Java Multithreading and Buffering
40 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the purpose of the sleep(10000) function in the Consumer class?

To wait for 10 seconds before starting work.

What is the main objective of the programming task in Exercise 2 - Lab 1 Preparation?

To develop the control program for an alarm clock.

What are the three main parts of the interface between the control software and the hardware?

Input, Output, and Time.

What is the name of the package that models the functionality of the hardware?

<p>done</p> Signup and view all the answers

What is the purpose of the Buffer class in the given code?

<p>To hold and manage data for the consumer thread.</p> Signup and view all the answers

What is the purpose of the run() method in the Consumer class?

<p>To start the execution of the consumer thread.</p> Signup and view all the answers

Why is the try-catch block used in the run() method of the Consumer class?

<p>To handle exceptions and let the thread terminate.</p> Signup and view all the answers

What is the role of the emulator in the laboratory session?

<p>To emulate the hardware for testing the control software.</p> Signup and view all the answers

What is started by the simulator after creating an instance of the AlarmClock class?

<p>A new thread.</p> Signup and view all the answers

What method does the new thread start executing?

<p>The <code>AlarmClock.run()</code> method.</p> Signup and view all the answers

What is the purpose of the ClockInput interface?

<p>To handle user actions via hardware/software.</p> Signup and view all the answers

What is the purpose of the ClockOutput interface?

<p>To display information on the hardware/software.</p> Signup and view all the answers

What is the purpose of the AlarmClock class?

<p>To implement the actual alarm clock software.</p> Signup and view all the answers

What happens when the applet is stopped?

<p>There is a call to <code>control.terminate()</code>.</p> Signup and view all the answers

What is the purpose of the doAlarm() method?

<p>To wake up the clock user.</p> Signup and view all the answers

What is needed to fulfill the optional specification item 5?

<p>To override the <code>terminate()</code> method.</p> Signup and view all the answers

What is the primary objective of the lab preparation in designing a real-time system for the AlarmClock?

<p>To design a real-time system for the AlarmClock using threads, semaphores, and provided hardware interfaces.</p> Signup and view all the answers

What are the two Java packages provided in the handout code for the AlarmClock assignment?

<p>The two packages are 'done' and 'todo'.</p> Signup and view all the answers

What is the limitation of the ClockOutput.doAlarm() method in the provided code?

<p>It only makes one beep.</p> Signup and view all the answers

What is the purpose of the Semaphore object in the AlarmClock class?

<p>It is used for synchronization and mutual exclusion.</p> Signup and view all the answers

What is the effect of calling sleep(1000) in a thread to wait for the next second?

<p>It will cause the clock time to be inaccurate.</p> Signup and view all the answers

What type of data structures are needed to support concurrent access from different threads?

<p>Global data structures with mutual exclusion using semaphores or mutexes.</p> Signup and view all the answers

What is the purpose of the MutexSem class in the provided code?

<p>It is used to implement mutual exclusion and synchronization.</p> Signup and view all the answers

What is the primary goal of the AlarmClock class in the provided code?

<p>To implement a real-time system that beeps upon key presses.</p> Signup and view all the answers

What is the primary concern in developing the GUI classes, and how does this impact the control software?

<p>The primary concern is ensuring the classes developed will run on real hardware without changes to the source code, and as a result, these classes cannot be accessed from the control software.</p> Signup and view all the answers

How frequently should the displayed clock time be updated, and what happens when the user selects Set alarm or Set time?

<p>The displayed clock time should be updated every second, and when the user selects Set alarm or Set time, the hardware/emulator shows the set time and an update of the clock time will have no effect on the clock.</p> Signup and view all the answers

How are synchronization and mutual exclusion handled in this system, and what is the purpose of this approach?

<p>Synchronization and mutual exclusion are handled using semaphores, which allows for efficient and safe concurrent access to shared resources.</p> Signup and view all the answers

What happens when the clock time equals the alarm time and the Alarm on is selected, and how can the alarm sound be terminated?

<p>The alarm should beep once a second for 20 seconds, and the sound can be turned off by pushing any button while the alarm is sounding.</p> Signup and view all the answers

How is the user's input handled when setting the clock time or alarm time, and what is the role of the ClockInput object?

<p>The user's input is handled internally by the hardware/emulator, and the set value is written to the ClockInput object, which triggers the semaphore's give method.</p> Signup and view all the answers

What is the purpose of the additional information panel below the actual clock panel, and how does it impact testing?

<p>The additional information panel displays the clock time for verification and convenience during testing, ensuring that the software accurately keeps track of time.</p> Signup and view all the answers

What programming language and concurrency mechanism are required for this system, and why?

<p>The program should be written in Java, using the Thread class, and all synchronization and mutual exclusion should be achieved by using semaphores.</p> Signup and view all the answers

How does the system handle the transition between modes, such as when the user selects another mode after setting the alarm or clock time?

<p>When the user selects another mode, the set value is written to the ClockInput object and the semaphore's give method is called.</p> Signup and view all the answers

What is the purpose of the Semaphore in the ClockInput class?

<p>To signal when the user has changed any setting.</p> Signup and view all the answers

What is the return type of the getSemaphoreInstance() method?

<p>Semaphore</p> Signup and view all the answers

What is the purpose of the alarmOn attribute in the ClockInput class?

<p>To indicate if the alarm is activated according to the checkbox.</p> Signup and view all the answers

What is the purpose of the getAlarmFlag() method?

<p>To get the checkbox state.</p> Signup and view all the answers

What is the purpose of the getChoice() method?

<p>To get the radio-button choice.</p> Signup and view all the answers

What is the format of the return value of the showTime() method?

<p>hhmmss, where h, m, and s are hours, minutes, and seconds digits respectively.</p> Signup and view all the answers

What is the purpose of the lastValueSet attribute in the ClockInput class?

<p>To store the last value set by the user.</p> Signup and view all the answers

What is the purpose of the SET TIME, SET ALARM, and SHOW TIME constants?

<p>To represent the different states of the clock display.</p> Signup and view all the answers

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser