Question

1. Give a brief definition for each of the following

A. Process

B. Process switch

C. GUI

D. Window manager

E. Interrupt handler

F. Ready process

G. Waiting process

H. shell

2. Summarize the booting procedure.
3. What are the 5 components of an OS’s kernel?

Summarize the role for each of them

4. What does CPU do when it receives an interrupt?
5. What information is contained in the state of a process?
6. If each time slice in a time sharing system is 40 milliseconds and each context switch (process switch) requires 1 microsecond, how many processes can the machine serve in a single second? If the machine executes an average of 10 instructions per nanosecond, how many instructions could be executed in a single time slice?

Answer 1

Answer:----------
A. Process :- A process is an active program. It can also be said as a program that is under execution. It is more than the program code as it includes the program counter, process stack, registers, program code etc. Compared to this, the program code is only the text section.

B. Process switch :- To control the execution of processes, the kernel must be able to suspend the execution of the process running on the CPU and resume the execution of some other process previously suspended. This activity goes variously by the names process switch , task switch , or context switch .

C. GUI :- A GUI (graphical user interface) is a system of interactive visual components for computer software. A GUI displays objects that convey information, and represent actions that can be taken by the user.

D. Window manager :- A Window Manager is the program responsible for coordinating all the the windows on the screen.The job of a window manager is to handle how all of the windows created by various applications that share the screen and who gets user input at any given time.

E. Interrupt handler :-
An interrupt handler is just a routine containing a sequence of operations. Each of these may request input and output while running. The interrupt handler has a set of responsibilities to perform. Some are required by the framework, and some are required by the device. All interrupt handlers are required to do the following:

• Determine if the device is interrupting and possibly reject the interrupt.
• Inform the device that it is being serviced.
• Perform any I/O request-related processing.
• Do any additional processing that could save another interrupt, for example, read the next data from the device.

F. Ready process :- The ready state of a process is "When process is scheduled to run after some execution." Reason: When process is started, it directly enters into the ready state, there it waits for the CPU to be assigned. The process which are ready for execution and resides in the main memory are called as ready state processes.

G. Waiting process :-
A Waiting process is a situation in which a computer program or processor is waiting for the completion of some event before resuming activity. A program or process in a wait state is inactive for the duration of the wait state.

H. shell :- A Shell provides you with an interface to the Unix system. It gathers input from you and executes programs based on that input. When a program finishes executing, it displays that program's output.

Q:- Summarize the booting procedure?
Answer:----
Booting starts the operating system we can say it is the very first thing/actiontakesplace as soon as we switch on computer system.
Booting a computer refers to the process of powering on the computer and starting the operating system. The operating system is the program that makes all your software applications and hardware work together, so you can do the work you want to do. Once you hit the power button, it's all automatic from there. The boot process loads the operating system into main memory or the random access memory (RAM) installed on your computer. Now let's learn a little more about the boot process.

Q:- What does CPU do when it receives an interrupt?
Answer:----
When a hardware interrupt occurs the CPU stops executing the instructions that it was executing and jumps to a location in memory which either contains the interrupt handling code or an instruction branching to the interrupt handling code.

Q:- What information is contained in the state of a process?
Answer:---
A table containing all the information that must be saved when the SPU switches from running one process to another in a multitasking system. Also contains outstanding I/O requests.