计算机考研真题操作系统部分.doc

romoting the construction of rule of law, but also the most basic development environment. Despite my good social order in General, but there are law-abiding consciousness, social order is not standard, regardless of faith, Twining visit visit and other outstanding problems. We want to actively promote the field of multi-level governance according to law, promote the continuous improvement of the social environment. To promote universal compliance. Actively foster the rule of law culture, carry out law publicity and education on honesty and trustworthiness, guide the masses and consciously abide by the law, failing to find method, problem-solving method, method of gradually changing the world, he is not looking for but someone unspoken rules, formed all law law, abide by the good atmosphere. To strengthen the comprehensive management of public security. Deepening peace xingan construction, strongly against violence crime, mafia and serious criminal offences, to protect the legitimate rights and interests of citizens, legal persons, carry out criminal policy of temper justice with mercy, the maximum stimulating social vitality, and earnestly safeguard social harmony and stability. To resolve social conflicts by law. To further smooth channels of reporting social conditions and public opinion, improving regulation, arbitration, as wellrelationship between Government and business. The two sessions, General Secretary of Pro, clear the word succinctly summarized the new relationship between Government and business, as pure politics, reshaping the political relationship specified in the direction. District leaders in handling political and business relations, engage in trading power for money, and finally stumbled, we a lesson, always keep in mind that Pro, clean practicing Pro, clear. Pro is to open a sincere engagement with private enterprise to help solve practical difficulties; Clear is to clarify the Division of power, exercised in accordance with, private entrepreneurs with innocent purity, not abusing power for personal gain, not to engage in trading power for money. Third, in order to maintain fairness and justice. Fairness and justice is the lifeline of the rule of law, is the best development environment. Currently, lax law enforcement and the judicial sector in our region also exist to varying degrees, law enforcement departments and individual window units power for personal gains and bribes, thick friends, relations, human cases, money cases in which seriously infringe on the legitimate rights and interests of enterprises and people. Especially some law enforcement and inspection for profit purposes, deliberately looking for corporate loopholes, found directly under the ticket does not give business improvement opportunities. We recruit a company doesnt easily, cultivating a business more difficult, never for personal gain, systematic harassment, card, last checked to check to get the enterprise collapsed. To guarantee the legitimate rights and interests. Always proceed from the overall situation of reform and development of services, fully consider the characteristics of production and management in non-public enterprises and social benefits, an accurate grasp of legal limits, protect the enthusiasm of entrepreneurs and practitioners in innovation and entrepreneurship, enhancing expectations and confidence. To promote strict enforcement. Strengthening law enforcement procedures, improve law enforcement performance evaluation, strengthening the supervision of law enforcement, exploration and practice of risk control mechanism of law enforcement to further standardize the social security, urban management, road traffic administrative law enforcement, effectively free, extensive law-enforcement and lax enforcement of law enforcement and other issues. To uphold justice. Justice is the last line of Defense to safeguard fairness and justice, to unequivocally support the courts and procuratorates independently exercise level . Judicial activities were rampant, must not be allowed to run, favors, money, must not be allowed to knowingly violate the miscarriage, violations of the legitimate rights and interests of the masses must not be allowed to abuse of power, to make forest mass can be felt in every judicial cases in equity and justice. Four to deepen grass-roots governance according to lawchain do long, and put scale big. To serve the development of enterprises. Duocuo simultaneously improving service efficiency, build better public services platform, enhance work efficiency, initiative to help businesses solve the project procedures, financing loans, issues such as land-use approval, reduce operating costs, business travel light and enhance the confidence to overcome all kinds of difficulties and the Foundation, real entrepreneurial passion play entrepreneurship, enhance the internal vitality and creativity. SI XING an construction, promoting the rule of law, tries to make the transformation of forest development XI General Secretary stressed, to reinvigorate Northeast China, optimized development environment is very important. Environment of rule of law most gather Moss, the most conducive to development. Improving the leading cadres using the method of thought and the rule of law Administration work, problem-solving, the ability to promote the development, is the key to promoting the rule of law. The law may affect the efficiency of out of the path of development will be more smooth, won development gains will be sustained, and end with greater efficiency. Leading cadres at all levels should take the lead in respect of law law, abide by, and actively foster Socialist culture, actively promoting the field of multi-level governance according to law, guide the masses and consciously abide by the law, failing to find law, solve the problem by law, in accordance with the law prevail. XXX administration by law of leading cadres do not exist on the rule of law, law enforcement, casual, and vow not to investors, the new scores and other turmoil. These important expositions on my district create good development environment with highly targeted and guidance, especially the General Secretary pointed out that the chaos in my area also exists to varying degrees, some even quite serious. Leading cadres at all levels must improve the development environment of rule of law as a fundamental task, adhere to the problem oriented, solid and solve the problems in the construction of rule of law, to rule the new effect for development environment improvements. To hold key minority. Leaders of this group, although few in number, but the effect is critical. If a local leaders take the lead right according to law, in accordance with the law, the local CPPCC fresh, pragmatic and efficient development environment. Conversely, if a local leaders of ignoring the law, impunity, not only the political environment will be destroyed, will have serious implications for the development environment. Now, some leading cadres lack of awareness on the importance of learning, that learn or not does not matter. Think efficiency is too low too much, act according to the procedure, than an executive order getting along with. In dealing with complex issues, often speak of settling and done; on the issue of handling letters and visits, like to spend money and buy stop and stable, but disregard the law administration, in accordance with the law, the rulechain do long, and put scale big. To serve the development of enterprises. Duocuo simultaneously improving service efficiency, build better public services platform, enhance work efficiency, initiative to help businesses solve the project procedures, financing loans, issues such as land-use approval, reduce operating costs, business travel light and enhance the confidence to overcome all kinds of difficulties and the Foundation, real entrepreneurial passion play entrepreneurship, enhance the internal vitality and creativity. SI XING an construction, promoting the rule of law, tries to make the transformation of forest development XI General Secretary stressed, to reinvigorate Northeast China, optimized development environment is very important. Environment of rule of law most gather Moss, the most conducive to development. Improving the leading cadres using the method of thought and the rule of law Administration work, problem-solving, the ability to promote the development, is the key to promoting the rule of law. The law may affect the efficiency of out of the path of development will be more smooth, won development gains will be sustained, and end with greater efficiency. Leading cadres at all levels should take the lead in respect of law law, abide by, and actively foster Socialist culture, actively promoting the field of multi-level governance according to law, guide the masses and consciously abide by the law, failing to find law, solve the problem by law, in accordance with the law prevail. XXX administration by law of leading cadres do not exist on the rule of law, law enforcement, casual, and vow not to investors, the new scores and other turmoil. These important expositions on my district create good development environment with highly targeted and guidance, especially the General Secretary pointed out that the chaos in my area also exists to varying degrees, some even quite serious. Leading cadres at all levels must improve the development environment of rule of law as a fundamental task, adhere to the problem oriented, solid and solve the problems in the construction of rule of law, to rule the new effect for development environment improvements. To hold key minority. Leaders of this group, although few in number, but the effect is critical. If a local leaders take the lead right according to law, in accordance with the law, the local CPPCC fresh, pragmatic and efficient development environment. Conversely, if a local leaders of ignoring the law, impunity, not only the political environment will be destroyed, will have serious implications for the development environment. Now, some leading cadres lack of awareness on the importance of learning, that learn or not does not matter. Think efficiency is too low too much, act according to the procedure, than an executive order getting along with. In dealing with complex issues, often speak of settling and done; on the issue of handling letters and visits, like to spend money and buy stop and stable, but disregard the law administration, in accordance with the law, the rule2015年硕士研究生入学考试：操作系统复习资料12014年计算机学科研究生入学统一考试计算机科学与技术学科联考计算机学科专业基础综合考试大纲. 考试性质计算机学科专业基础综合考试是为高等院校和科研院所招收计算机科学与技术学科的硕士研究生而设置的具有选拔性质的联考科目，其目的是科学、公平、有效地测试学生掌握计算机科学与技术学科大学本科阶段专业基础知识、基本理论、基本方法的水平和分析问题、解决问题的能力，评价的标准是高等院校计算机科学与技术学科优秀本科毕业生所能达到的及格或及格以上水平，以利于各高等院校和科研院所择优选拔，确保硕士研究生的招生质量。. 考查目标计算机学科专业基础综合考试涵盖数据结构、计算机组成原理、操作系统和计算机网络等学科专业基础课程。要求考生系统地掌握上述专业基础课程的基本概念、基本原理和基本方法，能够综合运用所学的基本原理和基本方法分析、判断和解决有关理论问题和实际问题。. 考试形式和试卷结构一、试卷满分及考试时间本试卷满分为150分，考试时间为180分钟二、答题方式答题方式为闭卷、笔试三、试卷内容结构数据结构45分计算机组成原理45分操作系统35分计算机网络25分四、试卷题型结构单项选择题80分（40小题，每小题2分）综合应用题70分. 考查内容操作系统【考查目标】1. 掌握操作系统的基本概念、基本原理和基本功能，理解操作系统的整体运行过程。2. 掌握操作系统进程、内存、文件和I/O管理的策略、算法、机制以及相互关系。3. 能够运用所学的操作系统原理、方法与技术分析问题和解决问题，并能利用C语言描述相关算法。一、操作系统概述（一）操作系统的概念、特征、功能和提供的服务（二）操作系统的发展与分类（三）操作系统的运行环境1. 内核态与用户态2. 中断、异常3. 系统调用（四）操作系统体系结构二、进程管理（一）进程与线程1. 进程概念2. 进程的状态与转换3. 进程控制4. 进程组织5. 进程通信共享存储系统，消息传递系统，管道通信。6. 线程概念与多线程模型（二）处理机调度1. 调度的基本概念2. 调度时机、切换与过程3. 调度的基本准则4. 调度方式5. 典型调度算法先来先服务调度算法，短作业（短进程、短线程）优先调度算法，时间片轮转调度算法，优先级调度算法，高响应比优先调度算法，多级反馈队列调度算法。（三）同步与互斥1. 进程同步的基本概念2. 实现临界区互斥的基本方法软件实现方法，硬件实现方法。3. 信号量4. 管程5. 经典同步问题生产者-消费者问题，读者-写者问题，哲学家进餐问题。（四）死锁1. 死锁概念2. 死锁处理策略3. 死锁预防4. 死锁避免系统安全状态，银行家算法。5. 死锁检测和解除三、内存管理（一）内存管理基础1. 内存管理概念程序装入与链接，逻辑地址与物理地址空间，内存保护。2. 交换与覆盖3. 连续分配管理方式4. 非连续分配管理方式分页管理方式，分段管理方式，段页式管理方式。（二）虚拟内存管理1. 虚拟内存基本概念2. 请求分页管理方式3. 页面置换算法最佳置换算法（OPT），先进先出置换算法（FIFO），最近最少使用置换算法（LRU），时钟置换算法（CLOCK）。4. 页面分配策略5. 工作集6. 抖动四、文件管理（一）文件系统基础1. 文件概念2. 文件的逻辑结构顺序文件，索引文件，索引顺序文件。3. 目录结构文件控制块和索引节点，单级目录结构和两级目录结构，树形目录结构，图形目录结构。4. 文件共享5. 文件保护访问类型，访问控制。（二）文件系统实现1. 文件系统层次结构2. 目录实现3. 文件实现（三）磁盘组织与管理1. 磁盘的结构2. 磁盘调度算法3. 磁盘的管理五、输入输出（I/O）管理（一）I/O管理概述1. I/O控制方式2. I/O软件层次结构（二）I/O核心子系统1. I/O调度概念2. 高速缓存与缓冲区3. 设备分配与回收4. 假脱机技术（SPOOLing）. 题型示例一、单项选择题：第140小题，每小题2分，共80分。下列每题给出的四个选项中，只有一项是最符合题目要求的。操作系统1. 下列选项中，不可能在用户态发生的事件是A. 系统调用B. 外部中断C. 进程切换D. 缺页2. 中断处理和子程序调用都需要压栈以保护现场，中断处理一定会保存而子程序调用不需要保存其内容的是A. 程序计数器B. 程序状态字寄存器C. 通用数据寄存器D. 通用地址寄存器/加1操作load R1,x /取x进到寄存器R1中inc R1store x, R1 /将R1的内容存入x/减1操作load R2,xdec R2store x, R23. 有两个并发执行的进程P1和P2，共享初值为1的变量x。P1对x加1，P2对x减1。加1和减1操作的指令序列分别如下所示。两个操作完成后，x的值A. 不可能是-1或3B. 只能为0C. 可能为0、1或2D. 可能为-1、0、1或24. 设与某资源关联的信号量初值为3，当前值为1。若M表示该资源的可用个数，N表示等待该资源的进程数，则M、N分别是A. 0、1B. 1、0C. 1、2D. 2、05. 在支持多线程的系统中，进程P创建的若干个线程不能共享的是A. 进程P的代码段B. 进程P中打开的文件C. 进程P的全局变量D. 进程P中某线程的栈指针6. 下列选项中，满足短任务优先且不会发生饥饿现象的调度算法是（ ）A. 先来先服务B. 高响应比优先C. 时间片轮转D. 非抢占式短任务优先7. 若某单处理器多进程系统中有多个就绪态进程，则下列关于处理机调度的叙述中，错误的是A. 在进程结束时能进行处理机调度B. 创建新进程后能进行处理机调度C. 在进程处于临界区时不能进行处理机调度D. 在系统调用完成并返回用户态时能进行处理机调度8. 在虚拟内存管理中，地址变换机构将逻辑地址变换为物理地址，形成该逻辑地址的阶段是A. 编辑B. 编译C. 链接D. 装载9. 某计算机采用二级页表的分页存储管理方式，按字节编址，页大小为210字节，页表项大小为2字节，逻辑地址结构为：页目录号页号页内偏移量逻辑地址空间大小为216页，则表示整个逻辑地址空间的页目录表中包含表项的个数至少是A. 64B. 128C. 256D. 51210. 在缺页处理过程中，操作系统执行的操作可能是. 修改页表. 磁盘I/O. 分配页框A. 仅、B. 仅C. 仅D. 、和11. 当系统发生抖动（thrashing）时，可以采取的有效措施是. 撤销部分进程. 增加磁盘交换区的容量. 提高用户进程的优先级A. 仅B. 仅C. 仅D. 仅、二、综合应用题：第41 47小题，共70分。1假设计算机系统采用CSCAN（循环扫描）磁盘调度策略，使用2KB的内存空间记录16,384个磁盘块的空闲状态。（1）请说明在上述条件下如何进行磁盘块空闲状态的管理。（2）设某单面磁盘旋转速度为每分钟6,000转，每个磁道有100个扇区，相邻磁道间的平均移动时间为1 ms。若在某时刻，磁头位于100号磁道处，并沿着磁道号增大的方向移动（如下图所示），磁道号请求队列为50、90、30、120，对请求队列中的每个磁道需要读取1个随机分布的扇区，则读完这4个扇区总共需要多少时间？要求给出计算过程。（3）如果将磁盘替换为随机访问的Flash半导体存储器（如U盘，SSD等），是否有比CSCAN更高效的磁盘调度策略？若有，给出磁盘调度策略的名称并说明理由；若无，说明理由。2请求分页管理系统中，假设某进程的页表内容如下表所示： 页号页框（Page Frame）号有效位（存在位）磁盘地址0101H133AH10326H2254H1776H30120H页面大小为4 KB，一次内存的访问时间是100 ns，一次快表（TLB）的访问时间是10 ns，换入一个页面的平均时间为108 ns（已含更新TLB和页表的时间）。进程的驻留集大小固定为2，采用最近最少使用置换算法（LRU）和局部淘汰策略（假设TLB初始为空，地址转换时先访问TLB，再访问页表；有效位为0表示页面不在内存）。（1）依次访问上述三个虚地址：2362H、1565H、25A5H，各需多少访问时间？给出计算过程。（2）基于上述访问序列，计算1565H的物理地址，并说明理由。附录2012年全国硕士研究生入学统一考试计算机科学与技术学科联考计算机学科专业基础综合试题（操作系统部分）一、单项选择题：140小题，每小题2分，共80分。下列每题给出的四个选项中，只有一个选项是最符合题目要求的。23. 下列选项中，不可能在用户态发生的事件是A. 系统调用B. 外部中断C. 进程切换D. 缺页24. 中断处理和子程序调用都需要压栈以保护现场，中断处理一定会保存而子程序调用不需要保存的是A. 程序计数器B. 程序状态字寄存器C. 通用数据寄存器D. 通用地址寄存器25. 下列关于虚拟存储器的叙述中，正确的是A. 虚拟存储器只能基于连续分配技术B. 虚拟存储器只能基于非连续分配技术C. 虚拟存储器只受外存容量的限制D. 虚拟存储器只受内存容量的限制26. 操作系统的I/O子系统通常由四个层次组成，每一层明确定义了与邻近层次的接口，其合理的层次组织排列顺序是A. 用户级I/O软件、设备无关软件、设备驱动程序、中断处理程序B. 用户级I/O软件、设备无关软件、中断处理程序、设备驱动程序C. 用户级I/O软件、设备驱动程序、设备无关软件、中断处理程序D. 用户级I/O软件、中断处理程序、设备无关软件、设备驱动程序27. 假设5个进程P0、P1、P2、P3、P4的共享3类资源R1、R2、R3，这些资源总数分别为18、6、22。T0时刻的资源分配情况如下表所示，此时存在的一个安全序列是进程已分配资源资源最大需求R1R2R3R1R2R3P03235510P1403536P24054011P3204425P4324424A. P0，P2，P4，P1，P3B. P1，P0，P3，P4，P2C. P2，P1，P0，P3，P4D. P3，P4，P2，P1，P028. 若一个用户过程通过read系统调用读取一个磁盘文件中的数据，则下列关于此过程的叙述中，正确的是. 若该文件的数据不在内存，则该进程进入睡眠等待状态. 请求read系统调用会导致CPU从用户态切换到核心态. read系统调用的参数应包含文件的名称A. 仅、B. 仅、C. 仅、D. 、和29. 一个多道批处理系统中仅有P1和P2两个作业，P2比P1晚5 ms到达。它们的计算和I/O操作顺序如下：P1：计算60 ms，I/O 80 ms，计算20 msP2：计算120 ms，I/O 40 ms，计算40 ms若不考虑调度和切换时间，则完成两个作业需要的时间最少是A. 240 msB. 260 msC. 340 msD. 360ms30. 若某单处理器多进程系统中有多个就绪态进程，则下列关于处理机调度的叙述中错误的是A. 在进程结束时能进行处理机调度B. 创建新进程后能进行处理机调度C. 在进程处于临界区时不能进行处理机调度D. 在系统调用完成并返回用户态时能进行处理机调度31. 下列关于进程和线程的叙述中，正确的是A. 不管系统是否支持线程，进程都是资源分配的基本单位B. 线程是资源分配的基本单位，进程是调度的基本单位C. 系统级线程和用户级线程的切换都需要内核的支持D. 同一进程中的各个线程拥有各自不同的地址空间32. 下列选项中，不能改善磁盘设备I/O性能的是A. 重排I/O请求次序B. 在一个磁盘上设置多个分区C. 预读和滞后写D. 优化文件物理的分布二、综合应用题：第41 47小题，共70分。45（7分）某请求分页系统的页面置换策略如下：系统从0时刻开始扫描，每隔5个时间单位扫描一轮驻留集（扫描时间忽略不计），本轮没有被访问过的页框将被系统回收，并放入到空闲页框链尾，其中内容在下一次被分配之前不被清空。当发生缺页时，如果该页曾被使用过且还在空闲页框链表中，则重新放回进程的驻留集中；否则，从空闲页框链表头部取出一个页框。假设不考虑其它进程的影响和系统开销，初始时进程驻留集为空。目前系统空闲页框链表中页框号依次为：32、15、21、41。进程P依次访问的是：、。请回答下列问题。（1）访问时，对应的页框号是什么？（2）访问时，对应的页框号是什么？说明理由。（3）访问时，对应的页框号是什么？说明理由。（4）该策略是否适合于时间局部性好的程序？说明理由。46（8分）某文件系统空间的最大容量为4 TB（1 T =240），以磁盘块为基本分配单位，磁盘块大小为1 KB。文件控制块（FCB）包含一个512 B的索引表区。请回答下列问题。（1）假设索引表区仅采用直接索引结构，索引表区存放文件占用的磁盘块号。索引表项中块号最少占多少字节？可支持的单个文件最大长度是多少字节？（2）假设索引表区采用如下结构：第07字节采用格式表示文件创建时预分配的连续存储空间，其中起始块号占6 B，块数占2 B；剩余504字节采用直接索引结构，一个索引项占6 B，则可支持的单个文件最大长度是多少字节？为了使单个文件的长度达到最大，请指出起始块号和块数分别所占字节数的合理值并说明理由。2013年全国硕士研究生入学统一考试计算机科学与技术学科联考计算机学科专业基础综合试题（操作系统部分）一、单项选择题：140小题，每小题2分，共80分。下列每题给出的四个选项中，只有一个选项是最符合题目要求的。23. 用户在删除某文件的过程中，操作系统不可能执行的操作是A. 删除此文件所在的目录B. 删除与此文件关联的目录项C. 删除与此文件对应的文件控制块D. 释放与此文件关联的缓冲区24. 为支持CD-ROM中视频文件的快速随机播放，播放性能最好的文件数据块组织方式是A. 连续结构B. 链式结构C. 直接索引结构D. 多级索引结构25. 用户程序发出磁盘I/O请求后，系统的处理流程是：用户程序系统调用处理程序设备驱动程序中断处理程序。其中，计算数据所在磁盘的柱面号、磁头号、扇区号的程序是A. 用户程序B. 系统调用处理程序C. 设备驱动程序D. 中断处理程序26. 若某文件系统索引节点（inode）中有直接地址项和间接地址项，则下列选项中，与单个文件长度无关的因素是A. 索引节点总数B. 间接地址索引的级数C. 地址项的个数D. 文件块大小27.设系统缓冲区和用户工作区均采用单缓冲，从外设读入1个数据块到系统缓冲区的时间为100，从系统缓冲区读入1个数据块到用户工作区的时间为5，对用户工作区的1个数据块进行分析的时间为90。进程从外设读入并分析2个数据块的最短时间是A. 200B. 295C. 300D. 39028. 下列选项中，会导致用户进程从用户态切换到核心态的操作是. 整数除以零. sin（）函数调用. read系统调用A. 仅、B. 仅、C. 仅、D. 、和29. 计算机开机后，操作系统最终被加载到A. BIOSB. ROMC. EPROMD. RAM30. 若用户进程访问内存时产生缺页，则下列选项中，操作系统可能执行的操作是处理越界错置换页 访问内存A. 仅、B. 仅、C. 仅、D. 、和31. 某系统正在执行三个进程P1、P2和P3，各进程的计算（CPU）时间