ES SEMINAR

2. OPERATING SYSTEM
An operating system is a software programme required
to manage and operate a computing device like
smartphones,tablets,computers,supercomputers,web
servers ,cars,network towers,smartwatches,etc.It is the
operating system that eliminatesssss the need to know
coding language to interact with computing devices.

3. “
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REAL TIME OPERATING SYSTEM
SET MAXIMUM TIME FOR PROCESS EXECUTION.
THE REAL-TIME OPERATING SYSTEM WHICH GUARANTEES THE
MAXIMUM TIME FOR CRITICAL OPERATIONS AND COMPLETE
THEM ON TIME ARE REFERED TO AS HARD REAL-TIME
OPERATING SYSTEMS.

4. 1.HARD REAL-TIME OPERATING SYSTEMS
2.SOFT REAL-TIME OPERATING SYSTEMS
RTOS TYPES

5. HARD REAL-TIME OPERATING SYSTEM
 Hard real time is a system whose operation is incorrect
whose result is not produce according to time constraint.
 In case of an error in a hard real time system,the
computation is rolled back.
For example,
1. Air traffic control
2. Medical system
3. Railway signaling system

6. SOFT REAL TIME OPERATING SYSTEM
 In this system safety is not critical .
 In case of an soft real time system,computation is
rolled back to previously established a checkpoint.
For example,
1. DVD player
2. Telephone switches

7. RTOS BASED EMBEDDED SYSTEM DESIGN
PRIORITY SCHEDULING
 PRE EMPTIVE SCHEDULING
 NON-PRE EMPTIVE SCHEDULING

8. PRE EMPTIVE SCHEDULING
A B
C
PERSON

9. NON - PRE EMPTIVE SCHEDULING
A B
C
PERSON

10. 1 . PRE EMPTIVE SCHEDULING
 Preemptive scheduling is used when a process switches from
the running state to ready state from the waiting state to
ready state .The resources are allocated to the process for a
limited amount of time and then taken away , and the process
is again placed back in the ready queue if that process stil
has CPU burst time remaining . That process stays in the
ready queue till it gets its next chance to execute .

11.  Algorithms based on preemptive scheduling are:
Round Robin (RR), shortest remaining Time (SRTF),
( priority (preemptive version ),etc.
Examples of preemptive scheduling

12. 2 . NON- PRE EMPTIVE SCHEDULING
 Non-preemptive scheduling is used when a prcess
terminates, or a process switches from running to the waiting
state.In this scheduling ,once the resources ( CPU cycles )
are allocated to a process holds the CPU till it gets terminated
or reaches a waiting state .In the case of non-preemptive
scheduling does not interrupt a process running CPU in the
middle of the execution . Instead , it waits till the process
completes its CPU burst time , and then it can allocate the
CPU to another process.

13. Examples of Non-preemptive scheduling
 Algorithms based on preemptive scheduling are:
shortest job first (SJF basically non-
preemptive).and priority (non-preemptive
version), etc.

14. Process Arrival time Burst time Priority
P1 2 2 2
P2 0 1 3
P3 1 3 4
P4 3 5 1
P5 4 4 5
Priority scheduling ( preemptive ) Example

15. Process Arrival time Burst time Priority
P1 2 2 2
P2 0 1 3
P3 1 3 4
P4 3 5 1
P5 4 4 5
Non-Priority scheduling ( preemptive ) Example

16. THANK YOU
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