課程設(shè)計(jì)-銀行家算法的設(shè)計(jì)與實(shí)現(xiàn)

1、內(nèi)蒙古工業(yè)大學(xué)操作系統(tǒng)課程設(shè)計(jì)學(xué)校代碼： 10128學(xué) 號： 200810205004課程設(shè)計(jì)題 目：銀行家算法的設(shè)計(jì)與實(shí)現(xiàn) 學(xué)生姓名：朱見濤 學(xué) 院：信息工程學(xué)院系 別：計(jì)算機(jī)系 專 業(yè)：軟件工程 班 級：軟08-1指導(dǎo)教師：秦俊平 講師馬志強(qiáng) 講師20011年1月18日 18內(nèi)蒙古工業(yè)大學(xué)課程設(shè)計(jì)任務(wù)書（二）學(xué)院（系）：信息學(xué)院計(jì)算機(jī)系 課程名稱：操作系統(tǒng)課程設(shè)計(jì) 指導(dǎo)教師（簽名）： 專業(yè)班級： 軟件工程 081 學(xué)生姓名： 朱見濤 學(xué)號： 200810205004 一、課程設(shè)計(jì)題目銀行家算法的設(shè)計(jì)與實(shí)現(xiàn)二、課程設(shè)計(jì)的目的通過銀行家算法設(shè)計(jì)與實(shí)現(xiàn)，可以加深學(xué)生對死鎖的理解，掌握死鎖的預(yù)防、

2、避免、檢測和解除的基本原理，重點(diǎn)掌握死鎖的避免方法銀行家算法。使學(xué)生初步具有研究、設(shè)計(jì)、編制和調(diào)試操作系統(tǒng)模塊的能力。 三、課程設(shè)計(jì)的主要內(nèi)容和要求（包括原始數(shù)據(jù)、技術(shù)參數(shù)、設(shè)計(jì)要求、工作量要求等） 技術(shù)參數(shù)： windows xp系統(tǒng)，vc+6.0開發(fā)工具。設(shè)計(jì)要求： 1 設(shè)計(jì)銀行家算法的核心數(shù)據(jù)結(jié)構(gòu)、安全性檢查算法；2 畫出銀行家算法流程圖；3 編程實(shí)現(xiàn)算法功能；4 編寫課程設(shè)計(jì)說明書。 工作量要求：完成以上設(shè)計(jì)要求中的所有算法功能。四、工作進(jìn)度安排 周一：布置、講解題目，收集資料；周二：系統(tǒng)分析，算法設(shè)計(jì)；周三：編制、調(diào)試程序；周四：測試系統(tǒng)，形成設(shè)計(jì)結(jié)論，編寫課設(shè)報(bào)告；周五：系統(tǒng)及材料

3、驗(yàn)收，課設(shè)答辯。五、主要參考文獻(xiàn)1 張堯?qū)W編計(jì)算機(jī)操作系統(tǒng)教程（第三版）習(xí)題解答與實(shí)驗(yàn)指導(dǎo)北京:清華大學(xué)出版社，20062 湯子瀛主編計(jì)算機(jī)操作系統(tǒng)（第三版）西安:西安電子科技大學(xué)出版社，2001 3 張坤等編操作系統(tǒng)實(shí)驗(yàn)教程北京:清華大學(xué)出版社，2008審核批準(zhǔn)意見系（教研室）主任（簽字） 目 錄第一章設(shè)計(jì)內(nèi)容111 設(shè)計(jì)目的112 設(shè)計(jì)要求113 程序設(shè)計(jì)思想1第二章 數(shù)據(jù)結(jié)構(gòu)、算法和算法流程圖221 數(shù)據(jù)結(jié)構(gòu)222 程序功能圖223 程序流程圖3第三章 程序運(yùn)行結(jié)果及分析631 程序運(yùn)行結(jié)果632 程序分析7第四章 心得體會8參考文獻(xiàn)9附錄 程序清單10第一章 設(shè)計(jì)內(nèi)容11 設(shè)計(jì)目的通過

4、銀行家算法設(shè)計(jì)與實(shí)現(xiàn)，可以加深學(xué)生對死鎖的理解，掌握死鎖的預(yù)防、避免、檢測和解除的基本原理，重點(diǎn)掌握死鎖的避免方法銀行家算法。使學(xué)生初步具有研究、設(shè)計(jì)、編制和調(diào)試操作系統(tǒng)模塊的能力。12 設(shè)計(jì)要求1.問題描述銀行家算法是一種最有代表性的避免死鎖的算法。在避免死鎖方法中允許進(jìn)程動態(tài)的申請資源，但系統(tǒng)在進(jìn)行資源分配之前，應(yīng)先計(jì)算此次分配資源的安全性，若分配不會導(dǎo)致系統(tǒng)進(jìn)入不安全狀態(tài)，則分配，否則等待。要解釋銀行家算法，必須先解釋操作系統(tǒng)安全狀態(tài)和不安全狀態(tài)。安全序列是指一個(gè)進(jìn)程序列p1，pn是安全的，如果對于每一個(gè)進(jìn)程pi(1in），它以后尚需要的資源量不超過系統(tǒng)當(dāng)前剩余資源量與所有進(jìn)程pj (j

5、 i )當(dāng)前占有資源量之和。安全狀態(tài)：如果存在一個(gè)由系統(tǒng)中所有進(jìn)程構(gòu)成的安全序列p1，pn，則系統(tǒng)處于安全狀態(tài)。安全狀態(tài)一定是沒有死鎖發(fā)生。不安全狀態(tài)：不存在一個(gè)安全序列。不安全狀態(tài)不一定導(dǎo)致死鎖。我們可以把操作系統(tǒng)看作是銀行家，操作系統(tǒng)管理的資源相當(dāng)于銀行家管理的資金，進(jìn)程向操作系統(tǒng)請求分配資源相當(dāng)與用戶向銀行家貸款。操作系統(tǒng)按照銀行家指定的規(guī)則為進(jìn)程分配資源，當(dāng)進(jìn)程首次申請資源時(shí)，要測試該進(jìn)程對資源的最大需求量，如果系統(tǒng)現(xiàn)存的資源可以滿足他的最大需求量則按當(dāng)前的申請量分配資源，否則就推遲分配。當(dāng)進(jìn)程在執(zhí)行中繼續(xù)申請資源時(shí)，先測試該進(jìn)程已占用的資源數(shù)與本次申請的資源數(shù)之和是否超過了該進(jìn)程對資

6、源的最大需求量。若超過則拒絕分配資源，若沒有超過則再測試系統(tǒng)現(xiàn)存的資源能否滿足該進(jìn)程尚需的最大資源量，若能滿足則按當(dāng)前的申請量分配資源，否則也要推遲分配。2.基本要求1）分析設(shè)計(jì)內(nèi)容，給出解決方案（要說明設(shè)計(jì)實(shí)現(xiàn)的原理，采用的數(shù)據(jù)結(jié)構(gòu)）。2）畫出程序的基本結(jié)構(gòu)框圖和流程圖。3）對程序的每一部分要有詳細(xì)的設(shè)計(jì)分析說明。4）源代碼格式要規(guī)范。5）設(shè)計(jì)合適的測試用例，隊(duì)得到的運(yùn)行結(jié)果要有分析。6）設(shè)計(jì)中遇到的問題，設(shè)計(jì)的心得體會。7）按期提交完整的程序代碼，可執(zhí)行程序和課程設(shè)計(jì)報(bào)告。1.3 程序設(shè)計(jì)思想1.設(shè)計(jì)思想輸入當(dāng)前進(jìn)程資源的使用情況以及整個(gè)系統(tǒng)的資源使用情況，并進(jìn)行初始化安全性檢查；如果是不

7、安全狀態(tài)，重新初始化系統(tǒng)；否則，從等待隊(duì)列中提取一個(gè)等待進(jìn)程，使用銀行家算法進(jìn)行檢測，輸出當(dāng)前系統(tǒng)的狀態(tài)和安全序列；如果是安全狀態(tài)，系統(tǒng)繼續(xù)從等待隊(duì)列中提取等待進(jìn)程進(jìn)行檢查；如果是不安全狀態(tài)，進(jìn)程回到等待隊(duì)列，系統(tǒng)從等待隊(duì)列中提取等待進(jìn)程進(jìn)行檢查。系統(tǒng)中申請資源的進(jìn)程全部進(jìn)入等待隊(duì)列等候處理。第二章 數(shù)據(jù)結(jié)構(gòu)、算法和算法流程圖21 數(shù)據(jù)結(jié)構(gòu)銀行家算法中用到的主要數(shù)據(jù)結(jié)構(gòu)可用資源向量 int availablei /j為資源的種類最大需求矩陣 int maxij /i為進(jìn)城的數(shù)量分配矩陣 int allocationij 需求矩陣 int needij=maxij-allocationij申請各

8、類資源數(shù)量 int requestij /i申請j資源的數(shù)量工作向量 int worki int finishi安全序列 int pi22 程序功能圖銀行家算法系統(tǒng)顯示分配資源狀態(tài)資源分配安全性檢查初始化資源銀行家算法實(shí)現(xiàn)資源分配顯示安全序列圖2.1文件系統(tǒng)提供的文件操作有建立文件(mkfile)、復(fù)制文件(copy)、顯示文件所有內(nèi)容(type)、刪除文件(delfile)?？梢酝ㄟ^鍵盤輸入命令來模擬文件的操作。23 程序流程圖（1）主程序流程圖：圖2.1第三章 程序運(yùn)行結(jié)果及分析31 程序運(yùn)行結(jié)果（1）初始化界面圖3.1（2）檢測系統(tǒng)資源分配是否安全（若安全，輸入安全序列）圖3.2圖3.3

9、32 程序分析本程序依靠鍵盤輸入初始化系統(tǒng)資源數(shù)量及種類，有銀行家算法檢驗(yàn)系統(tǒng)資源是否安全，輸出安全序列。提出請求requesti，同意分配，則進(jìn)行安全性算法safe（），否則輸出提示：請求被拒絕。直到所有進(jìn)程finish=true，安全且輸出安全序列，安全算法safe（）結(jié)束。第四章 心得體會通過本次的課程設(shè)計(jì)，使我能夠正確運(yùn)用操作系統(tǒng)課程中所學(xué)的基本理論和知識。操作系統(tǒng)的基本特征是并發(fā)與共享。系統(tǒng)允許多個(gè)進(jìn)程并發(fā)執(zhí)行，并且共享系統(tǒng)的軟、硬件資源。為了最大限度的利用計(jì)算機(jī)系統(tǒng)的資源，操作系統(tǒng)應(yīng)采用動態(tài)分配的策略，但是這樣就容易因資源不足，分配不當(dāng)而引起“死鎖”。而我本次課程設(shè)計(jì)就是得用銀行家

10、算法來避免“死鎖”。銀行家算法是一個(gè)分配資源的過程，是分配的序列不會產(chǎn)生死鎖。此算法的中心思想是：按該法分配資源時(shí)，每次分配后總存在著一個(gè)進(jìn)程，如果讓它單獨(dú)運(yùn)行下去，必然可以獲得它所需要的全部資源，也就是說，它能結(jié)束，而它結(jié)束后可以歸還這類資源以滿足其他申請者的需要。本次程序就是按照上面的思路展開的。但是因?yàn)闀r(shí)間上的倉促，本課程設(shè)計(jì)存在以下不足：一、不能實(shí)現(xiàn)并發(fā)操作，即當(dāng)總資源同時(shí)滿足幾個(gè)進(jìn)程所需要的資源數(shù)時(shí)，這些進(jìn)程不能同時(shí)進(jìn)行，只能一一按進(jìn)程順序執(zhí)行。二、掃描進(jìn)程順序單一，只能按進(jìn)程到來的順序來掃描，從而產(chǎn)生的安全序列只能是在這個(gè)順序的基礎(chǔ)上產(chǎn)生的，而其實(shí)安全序列是有多個(gè)的。三、對進(jìn)程數(shù)和

11、資源數(shù)進(jìn)行的數(shù)量進(jìn)行了限制，都只能最多有十個(gè)。四、運(yùn)行程序后，界面較差，進(jìn)程數(shù)，所需要資源數(shù)，已分配資源數(shù)，能用資源數(shù)，不能一目了然。設(shè)計(jì)一個(gè)軟件，先要做好需求分析，這一點(diǎn)很重要，如果沒有分析好需求，到軟件設(shè)計(jì)的最后，發(fā)現(xiàn)所做的功能不符合要求，那么一切都得重做。還有比較重要的是，畫好程流程圖。在編程和調(diào)試的過程中，經(jīng)常會出現(xiàn)意想不到的問題，并非每個(gè)問題都可以從相關(guān)資料中找到解決方法，有些問題是無法預(yù)料到的，這就需要通過自己理性的分析得出問題的解決方案。在設(shè)計(jì)過程中，查詢了不少相關(guān)資料，不斷的發(fā)現(xiàn)問題、提出問題、解決問題。總的來說通過這次的設(shè)計(jì)的學(xué)習(xí)使我學(xué)到了很多在平時(shí)的學(xué)習(xí)中學(xué)不到的很多東西，

12、通過這次課程設(shè)計(jì)，使我學(xué)到了很多的實(shí)用性知識。除了更深的了解這個(gè)算法，而且對c語言進(jìn)行了復(fù)習(xí)，而且其過程中有很多的知識點(diǎn)都不記得了，所以在此感謝在此過程中幫助過我的老師和同學(xué)。參考文獻(xiàn)1 張堯?qū)W編計(jì)算機(jī)操作系統(tǒng)教程（第三版）習(xí)題解答與實(shí)驗(yàn)指導(dǎo)北京:清華大學(xué)出版社，20062 湯子瀛主編計(jì)算機(jī)操作系統(tǒng)（第三版）西安:西安電子科技大學(xué)出版社，2001 3 csdn論壇4 張麗芬等編操作系統(tǒng)實(shí)驗(yàn)教程北京:清華大學(xué)出版社，2006附錄 程序清單#include using namespace std;#define maxprocess 10 /*最大進(jìn)程數(shù)*/#define maxresource

13、10 /*最大資源數(shù)*/int availablemaxresource; /*可用資源數(shù)組*/int maxmaxprocessmaxresource; /*最大需求矩陣*/int allocationmaxprocessmaxresource; /*分配矩陣*/int needmaxprocessmaxresource; /*需求矩陣*/int requestmaxprocessmaxresource; /*進(jìn)程申請資源數(shù)*/bool finishmaxprocess; /*系統(tǒng)是否有足夠的資源分配*/int pmaxprocess; /*記錄序列*/int m,n; /*m個(gè)進(jìn)程,n個(gè)資

14、源*/void init();bool safe();void bank();int main() init(); safe(); bank();void init() /*初始化算法*/ int i,j; printf(請輸入進(jìn)程的數(shù)目:); scanf(%d,&m); printf(請輸入資源的種類:); scanf(%d,&n); printf(請輸入每個(gè)進(jìn)程最多所需的各資源數(shù),按照%dx%d矩陣輸入n,m,n); for(i=0;im;i+) for(j=0;jn;j+) scanf(%d,&maxij); printf(請輸入每個(gè)進(jìn)程已分配的各資源數(shù),也按照%dx%d矩陣輸入n,m,

15、n); for(i=0;im;i+) for(j=0;jn;j+) scanf(%d,&allocationij); needij=maxij-allocationij; if(needij0) printf(您輸入的第%d個(gè)進(jìn)程所擁有的第%d個(gè)資源數(shù)錯(cuò)誤,請重新輸入:n,i+1,j+1); j-; continue; printf(請輸入各個(gè)資源現(xiàn)有的數(shù)目:n); for(i=0;in;i+) scanf(%d,&availablei); void bank() /*銀行家算法*/ int i,cusneed; char again; while(1) printf(請輸入要申請資源的進(jìn)程號

16、(注:第1個(gè)進(jìn)程號為0,依次類推)n); scanf(%d,&cusneed); printf(請輸入進(jìn)程所請求的各資源的數(shù)量n); for(i=0;in;i+) scanf(%d,&requestcusneedi); for(i=0;ineedcusneedi) printf(您輸入的請求數(shù)超過進(jìn)程的需求量!請重新輸入!n); continue; if(requestcusneediavailablei) printf(您輸入的請求數(shù)超過系統(tǒng)有的資源數(shù)!請重新輸入!n); continue; for(i=0;in;i+) availablei-=requestcusneedi; alloca

17、tioncusneedi+=requestcusneedi; needcusneedi-=requestcusneedi; if(safe() printf(同意分配請求!n); else printf(您的請求被拒絕!n); for(i=0;in;i+) availablei+=requestcusneedi; allocationcusneedi-=requestcusneedi; needcusneedi+=requestcusneedi; for(i=0;im;i+) finishi=false; printf(您還想再次請求分配嗎?是請按y/y,否請按其它鍵n); scanf(%d,

18、&again); if(again=y|again=y) continue; break; bool safe() /*安全性算法*/ int i,j,k,l=0; int workmaxresource; /*工作數(shù)組*/ for(i=0;in;i+) worki=availablei; for(i=0;im;i+) finishi=false; for(i=0;im;i+) if(finishi=true) continue; else for(j=0;jworkj) break; if(j=n) finishi=true; for(k=0;kn;k+) workk+=allocation

19、ik; pl+=i; i=-1; else continue; if(l=m) printf(系統(tǒng)是安全的n); printf(安全序列:n); for(i=0;i); printf(n); return true; printf(系統(tǒng)是不安全的n); return false; g an employment tribunal claiemployment tribunals sort out disagreements between employers and employees.you may need to make a claim to an employment tribunal

20、 if: you dont agree with the disciplinary action your employer has taken against you your employer dismisses you and you think that you have been dismissed unfairly.for more information about dismissal and unfair dismissal, seedismissal.you can make a claim to an employment tribunal, even if you hav

21、entappealedagainst the disciplinary action your employer has taken against you. however, if you win your case, the tribunal may reduce any compensation awarded to you as a result of your failure to appeal.remember that in most cases you must make an application to an employment tribunal within three

22、 months of the date when the event you are complaining about happened. if your application is received after this time limit, the tribunal will not usually accept i.if you are worried about how the time limits apply to you, take advice from one of the organisations listed underfurther help.employmen

23、t tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation.most people find making a claim to an employment tribunal challenging. if you are thinking about making a claim to an employment tribunal, you should ge

24、t help straight away from one of the organisations listed underfurther help.if you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your compensation if you win the case. this is known as adamages-based agreement. in england a

25、nd wales, your solicitor cant charge you more than 35% of your compensation if you win the case.if you are thinking about signing up for a damages-based agreement, you should make sure youre clear about the terms of the agreement. it might be best to get advice from an experienced adviser, for examp

26、le, at a citizens advice bureau. to find your nearest cab, including those that give advice by e-mail, click onnearest cab.for more information about making a claim to an employment tribunal, seeemployment tribunals.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-

27、racism taskforce, is in london for the football associations 150th anniversary celebrations and will attend citys premier league match at chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to s

28、peak to him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.c

29、ska said they were surprised and disappointed by toures complaint. in a statement the russian side added: we found no racist insults from fans of cska.age has reached the end of the beginning of a word. may be guilty in his seems to passing a lot of different life became the appearance of the same d

30、ay; may be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. always feel oneself should go to do something, or write something. twenty years of life trajectory deeply shallow, suddenly feel something, do it.一字開頭的年齡

31、已經(jīng)到了尾聲。或許是愧疚于自己似乎把轉(zhuǎn)瞬即逝的很多個(gè)不同的日子過成了同一天的樣子；或許是追溯過去，對自己那些近乎偏執(zhí)的怪異信念的醒悟，這些天以來，思緒一直很凌亂，在腦海中不斷糾纏?？傆X得自己自己似乎應(yīng)該去做點(diǎn)什么，或者寫點(diǎn)什么。二十年的人生軌跡深深淺淺，突然就感覺到有些事情，非做不可了。the end of our life, and can meet many things really do?而窮盡我們的一生，又能遇到多少事情是真正地非做不可？during my childhood, think lucky money and new clothes are necessary for n

32、ew year, but as the advance of the age, will be more and more found that those things are optional; junior high school, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isnt really grow up, it seems i

33、s not so important; then in high school, think dont want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown

34、 a basketball hoops, suddenly found himself has already cant remember his appearance.童年時(shí)，覺得壓歲錢和新衣服是過年必備，但是隨著年齡的推進(jìn)，會越來越發(fā)現(xiàn)，那些東西根本就可有可無；初中時(shí)，以為要有一場暗戀才意味著真正的成長，但三年過去后，自己心平氣和的寫同學(xué)錄的時(shí)候，突然就發(fā)現(xiàn)是不是真正的成長了，好像并沒有那么重要了；然后到了高中，覺得非要吐露出自己的心聲才能為高中生涯里的懵懂情愫劃上一個(gè)句點(diǎn)，但畢業(yè)晚會的時(shí)候最終還是被梗塞在了咽喉，后來再次站在他曾經(jīng)揮汗如雨的球場，看著他投過籃球的球框時(shí)，突然間發(fā)現(xiàn)自己已經(jīng)

35、想不起他的容顏。originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time.原來，這個(gè)世界上，對某個(gè)事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅(jiān)決，還有，時(shí)間。a persons time, your ideas are always special to clear. want, want, line is clear, as if nothing could shake his. also once seemed to be

36、 determined to do something, but more often is he backed out at last. dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. those who do, just green years oneself give oneself an arm injection, or is a self-righteous spiritua

37、l.一個(gè)人的時(shí)候，自己的想法總是特別地清晰。想要的，不想要的，界限明確，好像沒有什么可以撼動自己。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時(shí)候是最后又打起了退堂鼓。嫌惡過自己的怯懦，最終卻發(fā)現(xiàn)有很多緣分，有很多錯(cuò)過，好像冥冥之中真的已經(jīng)注定。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說，是自以為是的精神寄托罷了。at the moment, the sky is dark, the air is fresh factor after just rained. suddenly thought of blue plaid shirt; those were bro

38、ken into various shapes of stationery; from the corner at the beginning of deep friendship; have declared the end of the encounter that havent start planning. those years, those days of do, finally, like youth, will end in our life.此刻，天空是陰暗的，空氣里有著剛下過雨之后的清新因子。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還

39、有那場還沒有開始就宣告了終結(jié)的邂逅計(jì)劃那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。baumgartner the disappointing news: mission aborted. r plays an important role in this mission. starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon,

40、with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the supersonic descent could happen as early as sunda.the weathethe balloon will slowly drift to the edge of space at 120,000