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Operating Systems One-month project


  • Learn to work with Nachos networking for communication among processes.
  • Define and implement a “chat” protocol for interaction between a chat server and a chat client.

Problem statement:

Chat rooms have become a popular way to support a forum for n-way conversation or discussion among a set of people with interest in a common topic. Chat applications range from simple, text-based ones to entire virtual worlds with exotic graphics. In this project you are required to implement a simple text-based chat client/server application.

Problem description:

Email, newsgroup and messaging applications provide means for communication among people but these are one-way mechanisms and they do not provide an easy way to carry on a real-time conversation or discussion with people involved. Chat room extends the one-way messaging concept to accommodate multi-way communication among a set of people.

Nachos networking infrastructure

Nachos networking packages implements a very simple Unix domain (not internet domain), datagram socket. The files of importance to this project and their purpose are described below.

threads directory:

lockcond.h, lockcond.cc: for defining and implementing lock and condition synchronization primitives; needed for network applications to work.

machine directory:

network.h, network.cc: Data structures to emulate a physical network connection. The network provides the abstraction of ordered, unreliable, fixed-size packet delivery to other machines on the network.You may note that the interface to the network is similar to the console device -- both are full duplex channels.

sysdep.h, sysdep.cc : Interprocess communication operations, for simulating the network; Unix sockets creation, binding, closing etc. are called here to provide nachos socket functionality.

network directory:

post.h, post.cc: postoffice and mailbox, mail message definition and implementation.

nettest.cc: application to test communication between host id 0 and host id 1 (these are hardcoded!)

Chat architecture:

A chat application consists of a Chat Client (CC) one per person, a Chat Server (CS) and a two-way communication pipeline between the client and the server to send and receive conversational, control and status messages.

  • Chat Client:

Typical features of a CC include: (i) select chat server (server id), (ii) select a nickname for interaction and (iii) ability to set and change user preferences such as number of messages displayed, change nickname, etc. You may design your own chat user interface.

Implementation notes:

The server id is specified at command line (nachos –rs 1234 –m selfid –o serverid ) while executing the nachos process representing the client.

Once the client process is running it could interactively ask the user for the nickname of the chat user and update this information locally and if needed by your design on the server.

  • Chat Server:

A chat server supports the set of clients for a room, by maintaining client handle (clientid in nachos –rs –m clientId –o serverid), and client name. Server also has a message interpreter that parses the message received from a client and delegates the command to the appropriate module. Sample architecture for the chat application is shown in Figure 2. You may change the architecture to suit your design.

Questions & Answers

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
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Source:  OpenStax, Operating systems. OpenStax CNX. Aug 13, 2009 Download for free at http://cnx.org/content/col10785/1.2
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