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.


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

Code, Alia is appearing for the board exams. In order to qualify for the ne...

Alia is appearing for the board exams. In order to qualify for the next class Alia need to get exactly X credits. In current semester Alia has to study N number of subjects, and ev

What are access specifiers available in java, What are Access Specifiers av...

What are Access Specifiers available in Java? Java has four access specifiers, which are enlisted below: Public: public methods, classes and fields can be accessed by ever

Flash games, have some assignments and i want help with them. thanks

have some assignments and i want help with them. thanks

Explain what is fontmetrics in java, Explain what is FontMetrics in Java? ...

Explain what is FontMetrics in Java? No word wrapping is completed when you draw a string in an applet, even if you embed newlines in the string along with \n. If you expect th

Student, what are Objects and Fields in java

what are Objects and Fields in java

Thread, what is join in java Thread

what is join in java Thread

Complete the specification of chatter, Tasks: Complete the specifica...

Tasks: Complete the specification of CHATTER, and specify ChatterLists. Implement these ADTs in Java with an abstract class Chatter and a class ChatterList. Use javado

Write a java program in a netbeans project, Write a Java program in a NetBe...

Write a Java program in a NetBeans project that reads a text file containing the names and addresses of several people and displays them all at once or one at a time upon selecting

Why you don''t need to import java.lang.*, Why You don't need to import jav...

Why You don't need to import java.lang.* There is one exception to the import rule. All classes in the java.lang package are imported by default. Therefore you do not required

Which are three elements of event handler, The event handler attribute cons...

The event handler attribute consists of three elements. Write about each of them? 1. The identifier of the event handler. 2. The equal sign. 3. A string consisting of JavaScrip

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