introduction to advanced os
TRANSCRIPT
-
7/31/2019 Introduction to advanced OS
1/27
Advanced Operating Systems
PG-CSE1-02AGENDA
NEED FOR ADVANCED OS
OVERVIEW OF TYPES OF ADVANCED OPERATING
SYSTEMS
REVIEW OF PROCESS SYNCHRONIZATION
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
2/27
NEED FOR ADVANCED OS
Traditional OS ran on stand-alone computers
with single processors.
Considerable advances in Integrated Circuit andcomputer communication technologies led to
unprecedented interest in multicomputer systems
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
3/27
NEED FOR ADVANCED OS
Variety of computer architectures ranging from
shared memory multiprocessors to distributed
memory distributed systems were introduced.These multicomputer systems were prompted by
the need for high-speed computing that
conventional single processor systems wereunable to provide.
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
4/27
NEED FOR ADVANCED OS
The design of operating systems for these
multiprocessor and distributed systems becomes
very complex and difficult since there are manyidiosyncrasies associated with these systems
which are not present in traditional single
processor systems.
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
5/27
NEED FOR ADVANCED OS
Due to their relative newness and enormous
design complexity, operating systems for thesemulticomputers are referred to as Advanced or
Modern operating systems.
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
6/27
NEED FOR ADVANCED OS
An advanced operating system not only
harnesses the power of a multicomputer system
but also provides a high level coherent view ofthe system.
Due to advanced OS, a user views a
multicomputer system as a single monolithicpowerful machine.
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
7/27
NEED FOR ADVANCED OS
TYPES OF ADVANCED OPERATING SYSTEMS
Advanced operating systems
Architecture driven Application driven
Distributed OS Multiprocessor OS Database OS Real-time OS
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
8/27
NEED FOR ADVANCED OS
The design of advanced operating systems has
been driven by the following factors :
Advances in the architecture of multicomputersystems, evolution of wide variety of high-speed
architectures.
Examples are multiprocessor systems anddistributed computing systems.
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
9/27
NEED FOR ADVANCED OS
Several important applications namely database
systems, real time systems , graphics systems,
surveillance, process control etc. require specialoperating system support for efficiency which
cannot be provided by general purpose OS.
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
10/27
Distributed Operating Systems
Distributed OS are the OS for a network of
autonomous computers connected by a
communication network
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
11/27
Distributed Operating Systems
Distributed OS controls and manages the
hardware and software resources of distributed
system and provides the view of the entire systemas a monolithic computer system
When a program is executed in a distributed
system, the user is not aware of where theprogram is executed or of the location of the
resources accessed
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
12/27
Basic design issues of a distributed OS
Process synchronization
Deadlocks
Scheduling
File Systems
Inter process communication
Memory and buffer management
Failure recovery etc.
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
13/27
Idiosyncrasies of a distributed systems
Lack of both shared memory and a physical
global clock
Unpredictable communication delays
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
14/27
Multiprocessor Operating Systems
A multiprocessor system consists of a set of
processors that share a set of physical memory
blocks over an interconnection networkThus, it is a tightly coupled system where
processors share an address space
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
15/27
Multiprocessor Operating Systems
A multiprocessor OS controls and manages the
hardware and software resources such that users
view the entire system as a powerful uniprocessorsystem
A user is not aware of the presence of multiple
processors and the interconnection network
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
16/27
Basic design issues of a Multiprocessor
OS
Same as in a traditional operating system
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
17/27
Idiosyncrasies of a multiprocessor system
The issues of process synchronization , task
scheduling, memory management and protection
and security become more complex because themain memory is shared by many physical
processors
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
18/27
Database Operating Systems
A database operating system must support :
the concept of transaction
operations to store, retrieve and manipulate alarge volume of data efficiently
primitives for concurrency control
system failure recovery
buffer management scheme for storingtemporary data and data retrieved fromsecondary storage
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
19/27
Idiosyncrasies of a database operating system
Concurrency control is the most challenging
problem in the design of the database operatingsystem
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
20/27
Real-time Operating Systems
Jobs have completion deadlines in RTOS
A job should be completed before its deadline to
be of use(in soft real-time systems)
Or to avert a disaster (in hard real time systems)
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
21/27
Idiosyncrasies of a real-time operating
system
The major issue in the design of real time
operating systems is the scheduling of jobs in sucha way that a maximum number of jobs satisfy
their deadlines
The other issues include designing languages andprimitives to effectively prepare and execute a job
schedule
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
22/27
OVERVIEW OF PROCESS SYNCHRONIZATION
MECHANISMS
Process a program in execution means a programwhose execution has started but is yet not
complete
Basic states of a process running, ready, blocked
Running processor is executing the instructions of
the corresponding process
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
23/27
OVERVIEW OF PROCESS SYNCHRONIZATION
MECHANISMS
Ready- the process is ready to be executed, but
processor is not available for the execution of this
process
Blocked the process is waiting for an event to
occur e.g. I/O operation waiting to be completed,
memory to be made available, a message to bereceived etc.
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
24/27
OVERVIEW OF PROCESS SYNCHRONIZATION
MECHANISMS
A data structure called as PCB stores completeinformation about a process such as its ID, process
state, priority, privileges, virtual memory address
translation maps etc.Operations such as create, kill, signal, suspend,
schedule, change-priority, resume etc . can be
performed on process
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
25/27
Types of processes
Independent
Cooperating
Process synchronization is required when
processes interact with each other
Process synchronization is normally achieved by
regulating the flow of execution of a process
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
26/27
Types of processes
Concurrent and Serial processes
Two processes are concurrent if their execution
can overlap in time i.e. if the execution of the
second process starts before the first processcompletes.
Two processes are serial if the execution of one
must be completed before the execution of theother can start.
Dr.Manali Kshirsagar,YCCE,Nagpur
-
7/31/2019 Introduction to advanced OS
27/27
Types of processes
Concurrent processes generally interact througheither of the following mechanisms :
Shared Variables : The processes access(read or
write) a common variable or common data.
Message Passing: The processes exchange
information with each other by sending and
receiving messages.
Dr.Manali Kshirsagar,YCCE,Nagpur