What are operating system services?

Correct Answer: The processes that are residing in the main memory and are ready and waiting to execute are kept on a list called the ready queue

Correct Answer: When a process enters the system it is placed in the job queue

Correct Answer: A binary semaphore is one, which takes only 0 and 1 as values They are used to implement mutual exclusion and synchronize concurrent processes

Correct Answer: SCSI - Small computer systems interface is a type of interface used for computer components such as hard drives, optical drives, scanners and tape drives It is a competing technology to standard IDE (Integrated Drive Electronics)

Correct Answer: Distributed systems work in a network They can share the network resources,communicate with each other

Correct Answer: Scheduling is the activity of the deciding when process will receive the resources they request FCS ---> FCSFS stands for First Come First Served In FCFS the job that has been waiting the longest is served next Round Robin Scheduling--->Round Robin scheduling is a scheduling method where each process gets a small quantity of time to run and then it is preempted and the next process gets to run This is called time-sharing and gives the effect of all the processes running at the same time Shortest Job First ---> The Shortest job First scheduling algorithm is a nonpreemptive scheduling algorithm that chooses the job that will execute the shortest amount of time Priority Scheduling--->Priority scheduling is a scheduling method where at all times the highest priority process is assigned the resource

Correct Answer: A list of processes waiting for a particular I/O device is called device queue

Correct Answer: Data registers - can be assigned to a variety of functions by the programmer They can be used with any machine instruction that performs operations on data Address registers - contain main memory addresses of data and instructions or they contain a portion of the address that is used in the calculation of the complete addresses

Correct Answer: Mutual exclusion Hold and wait No preemption Circular wait

Correct Answer: When a process requests an available resource, system must decide if immediate allocation leaves the system in a safe state System is in safe state if there exists a safe sequence of all processes Deadlock Avoidance : ensure that a system will never enter an unsafe state