操作系统考试卷子-期中2005-11-1

Test For Operating SystemNo. Name一Fill the blank presented below with appropriate words(1x30 points)1. The most common multiple-processor systems now use__________, in which each processor runs an identical copy of the___________, some systems use___________, in which each processor is assigned a specific task.2.Real-time system come in two flavors: ___________ and___________.3.There are two common models of communication: _____________and_____________.4.Sever systems can be broadly categorized as _________ and_________.5.Each process may be in one of the following states: new、______________、________、terminated.6.System calls provide the interface between_______ and _______.7.________________selects process from the pool and loads them into memory for execution . __________________selects from among the process that are ready to execute and alloctes the CPU to them.8.The operating system must provide a mechanism for process_________and_________9.Supprot for threads may be provided at either the user level, for_____________ , or by the kernel, for_____________.10.There are four main CPU scheduling algorithms: FCFS、________、RR and______11.A solution to the critical-section problem must satisfy the following three requirements:____________、____________、_____________.12.A deadlock situation can arise if the following four conditions hold simultaneously in a system: mutual exclusion、____________、_____________and circular wait 13.Many systems provide support for both user and kernel threads, resulting in different multithreading models. There are three main models:______________、______________、________________.二single-choice(1x20)1. The goal of a time-sharing operating system pursue is ( )A. response immediatelyB. multi-threadC. velocityD. parallel execute2.Multiprocessos system have three main advatages, except ( )五道口生活网A. Increased throughtputB. Economy of scaleC. Increased reliabilityD. Reduce the complexity of OS3.Which operating system have rigid time requirements( )A. Batch mode OSB. Multiprogrammed batch OSC. Time-shared OSD. Real-time OS4.Which one is not the advantages of distributed system? ( )A. Resource sharingB. ReliabilityC. Not a real-time systemD. Communications5.Which one is not the way to enter kernel mode from user mode? ( )A. A special instruction called a supervise or callB. Traps mechanismC. Interrupts mechanismD. Procedure call6. Which task is not performed by an operating system? ( )A. Process managementB. Memory managementC. File managementD. Language management7.The system services provided below, which one is not provided for user, but for ensuring the efficient operation of the system itself ( )A. Program executionB. Communications:C. Error detectionD. Resource allocation8.A PCB contains many pieces of information associated with a specific process, which one is not contained( )A. Process stateB. Program counterC. Fault informationD. CPU register9.The interval from the time of submission of a process to the time of completion is the ( )A. Turanaround timeB. Waiting timeC. Response time五道口生活网D. Context-switch time10.Which one is not the criteria of CPU schedule( )A. CPU utilizationB. ThroughputC. Turnaround timeD. Increased reliability11.Which one is not the reason that we provide an environment that allows process cooperation( )A. Information sharingB. Computation speedupC. ModularityD. Response immediately12.A semaphore S ,initialize to 2 and current value is -1,then how many processes is waiting( )A.0B.1C.2D.313.Which CPU schedule algorithm may lead to the starvation problem( )A. First-Come, First-ServedB. Shortest-Job-FirstC. Round-Robin14.Which one below is not the benefits of multithreaded program ( )A. Increase reliabilityB. ResponsivenessC. Resource sharingD. Economy15.Which solution is used in UNIX to deal with the deadlock problem ( )A. Use a protocol to prevent deadlock, ensuring that the system will never enter a deadlock state.B. Allow the system to enter a deadlock state, detect it, and recover.C. Ignore the problem altogether, and pretend that deadlock never occur in the system.D.both A and B16.Bankers Algorithm is used to deal with the ( )A. starvation problemB. process communicationC. Deadlock problemD. Process synchronization problem17.Which one is not the classic problem of Synchronization ( )A. The Bounded-Buffer problemB. The Readers-Writers Problem五道口生活网C. The Ding-Philosophers ProblemD. The Starvation Problem18.There are three concurrent processes in the system, each of them require four instances of the same type resource, then how many instances are needed at least to avoid deadlock( )A.9B.10C.11D.1219.A critic section is( )A. a segment of dataB. a segment of codeC. buffersD. I/O devices20.Which one is high-level synchronization construct( )A. monitorB. semaphoreC. synchronization hardwareD. binary semaphore三Answer the questions in the space provided below each question.e the semaphore Full、empty and mutex to solve the bounded-buffer problem(5 points)2.Consider the following set of processes, with the length of the CPU-burst time given in millionseconds :Process Burst Time PriorityP1 10 3P2 1 1P3 2 3P4 1 4P5 5 2The processes are assumed to have arrived in the order P1, P2, P3, P4, P5 all at time 0.a.Draw two Gantt charts illustrating the execution of these processes using FCFS, anonpreemptive priority (a smaller priority number implies a higher priority) scheduling. (5 points)五道口生活网b.What is turnaround time of each process for RR (quantum=1) scheduling. (5points)c.What is the waiting time of each process for SJF scheduling.(5 points)3.Conside the following snapshot of a system:Allocation Max AvailableA B C D A B C D A B C DP0 0 0 1 2 0 0 1 2 1 5 2 0P1 1 0 0 0 1 7 5 0P2 1 3 5 4 2 3 5 6P3 0 6 3 2 0 6 5 2P4 0 0 1 4 0 6 5 6Answer the following questions using the bankers algorithm:a.What is the content of the matrix Need?(5 points)b.Is the system in a safe state? If not, explain why. If the system is in a safe state ,then write all the safe sequences(5points)c.If a request from process P1 arrives for (0,4,2,0), can the request be grantedimmediately?(5 points)五道口生活网4. The sets P、R、and E of a resource-allocation graph are shown as follows P={P1、P2、P3}R={R1、R2、R3、R4}E={P1→R1、P2→R3、R1→P2、R2→P2、R2→P1、R3→P3、P3→R2、R4→P3} Resource instances:One instance of resource type R1Two instance of resource type R2One instance of resource type R3Three instance of resource type R4a.Drawn the resource-allocation graph(5 points)b.Is the system in s safe state or not? explain why.(5 points)5.write some methods that can be used to solve the Dining-Philosophers Problem (describe these methods just in nature language) (5 points)五道口生活网五道口生活网。