Reference no: EM132294643

Practical Case Study

1 Introduction

In this case study you will implement a simple logging service built on top of a message queue.

2 Specification

The task is broken into three parts, a message logging server, a library to log messages, and a driver to test the library. You will need to review the lecture notes, and the documentation supplied in Section 5 to implement these programs.

Message Logging Server

The message logging server should attempt to create the message queue, if this fails then it should terminate with an error message, it should not run if the message queue actually exists (IPC_EXCL will help here).

Once connected to the message queue, the program should sit in a loop, receiving a mes-
sage, and printing it to the stdout. Messages should be formatted:
id: message
where id is the type from the message structure and message is the message field.

The server should shutdown cleanly (i.e. delete the message queue) on receipt of a SIGINT (generated by pressing control and C keys at the same time).

The sample code files logservice.h and logserver.c should form the basis of your solution for this part.

Messaging library
The messaging library consists of two functions, both defined in logservice.h:

int initLogService()

This function should initialise the message queue to log messages to, returning an id if successful, and -1 on error.
This function should not attempt to create the message queue, only attach it to the process.

int logMessage(int id, char *message)

This function logs the message passed as the string message to the log service id. It should return 0 on success and -1 on error.
When sending a message, the function should encode the processes pid into the type field of the message, and the string into the message field.

It is your choice what to do if the message is too long (i.e. longer than MSGCHARS), sample behaviours include breaking the message up into smaller pieces or simply rejecting it. Whatever the choice, the documentation in the header file should re2ect this choice.
The sample code files logservice.h and logservice.c should form the basis of your solution for this part.

Test Driver
This program is used to test the functionality of the library described in Section 2.2. It need not be complex, but is should be able to determine, and report if any errors have occurred.

The sample code files logservice.h and logclient.c should form the basis of your solution for this part.

Attachment:- Operating Systems Programming.rar