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

How to convert string value to number in java, How to convert string value ...

How to convert string value to number in java? While processing user input it is frequent essential to convert a String in which the user enters into an int . The syntax is

Determine the phase loading- java program development, Determine the phase ...

Determine the phase Loading- Java Program Development In phase 3, the program must first be placed in memory before it can be executed. This is done by the class loader, whic

Write a program to find the area under the curve y = f(x) in, #question.Wri...

#question.Write a program to find the area under the curve y = f(x) in java.

What is the use of throws keyword, What is the use of throws keyword ? ...

What is the use of throws keyword ? Rather than explicitly catching an exception you can declare in which your method throws the exception. This passes the repsonsibility to h

Jdbc, creating connection which will authenciate for a password

creating connection which will authenciate for a password

Android Development Project, Task I have an Android mobile app project tha...

Task I have an Android mobile app project that I''m trying to get profiles to transfer by connecting to a server at 23.23.175.213 port 1337. I have to send a json string to the se

When should a method be static, When should a method be static? • Neith...

When should a method be static? • Neither reads from nor writes to example fields • Independent of the state of the object • Mathematical methods which accept arguments, appl

Dijkstra''s algorithm, How can I convert Dijkstra''s algorithm to do max fl...

How can I convert Dijkstra''s algorithm to do max flow instead of min flow, and how can I implement it into Ford Fulkerson algorithm?

The tic-tac-toe program, Instructions Modify the program so that the co...

Instructions Modify the program so that the computer will generate moves for the ‘O' player (it must continue to accept user input for ‘X'). A simple way to do this is to use a

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