It is a software which acts as intermediate between user and hardware.
Batched operating System
Multi-Programming Operating System
Timesharing Operating System
Distribued Operating System
Real-Time Operating System
Resource management
Memory management
I/O management
Execution of programs
Security
When two processes are holding some resources and waiting for other resources,this result in both both process to hang
A program in execution in process
New
Running
Waiting
Ready
Terminated
Utilization of cpu
Increased throughput
these system have more then two processors which perform differnt operations together.
Real-Time systems send immediate response according to your input.
System programs provide a convenient envirorment for program execution and development.
System calls acts as interface between program and operating system which manages different resources.
. Virtual Machine enables user to create virtual resource allocation to run different os or other applications.
Program Status Word. it controls the order of execution and contains information about the status of the process.
it is an event that disturbs the sequence in which Processor executes instructions.
it is number of proceses in the memory, it is called stable when the average rate of number of process creation is equal to number of average process departure.
When a process do not get required resource for long time then this situation is called starvation.
Aging is a technique used to avoid starvation in systems.
Semaphore is type of variable whose status reports common resource
Binary Semaphore
Counting Semaphore
Binary Semaphore is Semaphore with an integer value that can range between 0 and 1
the process of taking cpu from one process and assigning cpu to other process is called context switching
it is technique in which system appears to have more memory that it actually does.
Thread is light-weight process, we split a process into multiple threads.
it is a state in virtual memory when the processor spends most of time in swapping pages then in executing the process.
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