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

We are in need of programmer, We are in need of Programmer In search of ...

We are in need of Programmer In search of someone who know java well enough to work under my in-house programmer and take work form him to keep the project moving. The project d

Cryptoarithmatic, Create problem that solves cryptoarithmatic problem that ...

Create problem that solves cryptoarithmatic problem that uses from user using java

Please help, please help please help please help please help please help pl...

please help please help please help please help please help please helpplease help please help

Program, Write a program called Power that displays the positive powers of ...

Write a program called Power that displays the positive powers of 2. When the user enters the exponent at a prompt, the program displays 2 to that power. The program halts when the

Explain identifiers in java, Explain Identifiers in Java ? Identifiers ...

Explain Identifiers in Java ? Identifiers are the names of variables, classes, methods, packages and interfaces. Unlike literals they are not the things themselves, only ways o

What is the difference between inner class and nested class, What is the di...

What is the difference between inner class and nested class? When a class is explained within a scope od another class, then it becomes inner class. If the access modifier o

Define the n-tier architecture or j2ee 3-tier?, Normal 0 false ...

Normal 0 false false false EN-US X-NONE X-NONE

Develop a java - jnlp application, Need Java/JNLP Application - GUI and Bac...

Need Java/JNLP Application - GUI and Backend Projects Project Description: I am looking for assistance in making changes to a complex java application. System launches fro

Minimum spanning tree based heuristic, Problem description: A travelling s...

Problem description: A travelling salesman wants to make a tour of the cities and returns back to the starting point. What is the minimum length tour? Formal Definiti

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