操作系统 第3章

Chapter 3 – Process Description and Control
True / False Questions:
1.T / F – The principal function of the processor is to execute machine
instructions residing in main memory.处理器的主要功能是处理驻留在主存中的指令。

ANS: T
2.T / F – A process trace is a listing of the sequence of instructions that execute
for that process.进程指令追踪就是这个进程的指令序列的列表。

ANS: T
3.T / F – The principal responsibility of the operating system is to control the
execution of processes.操作系统的主要任务是控制进程的执行。

ANS: T
4.T / F – When one process spawns another, the spawning process is referred to as
the child process and the spawned process is referred to as the parent process.当一个进程派生出另一进程时，产生进程的进程是子进程，被产生的进程是父进程。

ANS: F (opposite is true)
5.T / F – Round-Robin processing refers to a method of thread prioritization for
scheduling.轮转是一种线程优先级调度方法。

ANS: F (not prioritized)
6.T / F – The primary difference between the Two-State Process Model and the Five-
State Process Model is that the latter splits the Running state into two new
states: Ready and Blocked.两状态处理模型和五状态处理模型主要区别是后者将运行态分割成就绪和阻塞态。

ANS: F (splits the Not Running state)
7.T / F – One solution to the problem of limited main memory space is swapping,
which involves moving all or part of a process from main memory to secondary
memory. 一种解决主存空间有限的方法是交换，这种交换包括将一个进程的全部或部分从主存转移到辅存。

ANS: T
8.T / F – In order to define the control structures (e.g., tables) that the O/S
needs to manage processes and resources, it must have access to configuration data
during initialization.为了定义操作系统控制进程和资源所需要的控制结构，操作系统在初始化的时候必须拥有对设备数据的控制权。

ANS: T
9.T / F – The Process Image refers to the binary form of the program code.
进程映像指的是二进制形式的程序码。

ANS: F (refers to process elements: program, data, stack & attributes)
10.T / F – The portion of the Process Control Block that consists of the contents of
the processor registers is called the Process Control Information.进程控制块中包含处理器寄存器的部分是进程控制信息。

ANS: F (processor state information portion of the PCB contains registers)
11.T / F – The less-privileged processor execution mode is often referred to as
kernel mode.没有特权的处理器执行模式通常被叫做内核模式。

ANS: F (user mode)
12.T / F – The primary process table contains one entry per process, unless the
process spawns a new process, in which case the table contains multiple entries for the parent process. 主进程表中每个进程有一个入口，除非进程产生了子进程，这种情况下表中会有多个到父进程的入口。

ANS: F (only one entry for the parent process)
13. T / F – One kind of system interrupt, the trap, relates to an error or exception
condition in the currently running process.陷阱，一种系统中断，是涉及当前进程中的错误或异常条件。

ANS: T
14. T / F – In the Nonprocess Kernel approach to defining the relationship between
the O/S and the User Process, the O/S code is executed as a separate entity that operates in privileged mode. 采用无进程内核方法来定义操作系统和用户进程的区别：操作系统代码是作为独立的整体在特权模式下运行。

ANS: T
15. T / F – A typical UNIX system employs two Running states, to indicate whether
the process is executing in user mode or kernel mode.典型的UNIX系统采用两种运行态来表示进程是运行在用户模式还是内核模式。

ANS: T
Multiple Choice Questions:
1.The behavior of a processor can be characterized by examining:
一个处理器的行为可以通过对进程的交错的观察来衡量.
A A single process trace
B Multiple process traces
C The interleaving of the process traces
D All of the above
ANS: C
2.The behavior of an individual process can be characterized by examining:
一个单独进程的行为可以通过观察此进程的痕迹来描述.
A A single process trace
B Multiple process traces
C The interleaving of the process traces
D All of the above
ANS: A
3.The basic Two-State Process Model defines two possible states for a process in
relationship to the processor:基本的两状态进程模型定义了一个进程与处理器关系可能的两种状态:进行态和非运行态.
A Running and Executing
B Running and Not Running
C Executing and Waiting
D None of the above
ANS: B
4.There are a number of conditions that can lead to process termination, including:
导致进程终止的条件有:正常结束,越界,父进程终止.
A Normal completion
B Bounds violation
C Parent termination
D All of the above
ANS: D
5.In the Five-State Process Model, the following represents a valid state transition: 在五状态模型中,下列哪一项是有效的转换:运行→阻塞.
A Running -> Blocked
B New -> Running
C New -> Blocked
D All of the above
ANS: A
6.In a Process Model that implements two suspend states, a valid state transition is
represented by:
在两个挂起态的进程执行模型中,有效的转换是:就绪挂起→就绪,进行→就绪挂起,就绪→就
绪挂起.
A Ready/Suspend -> Ready
B Running -> Ready/Suspend
C Ready -> Ready/Suspend
D All of the above
ANS: D
7.The scheduling strategy where each process in the queue is given a certain amount
of time, in turn, to execute and then returned to the queue, unless blocked is
referred to as.一种调度策略,每个在队列中的进程给一定的时间执行,然后返回队列,除非被
阻塞,这个策略叫轮转.
A Prioritization
B Round-Robin
C LIFO
D All of the above
ANS: B
8. A Memory Table is an O/S control structure that is used by the O/S to:
存储页表是用来追踪主存和和辅存的操作系统控制结构.
A Manage I/O devices
B Manage processes
C Provide information about system files
D None of the above
ANS: D (used to keep track of main “real” and secondary “virtual” memory)
9.The Process Image element that contains the collection of attributes needed by the
O/S to control a particular process is called the:
操作系统控制一个特定的进程所需包含一系列进程属性的映象元素叫进程控制块.
A User Data
B System Stack
C Process Control Block
D None of the above
ANS: C
10.The Process Image element that contains the modifiable part of the user space is
called the:
进程控制元素中包含可修改部分的用户空间叫用户数据.
A User Program
B System Stack
C Process Control Block
D None of the above
ANS: D (User Data)
11.The processor execution mode that user programs typically execute in is referred
to as:
执行用户程序的处理器执行方式叫用户模式.
A User mode
B System mode
C Kernel mode
D None of the above
ANS: A
12.One step in the procedure for creating a new process involves:
创建一个新进程包括的步骤:初始化进程控制块,分配进程空间,确实惟一的进程标志号 .
A Initializing the process control block
B Allocating space for the process
C Assigning a unique identifier
D All of the above
ANS: D
13. A process switch may occur when the system encounters an interrupt condition,
such as that generated by a:
当遇到以下哪些情况下进程会发生转换:内存缺页,系统调用,陷阱.
A Memory fault
B Supervisor call
C Trap
D All of the above
ANS: D
14. In the Process Based O/S:
在基于操作系统的进程中:主要的内核函数是独立组织的.
A Major kernel functions are organized as separate functions
B The User Process Image includes a kernel stack
C O/S code and data are contained in the shared address space
D None of the above
ANS: A
15. In a typical UNIX system, the element of the process image that contains the
processor status information is the:
在一个典型的UNIX系统中,进程映像元素中包含进程身份的信息是寄存器上下文.
A System-level context
B Register context
C User-level context
D All of the above
ANS: B
Fill-In-The-Blank Questions:
1.The listing of a sequence of instructions that execute for a particular process is
called a ___________________.
一个进程的指令序列叫指令追踪.
ANS: trace
2.The behavior of a processor can be characterized by examining the interleaving of
the process ____________ for the processes currently running on the system.
ANS: traces
处理器行为可以通过检测当前运行进程追踪的交换来描述.
3.The portion of the operating system that selects the next process to run is called
the _______________.
选择下一进程的操作系统部分叫调度器.
ANS: dispatcher
4.When the O/S creates a process at the explicit request of an existing process, the
action is referred to as _______________________.
当操作系统在现有进程的明确要求下创建了一个进程,这种行为叫子进程创建.
ANS: process spawning
5. A process that cannot execute until some event occurs is said to be in the
_______________ state.
一个进程直到某些事件发生才能执行,我们说进程处于阻塞态.
ANS: blocked
6.In a system that implements two suspend states, a process that has been swapped
out of main memory and into secondary memory and that is also awaiting an event is in the ________/________ state.
一个两挂起态的系统,一个进程从主存转移到辅存并且等待一个事件的完成时,处于阻塞挂起态.
ANS: Blocked/Suspend
7.The scheduling strategy where each process in the queue is given a certain amount
of time, in turn, to execute and then returned to the queue, unless blocked is referred to as _______________.
一种调度策略,队列中的每一进程在不被阻塞的情况下给予一定的时间执行,然后返回队列,这种策略叫轮转.
ANS: round-robin
8.The O/S control structure that the O/S uses to manage system processes is called
the ________________.
操作系统用来控制进程的控制结构叫进程控制表
ANS: process table
9.The User Data, User Program, System Stack and Process Control Block elements
collectively make up what is referred to as the __________________.
用户数据,用户程序,系统栈，进程控制块是进程映象中的典型元素。

ANS: process image
10. The Process Identification, Processor State Information and the Process Control
Information are the general categories that collectively make up what is referred to as the _________________.
进程标识，处理器状态信息，进程控制信息是进程控制块中的典型元素。

ANS: process control block
11.The processor typically maintains the current operating mode (i.e., user or kernel)
in the _________________.
处理器在程序状态字中记录了当前的操作模式。

ANS: program status word (PSW)
12.The first step in creating a new process is to assign a unique ________________ to
the new process.
创建一个进程的第一步是为进程分配一个唯一的标识号。

ANS: process identifier
13. The execution of a user process may be interrupted by a __________________, which
might be generated by the process requesting an I/O operation.
用户进程的执行有可能被系统调用中断，此中断有可能是请求I/O操作所致。

ANS: supervisor call
14. In the __________________ model for illustrating the relationship between the O/S
and User Processes, the O/S has its own region of memory to use and its own system stack for controlling procedure calls and returns.
在独立内核模式下解释操作系统和用户进程关系时，操作系统有自己独立的内存和系统栈来控制程序调用和返回。

ANS: separate kernel
15.In the __________________ model for illustrating the relationship between the O/S
and User Processes, the O/S has its own region of memory to use and its own system stack for controlling procedure calls and returns.
在短程调度模式下解释操作系统和用户进程关系时，操作系统有自己独立的内存和系统栈来控制程序调用和返回
ANS: short-term
16. Process creation in a typical UNIX system is made by means of a kernel system
call named _______________.
在UNIX系统中，进程创建是通过叫作fork()的系统调用函数完成的。

ANS: fork()。