Operating Systems Questions

1. Increased speed and memory capacity of microprocessors together with the support for virtual memory and

2. Growth of client server computing

All the above listed are the components of Windows registry

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.

Getting the value of an environment variable is done by using `getenv()’. Setting the value of an environment variable is done by using `putenv()’

Free memory is maintained in linked lists, each of equal sized blocks. Any such block is of size 2^k. When some memory is required by a process, the block size of next higher order is chosen, and broken into two. Note that the two such pieces differ in address only in their kth bit. Such pieces are called buddies. When any used block is freed, the OS checks to see if its buddy is also free. If so, it is rejoined, and put into the original free-block linked-list.

Mutex is the short form for ‘Mutual Exclusion object’. A mutex allows multiple threads for sharing the same resource. The resource can be file. A mutex with a unique name is created at the time of starting a program. A mutex must be locked from other threads, when any thread that needs the resource. When the data is no longer used / needed, the mutex is set to unlock.

Placement algorithms determine where in available real-memory to load a program. Common methods are first-fit, next-fit, best-fit. Replacement algorithms are used when memory is full, and one process (or part of a process) needs to be swapped out to accommodate a new program. The replacement algorithm determines which are the partitions to be swapped out.

- Network redirector/ Server

- Cache manager.

- File systems

- Network driver

- Device driver