武汉大学 学年度第 1 学期 多核架构及编程技术 试卷(A)

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1 武汉大学 学年度第 学期 多核架构及编程技术 试卷(A) 学院专业班学号姓名分数 注 : 请在答题纸上答题 答案写在试卷纸上无效 考试完毕, 请将答题纸与试卷纸一起上交 一 填空题 ( 共 20 分, 每题 2 分 ) When threads are scheduled for execution, Windows choose which processor should run it. This policy used in selecting the processor is called. 2 In windows system, resources are represented as a kernel object identified and referenced by a. 3 is a WI32 API which creates a Windows thread that begins execution of the function provided as the fourth parameter. 4 When success, the Create Thread function returns a that used to reference the thread that is created. 5 A is a special case of a semaphore that grants exclusive access of the critical section to only one thread. 6 In Win32 multi-thread programming, multiple threads within an application need a mechanism that can be used for inter-thread communication. Windows has provided objects that can be used for this purpose. 7 In Win32 Events programming, windows provides the function () to signal the thread when it is time to terminate. 8 Traditionally, the word is used for systems in which the executions of several programs overlap in time by running them on separate processors. 9 In C#, a is the equivalent of an address of a function in C. 0 In.ET threading API, the function is used to create a new thread. 二 单选题 ( 共 20 分, 每题 分 ) "Process" is different from "Program" because. A. program has status, process don't B. process has status, program don't C. program can occupy resource, process don't D. process can occupy resource, program don't 2 In Operation System, What is the basic unit that can be executed concurrently and scheduled by kernel? A. Task B. Course C. Process D. Function 3 A process is constructed by. A. data, ID and PCB(Process Control Block) B. code, ID and PCB C. code, data and ID D. code, data and PCB 4 There are (>2) threads in system. Which of the following is impossible? A.One thread is running.the rest - threads are ready.one is waiting. B.One thread is running.one is ready.the rest - threads are waiting. C.one is running.two threads are ready.the rest -2 threads are waiting. D.One thread is running.one thread is ready.the rest -2 threads are waiting. 5 Which of the following is right about the concurrent threads?

2 A.They are independent. B.They must be synchronized. C.They must be mutual exclusion. D.They may need to be synchronized or mutual exclusive,but not necessary. 6 Critical Section is. A.a buffer. B.a data section. C.a code section. D.a Synchronization mechanism. 7 A thread has performed a "P operation" to a semaphore.if the semaphore's value,the thread will be blocked. A.>0. B.<0. C.>=0. D.<=0. 8 The deadlock will be avoided if we allocated resources statically. What is the reason? A. There is no mutual exclusion. B. The resource can not be robed. C. Threads won't be waiting for others in a cycle. D. Threads can release their resources when requesting a new resource. 9 Assume there is a bridge that can be come across by only car at the same time. Which of the following codes can make sure that the car can come across this bridge safely? A. Semaphore S=2; P(S); Arrive at the other end of the bridge; B. Semaphore S=2; P(S); Arrive at the other end of the bridge; V(S); C. D. Semaphore S=; Semaphore S=; P(S); P(S-); Arrive at the other end of the bridge; Arrive at the other end of the bridge; V(S); V(S+); 0 All processes start with a single thread of execution: the main thread. In order to write multi-threaded code, one must have the ability to create new threads.which of the following is the most basic thread creation mechanism provided by Microsoft? A.new Thread() B.CreateThread() C._beginthreadex() D.AfxBeginThread() Microsoft defines several different types of synchronization objects as part of the Win32 API. These include events, semaphores, mutexes, and critical sections.the CRITICAL_SECTIO API defines a number of functions that operation on CRITICAL_SECTIO objects. Which of the followings is not the function of CRITICAL_SECTIO API? 2

3 A.EnterCriticalSectiion() B.DeleteCriticalSection() C.ReEnterCriticalSection() D.InitializeCriticalSectiion() 2 which of the following statements about Windows OS is wrong? A.Windows is object-oriented system. B.The Windows thread is the basic unit of execution. C.Kernel objects must be manipulated by Windows APIs. D.Resources are represented as a kernel object identified and referenced by a handle. 3 which of the following about DWORD in MFC is right? A.32 bits,signed B.64 bits,signed C.32 bits,unsigned D.64 bits,unsigned 4 there are many functions used in windows programming,such as function HADLE CreatFile ( LPCTSTR lpame, DWORD dwaccess, DWORD dwsharemode, LPSECURITY_ATTRIBUTES lpsecurityattributes, DWORD dwcreate, DWORD dwattrsandflags, HADLE htemplatefile ). The parameter dwcreate specifies whether to create a new file,whether to overwrite an existing file,and so on. Which of the following statements about parameter dwcreate's value CREATE_EW is true? A.Fail if the file does not exist. B.An existing file will be overwritten. C.Open the file,creating it if it does not exist. D.Fail if the specified file already exists;otherwise,creat a new file. 5 Which of the following functions is used to make a thread to wait on multiple threads? A.pthread_join() B.pthread_create() C.pthread_detach() D.pthread_mutex_wait() 6 The thread is able to run, but is waiting for a processor. It may have just started, or just been unblocked, or preempted by another thread. Which of the following state is right to describe this situation? A.Ready B.Blocked C.Running D.Terminated 7 Which of the following header file must be included when we want to use OpenMP* API? A.omp.h B.time.h C.stdio.h D.windows.h 8 The is all about examining to see that a threaded program is not plagued by coding errors in how threads interoperate that can cause the program to fail. A. Intel Debugger B. Intel Thread Profiler C. Intel Thread Checker D. Intel VTune Performance Analyzer 9 You can use function to create a pthread. A. pthread_create B. create_pthread C. new(pthread_t) D. pthread_t pt 20 Which of the following is OT the basic process state? A. Died B. Ready C. Running D. Blocked 3

4 三 多选题 ( 一个以上答案正确, 共 20 分, 每题 2 分 ) which of the following OS features belong to windows system essentials? A.memory B.file systems C.multitasking D.security and protection E.resource naming and location F.communication and synchronization 2 Which of the following are the atomic operations defined on a semaphore S? A. signal B. sleep C. lock D. wait 3 Which of the following sentences about messages are right? A. Two threads that communicate with messages and reside in the same process use intra-process messaging. B. Message Passing is a special method of communication between processes. It can not be applied to threads communication C. From a message-sharing perspective, messages get shared using an intro-process, inter-process, or process-process approach. D. In general, the messaging could not be devised according to the memory model of the environment where the messaging operation takes place. 4 Which of the following judgments about synchronize operations are right? A. The generic form of message passing gives the impression to developers that there must be some interface used to perform message passing, the MPI. B. To synchronize operations of threads, semaphores, locks, and condition variables are used, these synchronization primitives convey status and access information using thread messaging. C. The basic operational concepts of messaging remain the same for all operational models, from an implementation point of view, the generic client-server model can be used for all messaging models. D. In thread messaging, synchronization remains explicit, as there is acknowledgement after receiving messages. The acknowledgement can not avoid primitive synchronization errors, such as deadlocks or race conditions. 5 In WI32 thread APIs,there are three function can create a thread, which of the following are the right answers? A.new Thread() B.CreateThread() C._beginthreadex() D.AfxBeginThread() 6 Microsoft defines several different types of synchronization objects as part of the Win32 API. These include events, semaphores, mutexes, and critical sections.which of the followings are the APIs related to mutex? A.InitMutex() B.OpenMutex() C.CreateMutex() D.ReleaseMutex() 7 Which of the following are correct about synchronous and asynchronous communications? A. In synchronous communication, the sender will be blocked if the receiver is not ready B. The asynchronous communication is usually implemented in hardware C. The synchronous communication must require a buffer D. is asynchronous communication 8 Which of the following problem is not caused by mutual exclusion? A. Many students borrow the same book from the library. 4

5 B. Two basketball player play with one basketball. C. The working procedure of the assembly line. D. Product produce and social consuming. 9 In contrast to synchronous systems, the asynchronous systems have the specifications that A. high efficient B. Low efficient C. deadline are strictly met D. deadline are not met strictly 0.Look at the following code segment: for Which of the following code segments are equal to this code segment? #pragma omp for #pragma omp for for A B C D 四 简答题 ( 共 24 分, 每题 6 分 ) 线程状态图如图 所示, 说明 A B C 分别代表何种状态? 图 线程状态图 2 简要说明 Flynn 分类法 3 什么是线程 进程, 区别是什么? 4 由于线程共享同一进程的内存空间, 多个线程可能需要同时访问同一个数据, 如果没有正确的保护措施, 对共享数据的访问会造成数据的不一致和错误 简述常用的几种同步机制 5

6 五 编程题 ( 共 20 分 ) 设计并行程序计算圆周率 π 提示 : 已知 : dx = arctan( x) 0 = arctan() arctan(0) = arctan() = π / x 设 : f 4 x) = ( + x ( 2 可得 : f ( x) dx = π 0 ) 2 i 2 于是 : π = f ( ) = i= i= i 0.5 f ( ) 6