This document discusses simulating the working of a printer using a queue data structure. It introduces queues and how they are used when multiple objects need to access a shared resource, like people waiting in line at a bank. It then describes how an operating system uses a print queue to hold the identities of processes wanting to use the printer, with the longest waiting process gaining access to the printer once the current print job is finished.

1. LAB AAT
Simulate the working of a printer using Queue
data structure
DSA LAB – 21CSL38A
PRAGATI BAIRAGI (1BY21IS107)
PRAMOD KUMAR (1BY21IS108)
PRATYUSH RAJ (1BY21IS115)
Under the guidance of:
Dr SHANTHI D L
Assistant professor,
2022-23
ODD Semester
Department of Information Science & Engineering
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2. Contents
• Introduction
• Detailed description of an application
• Results and discussion
• References
Department of Information Science & Engineering
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3. 3
INTRODUCTION
Queues are used when multiple objects wish to
use a ``resource,'' but only one object can use the
resource at a time. A real-life example of a queue
is the line of people who wait at the bank to
interact with a teller---one person deals with the
teller (the ``resource''), and the others order
themselves so that the person who has waited
the longest goes next

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The printer:
The OS uses a ``print queue'' to hold the identities
of the processes (executing user programs) that wish
to use the printer. Once a process starts using the
printer, it is allowed to continue until it is completely
finished. The other processes that wish to use the
printer must wait, and their IDs (and the address of
the file to print) are kept in the queue. When the
process using the printer finishes, the process kept
waiting longest in the queue is retrieved, and its
print job is started.