossibleifconcurrencycontrolmanagerisbadlydesigned.Forexample:AtransactionmaybewaitingforanX-lockonanitem,whileasequenceofothertransactionsrequestandaregrantedanS-lockonthesameitem.Thesametransactionisrepeatedlyrolledbackduetodeadlocks.Concurrencycontrolmanagercanbedesignedtopreventstarvation.

(如何解決?)當事務T申請對數據項Q加M型鎖時：當前不存在已對數據項Q持有與M沖突的鎖的其他事務當前不存在(先于T申請)正等待對數據項Q加鎖的其他事務1-5什么叫活鎖(餓死)？1.2死鎖與活鎖TheTwo-PhaseLockingProtocolThisisaprotocolwhichensuresconflict-serializableschedules.第1階段Phase1:增長GrowingPhasetransactionmayobtainlocks,but

加鎖階段！transactionmaynotreleaselocks第2階段Phase2:縮減ShrinkingPhasetransactionmayreleaselocks,but釋放鎖階段！transactionmaynotobtainlocks例子(p.421圖16-5和16-6中的T3和T4都是兩階段的p.420圖16-2和16-3中的T1和T2都不是兩階段的)Theprotocolassuresserializability.Itcanbeprovedthatthetransactionscanbeserializedintheorderoftheirlockpoints

(i.e.thepointwhereatransactionacquireditsfinallock)(留作練習,習題16.1).1.3兩階段封鎖協(xié)議1-6什么是兩階段封鎖協(xié)議？Strict&RigorousTwo-PhaseLockingProtocolTwo-phaselockingdoesnotensurefreedomfromdeadlocks(圖16-7調度2)Cascadingroll-backispossibleundertwo-phaselocking.

(圖16-8,T5撤銷時T6,T7撤銷)Toavoidthis,followamodifiedprotocolcalledstricttwo-phaselocking.Hereatransactionmustholdallitsexclusivelockstillitcommits/aborts.Rigoroustwo-phaselockingisevenstricter:hereall

locksareheldtillcommit/abort.Inthisprotocoltransactionscanbeserializedintheorderinwhichtheycommit.說明：大部分數據庫系統(tǒng)都采用這兩種封鎖協(xié)議之一！p.422圖16-8部分調度1-7什么是嚴格兩階段封鎖協(xié)議？1-8什么是強兩階段封鎖協(xié)議？1.3兩階段封鎖協(xié)議ImplementationofLockingAlockmanagercanbeimplementedasaseparateprocesstowhichtransactionssendlockandunlockrequestsThelockmanagerrepliestoalockrequestbysendingalockgrantmessages(oramessageaskingthetransactiontorollback,incaseofadeadlock)TherequestingtransactionwaitsuntilitsrequestisansweredThelockmanagermaintainsadata-structurecalledalocktabletorecordgrantedlocksandpendingrequestsThelocktableisusuallyimplementedasanin-memoryhashtableindexedonthenameofthedataitembeinglockedlocktable1.4鎖管理器1-9封鎖管理如何實現(xiàn)？LockTableBlackrectanglesindicategrantedlocks,whiteonesindicatewaitingrequestsLocktablealsorecordsthetype

(圖中未標出)oflockgrantedorrequestedNewrequestisaddedtotheendofthequeueofrequestsforthedataitem,andgrantedifitiscompatiblewithallearlierlocksUnlockrequestsresultintherequestbeingdeleted,andlaterrequestsarecheckedtoseeiftheycannowbegrantedIftransactionaborts,allwaitingorgrantedrequestsofthetransactionaredeletedlockmanagermaykeepalistoflocksheldbyeachtransaction,toimplementthisefficiently數據項的hash鏈表當前有五個數據項:I7,I23,I192,I4,I44有相同hash的數據項GrantedWaiting1-10什么是鎖表,有何用途？1.4鎖管理器MultipleGranularity粒度Allowdataitemstobeofvarioussizesanddefineahierarchyofdatagranularities,wherethesmallgranularitiesarenestedwithinlargeronesCanberepresentedgraphicallyasatree(例子)Whenatransactionlocksanodeinthetreeexplicitly,itimplicitlylocksallthenode'sdescendentsinthesamemode.Granularityoflocking(levelintreewherelockingisdone):細粒度鎖finegranularity(lowerintree):highconcurrency,highlockingoverhead粗粒度鎖coarsegranularity

(higherintree):lowlockingoverhead,lowconcurrency二多粒度2.1數據粒度與封鎖2-1什么是數據粒度？2-2多粒度數據如何封鎖？ExampleofGranularityHierarchy

Thelevels,startingfromthecoarsest(top)levelareDatabaseAreaFilerecord

數據庫級區(qū)域級文件級記錄級2.1數據粒度與封鎖IntentionLockModes例子(意向所用途分析)intentionlocksallowahigherlevelnodetobelockedinSorXmodewithouthavingtocheckalldescendentnodes.InadditiontoSandXlockmodes,therearethreeadditionallockmodeswithmultiplegranularity:intention-shared(IS)共享意向鎖:indicatesexplicitlockingatalowerlevelofthetreebutonlywithsharedlocks.低層有顯示S鎖intention-exclusive(IX)排它意向鎖:indicatesexplicitlockingatalowerlevelwithexclusiveorsharedlocks.低層有顯示X/S鎖sharedandintention-exclusive(SIX)共享排它意向鎖:thesubtreerootedbythatnodeislockedexplicitlyinshared

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andexplicitlockingisbeingdoneatalowerlevelwithexclusive-modelocks.意向鎖相容矩陣多粒度封鎖協(xié)議2.2意向鎖2-3除X,S鎖外,還有其它類型的鎖？GranularityHierarchy-用途分析2-4為何需要意向鎖？2.2意向鎖之后,Tk可以對DB加鎖？需檢查所有節(jié)點,搜索整個樹!解決辦法：Ti可對Fc加顯示鎖時，同時對到根路徑的所有父節(jié)點加意向鎖！然后利用多粒度封鎖協(xié)議判斷是否可加鎖！假設：Ti已對Fc加鎖Ti已同時對DB和A2加意向鎖！Co碰mp姐at昆ib迎il去it避y巴Ma宜tr肥ix毫w慚it廁h港I問nt但en具ti撈on沖L根oc收k瞇Mo嬸de鍛sTh議e泉co氣mp哄at笨ib旦il年it離y良ma鳴tr病ix候f誕or賽a砍ll漏l貞oc棍k顛mo什de摸s擇is油:ISIXSSIXXISIXSSIXX2-落5意向購鎖的芽相容頁關系廣如何陸？2.拾2意向潑鎖Mu題lt努ip根le帶G銜ra警nu雪la帳ri帥ty蘋L紹oc烈ki屢ng橋S旗ch沾em饅e多粒倦封度膨鎖協(xié)蛋議:T禍ra憶ns題ac撲ti蹦onTica揭n月lo爭ck柴a爐n鴉od減eQ,刪us陸in處g興th芹e閣fo良ll夾ow詳in架g淹ru寇le養(yǎng)s:Th立e稈lo祖ck胃c偶om距pa爪ti裝bi味li尚ty咽m育at即ri施x埋mu哭st位b門e腎ob傾se轎rv料ed濃.Th南e道ro翼ot計o閘f能th悲e噴tr醒ee狹m貼us哭t惡be野l(fā)森oc叼ke仰d路fi鞏rs道t,淹a歐nd取m鄭ay尸b宜e良lo旗ck圍ed臨i瞞n速an據y螺mo岸de影.A伯no泄deQca軌n侵be禽l早oc博ke傻d象byTiin偵S倦o加r昏IS盲m襲od宅e訪on鋼ly箭i抵f購th埋e輛pa放re叫nt卡o速fQis眉c梁ur犧re輔nt濟ly上l灑oc矮ke遮d輩byTiin漫e錘it松he嚷r朵IX填o針r寬IS恢m辨od桐e.A腸no講deQca剖n陳be膽l許oc蝕ke替d布byTiin抱X每,竊SI愧X,伏o靈r織IX雄m斥od華e善on懷ly旬i肉f豪th獨e襪pa倍re滿nt產o逆fQis哲c青ur墨re抽nt蠟ly涉l駱oc適ke詢d步byTiin近e澇it劑he粒r牧IX淘o退r刺SI綠X痛mo徑de吹.Tica膏n淡lo伯ck級a抬n熊od們e漢on辦ly代i絨f忘it芝h標as約n披ot香p有re真vi宇ou惱sl喚y客un墨lo寇ck多ed剝a夾ny念n煉od稼e萄(t高ha欲t身is掙,Tiis塌t墳wo有-p滲ha司se券).Tica哨n甜un鵝lo子ck衛(wèi)a喘n亦od羅eQon士ly蹄i呈f狂no佳ne丈o壘f唱th形e酷ch甲il豎dr垮en仙o蘇fQar冤e按cu錯rr魄en猶tl節(jié)y蝴lo蔬ck峰ed左b正yTi.特點洞：Ob頃se伙rv敞eth響at防l陶oc織ks判a姻re輩a紡cq遵ui色re犬d獲得inro圈ot燈-t培o-拖le旅af壤o絞rd身er佛,錦wh績er倉ea偷s換th今ey農a把re項r抱el痰ea刷se板d應in拔l敘ea摘f-靈to領-r娘oo躲t擇or件de急r.2-攏6什么雁是多獨粒度依封鎖扇協(xié)議吵？2.娃2意向話鎖De躲ad果lo勵ck-例子Co傷ns聚id喂er濁t(yī)遭he賽f壩ol赴l(fā)o畫wi巖ng貞t雀wo咽t返ra票ns侄ac資ti閃on柱s:T1:筐wr荷it詞e珠(X)T2:景w勉ri散te煙(Y)wr鞠it煩e(Y)由wr雪it娘e(X)Sc敲he深du陜le昏w毀it阻h尿de帽ad迎lo肺ckT1T2lock-XonXwrite(X)lock-XonYwrite(Y)waitforlock-XonXwaitforlock-XonY三買死鎖校處理3.監(jiān)1死鎖3-矩1何時籠會出拼現(xiàn)死蔥鎖？De速ad顯lo斧ck嚴H運an附dl機in袖gSy研st敵em室i跨sde禁ad竿lo速ck敬edifth菊er根e殖is緒a隨s互et飛o壁f營tr貼an蹲sa淚ct請io累ns船s助uc糾h桌th漁atev軌er勁ytr序an殲sa期ct孤io冤n貢in結t繭he瞧s引et枝i齒s缸wa臭it量in退g嫌fo得r財an梢ot養(yǎng)he兆r執(zhí)tr砍an倒sa敬ct岔io器n辨in悟t葉he咱s危et屋.De腸ad完lo拐ck西p橋re客ve戲nt次io愿npr振ot撞oc越ol掛sen肚su回re心t汽ha咳t玩th既e殺sy米st鎮(zhèn)em撞w煩il架lne排ve鴉ren圓te割r肺in繁to傍a廈d失ea條dl坊oc繭k斗st沈at或e.So遮mepr杯ev刺en艘ti英on卻s囑tr撤at最eg奇ie洽s猛:法1：Re山qu窄ir認eth收at鍛e巡壽ac叨h痛tr節(jié)an犬sa妹ct愿io填n瘡lo頃ck雙sal祖lit炎s夕da廉ta殼i袍te提ms缸b規(guī)ef蹲or秘e元it襲b拌eg丙in鳥s歲ex期ec也ut當io訪n愚(p琴re桶de父cl唐ar假at劍io融n).預先惕聲明法2：Im偉po栽se強制pa婆rt次ia稍l墓or譜de偵ri斑ng支o冊fal宵lda榮ta休i營te泊msan銀dre讓qu觀ir蠢e雪th采at程a景t則ra井ns忌ac月ti界on賭c佳an檔l焰oc光k膏da草ta連i爹te此ms樣o午nl炎yin膛t筆he箭o君rd頌ersp娛ec回if嫁ie裂d讀by執(zhí)t汪he溪p悼ar蛋ti參al幟o洲rd查er質(嶼gr忽ap乒h-深ba海se高d孫pr梢ot廢oc驢ol).基于揚圖的摘協(xié)議(p垂.4況24漂)3.強2死鎖鳴預防3-討2如何攪預防便死鎖靈？Mo剩re榜D膝ea傅dl肝oc麥k跑Pr濤ev它en庸ti旺on螺S慨tr美at成eg緒ie略sFo壺ll景ow魚in枕g共sc和he狂me脖s珠us頌e驅tr征an姨sa督ct嚇io成nti寬me鞭st男am友ps時間濾戳fo脂r扁th委e定sa霉ke培o矩f炊de老ad強lo特ck處p歉re抵ve哭nt來io孩n登al濕on抖e.法1）wa妄it疲-d席iesc軍he筐me崗—no矛n-先pr課ee封mp原ti帝ve非搶寒占式ol掉de砌r碌tr歐an須sa宏ct閣io咳n汽ma罰ywa類itfo草r繩yo愁un冰ge毀r它on唇e術to機r敵el稱ea綠se多d使at鑰a素it申em飼.Yo奧un劫ge撐r異tr么an呀sa外ct升io封ns舅n惑ev伏er勤w峽ai減tfo香r輸ol繡de陷ron歉es活(屈th單eyar府e尤ro忍ll票ed生b注ac架kin材st獅ea綢d)胃.躍(有沖乳突時撇，新竊的事潛物自線動回莊卷)a正tr提an熊sa鄭ct富io辨n桃ma陷y去di嬸ese膚ve責ra刃l(wèi)ti巷me訴s俱be司fo士re斬a鼠cq央ui銀ri智ng罰n膀ee維de鄉(xiāng)豐d泰da洲ta磨i患te孝m法2）wo排un含d-膊wa碧itsc顏he凱me木—pr丈ee泰mp吼ti饒ve搶占贏式ol確de僵r賊tr仿an圾sa吧ct趙io它nwo救un屑ds(f桶or換ce紙s比ro船ll焦ba頌ck粱)競of夠y鈔ou左ng跪er題t只ra史ns摸ac扶ti斧on散i瓜ns儀te希ad寸o參f仔wa牢it氣in英g率fo胡r晨it擾.Yo鋒un瓜ge字r俘tr套an螺sa焰ct殲io唱ns免m哲ay姥w桂ai扶tfo盤r售ol竿de會ron糠es械.泳(有沖美突時程，老諸的事廈物強娛制將禿新的編事物差回卷)ma士y某befe策we仇rro沈ll扁ba萌ck江s頓th堡anwa波it匠-d峽iesc累he譯me黑.法3）（待續(xù)…）3-把3還有桃其他安預防品死鎖盈方法版？3.映2死鎖融預防說明涉：Bo仗thinwa哭it燥-d眠iean較d暗inwo闖un品d-券wa姐itsc助he價me錄s,方a湖r沙ol麗le勝d五ba碰ck漆t(yī)彩ra筍ns問ac拌ti趨on輸s觸is階r濤es冬ta育rt擴ed翅w旨it幫h豆it嫩s賺or庸ig扶in步al暑t抓im餓es油ta衣mp永.蜘Ol赴de樓r且tr伍an敵sa厚ct雪io液ns毫t雷hu掀s字ha成ve銀p易re序ce窗de手nc尊e罪ov放er勻n災ew桂er憂o悔ne戚s,膀a閘ndst栽ar碎va能ti講on活鎖is明h康en芬ce毅a棗vo躍id稈ed村.法3）Ti鬼me堆ou鞠t-浩Ba樂se幕dSc碧he礦me佩s:a博tr嶺an匹sa開ct內io爪n電wa嫌it之s壺fo鞠r蘭a癢lo猾ck渾o岔nl矮y六fo蘭ra肚sp倘ec欲if駱ie聯(lián)d畜am旁ou笛nt羅o羞f若ti駛me.羊Af漁te彈r座th城at凝,癥th曲e盲wa蜓it卵t饒im產es索o樣ut辣a軟nd燦t經he宣t紀ra賞ns遙ac但ti潛on燃i涼s概ro傻ll鉗ed殃b流ac探k.th她us母d蒼ea乖dl獵oc斤ks鴨a救re蹈n干ot挎p主os刪si蓄bl雄esi定mp商le軋t肝o殖im意pl跡em娃en有t;債b競ut牢s參ta華rv侵at爪io茫n杜is煤p句os擔si外bl摩e.搶A薦ls撤o福di裕ff身ic鹿ul疫t房誠to慢d忙et蔑er隊mi沈ne螞g匆oo駐d密va藍lu筐e也of滋t男he息t例im密eo膛ut陵i仆nt夠er內va俯l.Mo傾re惱D指ea娛dl料oc喬k拉Pr現(xiàn)ev嗓en云ti你onSt震ra仆te旋gi瞧es(續(xù))3.由2死鎖玩預防De州ad敬lo西ck郊D娛et足ec脖ti舟on等待未圖：De蹦ad侮lo膜ck蕩sca誰n是be旋d狼es蛙cr炸ib先ed掀a碑s賓awa識it銅-f藥orgr中ap專h,wh排ic誤h鏟co唯ns槐is敘ts筋o票f良a陸pa寇irG=臘(V,E),he奏reVis西a違s多et游o口f倒ve形rt窄ic課es鹽(指al碧l越th腿e微tr倡an生sa膊ct潔io緩ns于i基n熄th賠e令sy王st完em煌)Eis園a在s妙et梨o跳f籌ed患ge籠s;材e之ac庸h賓el載em淘en農t刊is刷a亦n華or突de返re巾d找pa疲irTiTj.等待虎圖的簡形成木與更士新：IfTiTjis扭i斃nE,腸th燈en沖t者he掠re溜i參s逆a駁di促re冶ct背ed紅e彎dg養(yǎng)e婆fr噴omTitoTj,回im師pl最yi密ng泄t烈ha許tTiis劃w智ai蜂ti謊ng寨f享orTjto模r出el鑄ea額se捏a猴d驗at勵a步it基em腳.Wh翼enTire像qu肥es曉ts我a毯d冬at廈a繞it褲em愚c煌ur脖re航nt涂ly鄰b泊ei巡壽ng庸h尖el澡d表byTj,惰th作en崗t答he伙e善dg妨eTiTjis飼i華ns冤er父te誤d霸in寒t拾he悔w副ai猜t-最fo推r厚gr抄ap腿h.拍T完hi團s恩ed挨ge綢i摘s癥re棒mo小ve般d盛on勺ly臨w造he激nTjis州n偶o伐lo蚊ng修er辛h球ol雞di蒜ng騎a塔d尋at振a歡it管em銀n堅ee鄰de綿d儲byTi.死鎖姿檢測撐方法醋：Th百esy扮st條em叼i漿s援in方a毅d褲ea桐dl查oc你k悅st稿at憤eif岔a賢nd衫o懸nl愁y色ifth歌e梁wa絲式it膠-f剛or細g姑ra喂ph呼h荷as床a果c揪yc棚le景.象M蛾us萄t貼in茄vo災ke席a亦d領ea膨dl聽oc伴k-黑de窩te哭ct遲io戲n杜al纏go蛾ri靜th寶m回pe動ri弊od燥ic灘al類ly較t射o洽lo脈ok商f縣orcy具cl郊es未.等待撐圖示例3.止3死鎖哥檢測3-循4如何禮檢測糞是否肚存在移死鎖痕？De簡ad她lo院ckDe珠te免ct多io泄n-等待倡圖例駛子Wa玩it配-f惕or乘g量ra握ph墊w戰(zhàn)it沈ho俘ut須acy喂cl龍e不存之在死除鎖Wa酬it放-f怕or傻g磨ra反ph由w求it競h店acy右cl忌e存在冷死鎖解釋垃：3-剪6下兩卵等待伴圖存姜在死帆鎖？3.龜3死鎖王檢測De漆ad轉lo壯ck動R您ec窗ov濟er范yWh留ende鞏ad曠lo仰ck掠i堂s年d笑et怕ec俘te籠d腸:So濃me返t競ra廉ns涼ac咽ti柳on帶w帶il舍l秘ha朱ve獅t感o專ro柱ll柜ed吊b儀ac棄k辟(m居ad縮慧e播a掌vi萄ct呼im斥)浪to受b總re毫ak午d伶ea減dl耍oc區(qū)k.寺Se謠le原ct莖t瘡ha某t巷tr曲an壯sa幣ct端io起n栗asvict塵im犧牲領品th太at糕w請il逐l煤in惱cu繞rmi濃ni緊mu攪mco擊st(選擇者事務掀回卷涼的代螺價最仁小者).Ro憶ll籮ba變ck仙-筆-延de桶te硬rm妄in鄙e及ho窗w乒fa希r員to律r爐ol岸l艱ba程ck府t普ra孝ns咐ac事ti任on回卷醋整個制事務走：To抹ta葵lro復ll害ba已ck:傲Ab辱or擁t暈th雀e免tr皂an乓sa元ct盤io小n播an唉d鈴th互en侮r酷es畜ta跳rt聰i村t.回卷悟事務曾的部茫分操春作：Mo嚇reef佛fe鄉(xiāng)豐ct蜓iv榮e核to細r可ol碼l框ba熔ck葡t駱ra否ns尤ac需ti雄on間o輛nl葵y手as潛f斬ar猶a順s樂ne綁ce寄ss培ar寫y促to熊b攔re顫akde悶ad攝lo器ck.(這種腳情形盤要求詢記錄微運行彩事務站的相循關狀再態(tài)信更息)St答ar端va愉ti售on活鎖ha控pp遣en映s揚if蠢s扛am舉e俊tr愧an武sa守ct共io罷n注is紹a教lw閘ay誤s景ch口os錯en瞧a案s臥vi現(xiàn)ct胡im亂.(解決任方法)Bu倦t紙we捎c放an身i建nc休lu掉deth散e椒nu業(yè)mb衣er末o禽f霸ro川ll互ba償ck弦s獎in軟t蠅he姨c隙os丘t霸fa倆ct燥or屬t微o造av彩oi招d靜st妙ar濕va聲ti紋on3-區(qū)7存在逮死鎖辜時如爐何解猜除？3.兇3死鎖芒檢測Ti備me撒st地am兩p-劃Ba猴se店d嶺Pr螺ot壇oc川ol賀sEa魯ch稿t防ra吳ns毯ac漂ti全on便i丹s呢is叛su絲式ed聲ati飾me識st戒am即pwh吐en骨i慕t傲en占te唐rs基t呢he電s喘ys者te氣m.下I愿f停an銀o構ld壇t么ra囑ns蜻ac而ti循onTiha物s圣ti芳me盞-s且ta冠mp扛T廚S(Ti),昏a籌n磚ew中t黎ra央ns鍛ac鋒ti笛onTjis帳a偽ss指ig晚ne閥d籌ti率me炕-s拖ta挑mp棒T碎S(Tj)房誠su薦ch裹t茫ha暫t愉TS奇(Ti)睡<T哈S(Tj).(利用范統(tǒng)一捧的系佛統(tǒng)時召間)Th葡e擁pr幸ot軌oc肌ol家m挎an迷ag撞es息c秤on括cu欲rr排en任t輝ex送ec負ut駛io替n絹su欄ch擔t悅ha北t飛th色e慣ti微me意-s甚ta攝mp帖sde凈te春rm顏in壤eth夾e桑se近ri痛al球iz獲ab熔il托it撲y格or雕de史r.In很o摔rd修er段t帳o所as羽su冷re稠s范uc緞h繁be境ha稍vi窄or礙,肉th推e伏pr友ot欺oc金ol欺m雨ai剖nt窮ai動ns晴f漂orea沫chda芽taQtw剝oti瞧me儲st賤am前p拾va作lu哲es隱:W-宏ti腹me庸st活am怕p(Q)迎is說t利hela慌rg花es欠tti磁me需-s鴿ta價mp柔o掉f鹽an關y錦tr鹽an炭sa戀ct邁io達n陡th撈at強e構xe標cu怒te絞dwr殼it博e(Q)濫su構cc勉es搶sf日ul懷ly度.R-狐ti屈me指st仗am近p(Q)厚is弄t養(yǎng)hela翅rg她es針tti宗me叨-s役ta附mp狠o徹f茫an分y捕tr領an戀sa袋ct喝io進n管th較at賞e俯xe棟cu嘉te臣dre付ad(Q)切su亮cc屠es勤sf房誠ul看ly干.四?；诶褧r間潮戳的遼協(xié)議4-亡1什么席是時結間戳撲協(xié)議獨？4.嘉1數據羊項的抹時間墾戳Ti炎me丈st瀉am坦p-喂Ba駛se沒d卻Pr菊ot弱oc翻ol句s-規(guī)則芝說明Th征e侮ti旨me命st薪am科p蟻or申de踏ri烈ng局p腦ro索to滅co刻len譽su頑re尤sth給at伴a康ny比c子on執(zhí)fl扒ic它ti門ngre重adan頁dwr乓it房誠eop云er貧at驕io喜ns插a膨re仇e裁xe患cu洗te訂d時in福t舟im珍es接ta駝mp姓o鈴rd率er牲.協(xié)議動規(guī)則哀說明顏：讀數胡據的艱處理:灣Su膨pp瀉os塵ea拐tr滴an妙sa腳ct物io董n汪Tiis蔬su銹es屋are育ad(Q)1）IfTS殲(Ti)W-t秤im敵es該ta態(tài)mp紀(Q),途t幕he蘋nTine化ed慌s棒to應r尚ea宏d羅a此va河lu托e鉛ofQth春at繳w校asal差re捷ad肝yov始er漢wr疑it堂te超n.老事蘇務Ti讀到熊新事迷務寫字的數昨據-異常He碰nc城e,符th咐ere菌adop唐er燒at刻io討n桐isre慢je極ct炮ed,擴an劃dTiis貞r害ol衰le忠dba梯ck撕.2）IfTS嘗(Ti)W-t兆im倒es狡ta餡mp喬(Q),活t敏he揉n崖th碎ere遼adop惹er羞at冒io部n漲is損e躬xe勁cu扁te刪d,an丈dR-提t(yī)i惑me滴st西am否p(Q)isse齡t西toma臨x(R便-t叔im站es艙ta冷mp險(Q),TS墻(Ti))假.新事炎務Ti讀老器事務鬧寫的抱數據-O脊K寫數義據的處尸理:直觀秀例示杜（例子）4-超2時間鄰戳協(xié)稀議為蠢何能捷保持鹿可串葡行化確？4.右2時間仿戳協(xié)及議規(guī)柳則Ti敲me拒st嗎am答p-柿Ba李se黑d檔Pr絮ot聽oc伍ol翁s-規(guī)則幻玉說明(續(xù))寫數加據的烤處理淡：Su也pp勻os蘿eth妖at瓣t糠ra發(fā)ns贈ac質ti誤onTiis育su橫eswr茅it則e(Q).1）IfTS妹(Ti)包<R-t美im搜es席ta義mp符(Q),滔t笛he座n曾th驢e諷va侮lu犧e輩ofQth認atTiis匆p悄ro笛du執(zhí)ci壩ng光w版as無n竿ee啟de扛d蜜pr穴ev仰io鉛us任ly險,姻an撇d雞th箭e文sy屬st幅emas殘su大me反dth瓜atva脫lu銅ewo妖ul敬d倉ne裹ve具r訪bepr逗od天uc索ed蠟.新事突務未電能讀抵到老錫事務Ti寫的下數據-異常He歸nc瘡e,饒t嚼hewr押it倒eop姿er滅at古io闖n呼isre臉je抱ct苦ed,我an臟dTiis植r飽ol鄙le柿d鉤ba雨ck文.2）IfTS使(Ti)規(guī)<W-t從im沾es芳ta殃mp怠(Q),離t胳he堵nTiis呈a制tt坦em每pt烘in蜓g永to莖w箱ri圈te期a案nob校so藥le銳te已過撫時的va騙lu蔑eofQ.若老皇事務Ti再次礙讀自錫己所雄寫Q,必誤很讀-異常He結nc胸e,外t泡hi牛swr緩it伴eop鉗er位at銹io嘩n帖isre嗽je滋ct補ed,斜an蔽dTiis抽r左ol唱le廚d扣ba仰ck竄.3)驚Ot困he尊rw島is訴e,把th某ewr佳it被eop暖er蝴at室io懷n催is祖e勤xe訪cu違te悲d,瓶a慎nd卻W使-t糕im詠es爸ta茅mp饒(Q)is氧s賭et蹲t功oTS摟(Ti).新事垮務Ti在老蒜事務塊讀寫助后進乖