Answer Happy

7. (a) In the inter-process communication context in an operating system, briefly explain Peterson's algorithm in handling race conditions. (6 marks) (b) What is the definition of virtual memory in the operating system context? (2 marks) (c) The following table shows the physical memory locations of four processes in a multitasking system. It uses the "segmentation" technique to map between virtual memory and physical memory. Physical memory address Process name Ox2300 Passbook Ox2800 Jump Game Ox5000 SolarManager OxF200 Airpolution.exe Note: the physical memory address is in hexadecimal. (1) What is the physical memory location of the virtual memory location 0x0316 of process Passbook? (ii) What is the virtual memory location of the physical address 0x5900 for SolarManager? (4 marks) (d) The Bitmap method is adapted by a file system for tracking free blocks on a disk. After the disk partition is formatted, a free space bitmap with sixteen blocks looks like this: 1000 0000 0000 0000 (the first block is used by the root directory). After writing file A, which uses 2 blocks, the bitmap looks like this: 1110 0000 0000 0000. Show the bitmap after each of the following operations: (1) File B is written, using 4 blocks (ii) File A is deleted (iii) File C is written, using 10 blocks (iv) File B is deleted (8 marks)