Deck 10: Multithreading Networks and Client Server Programming

Question 1

Time-sharing systems are still in widespread use in the form of Web servers, e-mail servers, print servers, and other kinds of servers on networked systems.

Answer 1

True

Question 2

A thread object can die if it raises an exception that is not handled.

Answer 2

True

Question 3

The most common way to create a thread is to define a class that extends the class threading.Runnable.

Answer 3

False

Question 4

Clients connect to servers via objects known as channels.

Question 5

Producer/consumer threads can suffer from synchronization problems.

Question 6

A port serves as a channel through which several clients can exchange data with the same server or with different servers.

Question 7

Ports are usually specified by IP addresses.

Question 8

Because an IDLE itself runs in a thread, it is not generally a good idea to test a multithreaded application in that environment.

Question 9

The late 1960s and early 1970s saw the rise of networked systems.

Question 10

Threads cannot share data between them.

Question 11

You cannot create and open several sockets on the same port of a host computer.

Question 12

The process of saving or restoring a thread's state is called a scheduling switch.

Question 13

A thread's block method is invoked automatically by start.

Question 14

When developing a network application, the programmer can first try it out on a local host-that is, on a standalone computer that may or may not be connected to the Internet.

Question 15

In Python, a thread is an object like any other in that it can hold data, be run with methods, be stored in data structures, and be passed as parameters to methods.

Question 16

To properly handle functions that may raise exceptions, you can embed these function calls in a try-catch statement.

Question 17

The release() method of the Condition class relinquishes the lock, leaving it to be acquired by others.

Question 18

Few modern computers use threads to represent processes.

Question 19

When a thread's run method has executed its last instruction, the thread dies as a process but continues to exist as an object.

Question 20

The notify() method of the Condition class lets all threads waiting on the lock know that it's available.

Question 21

What thread method can be used to test if the thread is dead or not?

A) isDead()
B) isAlive()
C) isActive()
D) isQueued()

Question 22

After the creation of a thread, what makes a thread "ready"?

A) The calling of the start method.
B) The calling of the ready method.
C) The instantiation of the thread, followed by the use of the "begin" function.
D) The creation of the thread itself places it in a "ready" state.

Question 23

What two thread condition methods can be used to release a lock? (Choose two.)

A) notify()
B) release()
C) notifyAll()
D) wait()

Question 24

A server can send data to a client using a socket's put method.

Question 25

A socket resembles a file object, in that the programmer opens it, receives data from it, and closes it when finished.

Question 26

The procedure by which a process's state is saved before being swapped out of the CPU, then us restored to the state when the process is about to execute, is known as?

A) processing handling
B) context switching
C) state cycling
D) priority slicing

Question 27

What does the socket module function gethostname() do?

A) It returns the IP number of the computer whose IP name is passed to the function.
B) It returns the IP address of the host computer running the Python interpreter.
C) It returns the name of the host computer running the Python interpreter.
D) It returns the name of the IP address passed to it.

Question 28

When working with sockets, it is important to synchronize the sending and the receiving of messages between the client and the server.

Question 29

What two Python data structures are already thread-safe, because they provide automatic support for synchronizing multiple readers and writers? (Choose two.)

A) tuples
B) strings
C) lists
D) dictionaries

Question 30

What statement accurately describes the role of a socket?

A) A socket is an object that serves as a communication link between a single server process and a single client process.
B) A socket is a named pipe that is used to pass communications one way to a remote location.
C) A socket is a unique computer resource that provides access to hardware.
D) A socket is a communications channel within the TCP/IP stack that communicates only with the localhost.

Question 31

Using the "gethostbyname('localhost')" function of the socket module will return what IP address?

A) 10.0.0.1
B) 127.0.0.1
C) 169.254.1.1
D) 192.168.1.1

Question 32

What is the purpose of a condition object in a threaded application?

A) The condition object functions as a lock on a resource.
B) The condition object provides a similar function to if-else in threads.
C) The condition object provides a try-except function in threads.
D) The condition object functions as a timer for the ready-queue.

Question 33

The discipline of building hardware architectures, operating systems, and specialized algorithms for running a program on a cluster of processors is known by what term?

A) multi-computing
B) resource sharing
C) process distributing
D) parallel computing

Question 34

A thread that is waiting for user input is most likely in what state?

A) A time-out state.
B) A sleeping state.
C) A blocking state.
D) A wait state.

Question 35

A socket is bound to an address (host, port) by running its bind method.

Question 36

What two items must be passed in a tuple to the socket module's connect method in order to connect a socket? (Choose two.)

A) The target host's IP address.
B) The protocol type that will be used.
C) The operating system used by the host.
D) A valid port number.

Question 37

In the event that a thread loses access to the CPU, such as via a time-out, sleep, block, or wait state, what happens when the thread is ready to resume execution?

A) The thread is moved to the front of the ready-queue.
B) The thread is moved to the rear of the ready-queue.
C) The thread is given a chance to execute as soon as the running process enters a wait state.
D) The thread is given a random interval to check if it is the thread's turn to execute, or if the processor is available.

Question 38

What kind of problem occurs in a producer/consumer relationship in which the consumer attempts to access data that are not there, or accesses the same data more than once?

A) procedural problems
B) communication problems
C) coordination problems
D) synchronization problems

Question 39

The Python function time.currenttime returns a string representing the day/time.

Question 40

In order to execute code in a thread as a process, what must be done?

A) The thread's class must implement a run method.
B) The thread's class must implement an exec method.
C) The thread must include the "process" class as a parent.
D) The thread must be told to execute using the exec=yes key.

Question 41

What two items must be given to the socket function in order to create a socket object?

A) The IP address to be used.
B) The socket family that will be used.
C) The socket type that will be used.
D) The socket port that will be used.

Question 42

When a client connects to a server, what does the socket accept method return?

A) A string containing the client's IP address.
B) A list containing the client's IP address and port.
C) A tuple containing the client's socket and its address information.
D) A bytes object containing the client's IP address.

Question 43

A program starting another program or a new process is known by what term?

A) spawning
B) forking
C) cloning
D) generating

Question 44

In order to utilize the socket module's recv method, what must you pass as an argument?

A) The source IP address the information will be coming from.
B) The destination port you will receive information on.
C) The maximum size in bytes of the data to be read from the socket.
D) The address family used by the network socket.

Question 45

After using the socket.recv method, what type of data is returned?

A) An object of type bytes.
B) A list object containing lines of data separated by carriage returns.
C) A string containing all data that was received.
D) A Boolean value indicating whether the receive was successful.

Question 46

Assuming that a socket has been created with a name of server, what effect does the server.listen(10) have?

A) The socket will listen for a maximum of 10 minutes, and then close.
B) The socket will allow a maximum of 10 connections, then close.
C) The socket will accept a maximum of 10 concurrent connections.
D) The socket will listen until the integer "10" is seen in the data stream.

Question 47

What is the socket bind method used for?

A) It binds the socket to a IP address.
B) It binds the socket to a port.
C) It binds the socket to a listening pipe.
D) It binds the socket to the localhost.

Question 48

You have just captured data using the socket.recv method into a variable named client_data. What can you use to convert client_data to a string?

A) codecs.decode(client_data, "string")
B) socket.decode(client_data, type="string")
C) codecs.decode(client_data, 'ascii')
D) network.data(client_data, %s)

Question 49

You are designing a script that needs to get the current date and time as a string. What function can you use for this?

A) time.ptime
B) time.ctime
C) time.today
D) time.now

Question 50

Which of the following is an example of time slicing?

A) A running process is automatically moved to the rear of the ready queue after a few milliseconds of run time.
B) A process is put to sleep as a result of the sleep method, and moves to the rear of the ready queue.
C) A process is waiting for input from a user and is moved to the rear of the ready queue.
D) A process is waiting for a condition to become true, and is moved to the rear of the ready queue.