What is the difference between Hard and Soft real-time systems?

Correct Answer: Micro-kernal : A micro-kernel is a minimal operating system that performs only the essential functions of an operating system All other operating system functions are performed by system processes Monolithic : A monolithic operating system is one where all operating system code is in a single executable image and all operating system code runs in system mode

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

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

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

Correct Answer: Hardware device that maps virtual to physical address In MMU scheme, the value in the relocation register is added to every address generated by a user process at the time it is sent to memory ->The user program deals with logical addresses; it never sees the real physical addresses

Correct Answer: Hard disk is the secondary storage device, which holds the data in bulk, and it holds the data on the magnetic medium of the diskHard disks have a hard platter that holds the magnetic medium, the magnetic medium can be easily erased and rewritten, and a typical desktop machine will have a hard disk with a capacity of between 10 and 40 gigabytes Data is stored onto the disk in the form of files

Correct Answer: Dispatcher module gives control of the CPU to the process selected by the short-term scheduler; this involves: Switching context, Switching to user mode, Jumping to the proper location in the user program to restart that program, dispatch latency ââ?¬â?? time it takes for the dispatcher to stop one process and start another running

Correct Answer: 1 Mutual exclusion (where at least one resource is non-sharable) 2 Hold and wait (where a process holds one resource and waits for other resource) 3 No preemption (where the resources can?t be preempted) 4 Circular wait (where p[i] is waiting for p[j] to release a resource i= 1,2,?n j=if (i!=n) then i+1 else 1 )

Correct Answer: An interpreter reads one instruction at a time and carries out the actions implied by that instruction It does not perform any translation But a compiler translates the entire instructions