Concurrent Programming, JAVA Programming

Assignment Help:
Problem 1
A savings account object holds a non-negative balance, and provides deposit(k )
and withdraw(k ) methods, where deposit(k ) adds k to the balance, and
withdraw(k ) subtracts k, if the balance is at least k, and otherwise blocks until
the balance becomes k or greater. getbalance() gives the current balance.
1. Implement this savings account using locks and conditions (use
java.util.concurrent.locks.ReentrantLock). Test by using the 3
functions.
2. Now suppose there are two kinds of withdrawals: ordinary and preferred.
Devise an implementation that ensures that no ordinary withdrawal occurs
if there is a preferred withdrawal waiting to occur.
Problem 2
Consider the following conditions: An enqueuer waiting on a full-queue or
a dequeuer waiting on an empty queue sleep indefinitely, unless woken up by
another thread. A thread must send a signal ONLY when it adds an element
to an empty queue or removes an element from a full-queue.
1. Implement a bounded partial queue using a signaling mechanism that
signals to all waiting dequeuers.
2. Implement the bounded partial queue by using a signaling mechanism
(your own scheme) that signals to only one waiting dequeuer or enqueuer,
and ensure that the lost-wake-up problem does not happen.
1
Problem 3
We have n threads, each of which executes method foo() followed by bar().
We want to add synchronization to ensure that no thread starts executing bar()
until all threads have finished executing foo(). To achieve this, we will insert
some barrier code between the two methods. Implement the following two
schemes for barrier code:
• Use a shared counter protected by test-and-test-and-set lock. Each thread
locks the counter, increments it, releases the lock, and repeatedly reads
the counter until it reaches n.
• Use an n-element Boolean array A. Initially all entries are 0. When thread
0 executes its barrier, it sets b[0] to 1, and repeatedly reads b[n - 1]
until it becomes 1. Every other thread i, repeatedly reads b[i - 1] until
it becomes 1, then it sets b[i] to 1, and repeatedly reads b[n - 1] until
it becomes 1.
Implement both these schemes in Java. Each of the methods foo() and
bar() just sleeps for 20 milliseconds. Test the two schemes for n = 16. Run
each scheme at least ten times, measure the total runtime in each test run,
discard the highest and lowest values, take the average, and use it to compare
the two schemes. Which performs better? Can you explain the reason? You
can run the experiments on ecen5033.colorado.edu. Submit the code as well as
experimental results.

Related Discussions:- Concurrent Programming

Develop a simple polling web application , Develop a simple polling (voting...

Develop a simple polling (voting) web application according to the following specifications: 1. Initially a page should be presented to the user where he can enter his/her

Add wordpress color picker to plug-in text field, Add WordPress color picke...

Add WordPress color picker to plug-in text field Project Description: I have a simple plug-in that needs the built-in Word Press color picker added to one of the text input f

Android apk for 3g dongles support, ANDROID APK for 3G dongles support P...

ANDROID APK for 3G dongles support Project Description: We want someone who will modify this Android app or code a similar one. The App function is to let Android tablet P

What are the core classes of the struts framework, Struts is a set of coope...

Struts is a set of cooperating classes, servlets, and JSP tags that make up a reusable MVC 2 design. ? JavaBeans components for managing application state and behavior. ? Eve

Java graphic application, I need to draw cars and trucks and background wit...

I need to draw cars and trucks and background with road and a house with sky. I have to use Vehicle class as a parent class. To draw pictures, i should draw fun things coming up

What is actionform, An ActionForm is a JavaBean that extends org.apache.str...

An ActionForm is a JavaBean that extends org.apache.struts.action.ActionForm.  ActionForm handles the session state for web application and the ActionForm object is automatically p

What is an intelligent system, What is an intelligent system? Intellige...

What is an intelligent system? Intelligent system is a SW programs or SW and HW systems designed to perform complex tasks employing strategies in which mimic some aspect of hum

Bookshelves, Ask question #MBookshelves A library decides buy bookshelves t...

Ask question #MBookshelves A library decides buy bookshelves to store its books and they need to determine the bookshelves’ heights and widths in order to minimize storage costs. T

Difference between hashmap and hash table, Difference between HashMap and H...

Difference between HashMap and Hash table HashMap: It allow us to have null values and also one null key It is Unsynchronized. Iterator in HashMap is Fail-Safe.

What is documentation for the class library, What is Documentation for the ...

What is Documentation for the class library Sun gives a large amount of documentation for the classes, interface's and exceptions in the class library. If you've installed the

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd