Hi students, welcome back. Coming to the next topic in the subject, operating system is a real-time operating system. So, this is also one of the important concepts.
So far, you have seen so many different types of operating system and coming to the last type of operating system is a real-time operating system. So, by reading this name, what you are understanding, we are using these type of operating system in the real-time applications. So, some real-time applications, that means, whenever we are given the input, the...
we have to get the output very quickly. So input, whenever you're given the input, you have to receive the response immediately. Those you call it as a real time, means these type of response, you call it as a real time.
So in those applications, we are using a real time operating system. So let's have a look on this, what exactly the real time operating system is. A real time system is defined as a data processing system.
So it is, one of the concept it's a data processing system in which the time interval required to process and response to inputs is so small that it controls the environment that is what i said so whatever the input we are given it has to respond very quickly so the interval between the processing the input and output is very small is so small the response it should be very small so that it going to control the environment Suppose if you take your artificial intelligence like if you take the automatic car. So the automatic car it is already means without the driver. So whenever you are given the instructions it is going it will take you to the destination. So without the driver.
So there we are using the real time operating system. So here that it going to control the environment whenever we need to a person is coming means whenever it feels some sensor. With the help of the sensor, it feels something is going to be in front of the car. So it applies the brake automatically.
So if it doesn't apply in the real time, obviously the car is going to hit the person or something like a thing, anything. Okay, so the input and output response should be very small. The time interval required to process and response is very small.
So that it's going to control the environment. So I hope you understand what exactly the real time operating system is. Another example, you can take the traffic signals, the traffic signals. OK, so whenever the green light and red light and yellow light, everything is depends upon the real time operating system. OK, the time taken from input to output task is response time.
What exactly the response time? Response time means whenever I say something, if you respond immediately. So the time between I ask the question and you're replying.
So I'm asking the question and you're replying. So the time in between whatever it takes that you call it as a response time. The time taken from input to output task is response time. The real-time operating system responds to input immediately.
Immediately. So whenever it is responding immediately, then you call it as a real time. Here the task is completed within the specified time delay. In real-time situations like controlling the traffic signals or nuclear reactors or aircrafts, so in all these fields, we are using this real-time operating system. So, which is going to control the traffic signals in the real-life situations.
If you use a nuclear reactor or if you use an aircraft, everything should be responsive in a real-time application. So, the input and output... It's a response time of input and output should be very small. It should be respond immediately. Whenever you are given the input, it has to respond immediately.
The operating system has to respond quickly. A system is said to be real-time if it is required to complete its work and deliver its service on time. Okay, so this is exactly the definition of the real-time. A system is said to be real-time if it is required to complete its work. and deliver its service on time like the flight control system so the flight control system whenever you are operating the flight control means it has to respond whenever the input is given okay otherwise the flight we may crash let's have a look on the types of real-time systems actually there are two different types of real-time systems one is the hard real time and one is a soft real time okay so what is a hard real time and what is a ha soft real time let's have a look on this the hard real time system is purely deterministic and time constrained system so here uh what exactly the hard real time system means it is purely deterministic means uh and some time constraint system should be there so within that uh a many time time it has to respond quickly it's purely deterministic okay uh like missile launching system satellite system airbag controls in car so everything should be respond immediately airbag controls in car how it is going to be whenever the car is going to kick something it's a very hard if you keep the seat belt it's automatically within a seconds it has to open the airbag control okay airbags has to be controlled in a car whenever something is going to be hit hardly okay that is a hard real-time system mean it has to be performed immediately means without any delay it's a missile launching system is also like that whenever you just click on that missile launching it has to be go and it has to be crack okay just like a satellite system so these are all you call it as a hard real-time system then what about the soft real-time system maybe it has some delay should be avoidable means means acceptable not avoidable whereas in hard real system you are not acceptable the delays but in the soft real time system it seems to be very soft that means in soft real time system the meeting of deadline is not compulsory this is the what i am talking about the small soft real time system means the meeting of the deadline is not compulsory for every time for every task but process should get processed it at a given and gives the result so anyhow it gives the result but there is not compulsory it has to meet the deadline means within this time it has to be completed there is no that much of uh criteria in the soft real time that's why we call the name itself is a soft soft means it has to take some time to complete the work okay but the task is it has to complete the process and gives the result I want the result, but I am not giving any deadline to that.
Okay, so anyhow, but not taking a lot of time because it is a real time, but it is not taking a lot of time, but it gives the result. That's why it is called as a soft real-time system. The examples for the soft real-time system is the personal computers, audio and video system, etc. Now, let's have a look on the characteristics of real-time operating system.
So, you have seen what exactly the real-time operating system is. And what is a hard real time system? Hard real time system means the one thing you have to remember that it has to respond very quickly. So there is no time delay should not be there.
So whenever you are supposed to do it has to do within a seconds. Okay, whereas soft means The meeting of the deadline is not compulsory in the soft real-time system, but the result has to be given. It has to give the result, but there is no deadline. Deadline is not compulsory for soft real-time system.
Characteristics of real-time operating system. Consistency, realability, predictability, performance, scalability. So these are all the characteristics of the real-time operating system, whatever the application you are taking. So for all that, these are the characteristics. Now have a look on the functions of the real-time operating system.
The functions are a task management is there, scheduling is there, resource allocation is there and interrupt handling is also there. So these are all the functions that this real-time operating system can do. It can manage the task management capabilities there. Scheduling technology will be there.
Resource allocation and management is there. And the interrupt handling, whenever the interrupts occur, it is going to handle by this real-time. operating system. So I hope you understand what exactly the real-time operating system is. Thank you.