Sharing Memory
Communication can also expand an operating system's view of memory. Shared memory can take several forms, each expanding operating systems in different ways. One way to share memory is to have a large area of RAM accessible by multiple processors. In this situation, the processors probably also use caches to speed up access to recently manipulated data, but now this cached data needs to be flushed much more often, as it needs to be accessible to all computers in the environment. Unless caches...
Ntfs
The New Technology File System - otherwise known as NTFS - debuted with Microsoft Windows NT. It supports many innovations over the FAT16 system used by previous Microsoft Windows versions compression, filelevel security, larger partitions and RAID. In addition, NTFS supports encryption of file-system data. One of the main features of NTFS is exceptional fault tolerance, because it is a transactional file system. NTFS does away with the file-allocation table and completely changes the way...
Interprocess Communication
One can certainly consider the use of synchronization primitives as a form of communication between processes. Processes that are synchronized over semaphores do indeed communicate the need for mutual exclusion. Often, however, more information needs to be exchanged between processes and therefore a more complicated set of semantics is required. Interprocess communication IPC builds on the ideas developed for process synchronization but adds concepts of data transfer and more complex exchange...
Communications on Other Operating Systems
Symbian OS is a great example of the way that most other operating systems model communications. Figure 11.6 is a good way to depict the application of I O concepts to communications in other operating systems. Device drivers are the way operating systems tie physical communications-hardware devices into the system. Every device is different, but every device must eventually be presented in a standard way. This means that devices must speak to the operating system via some kind of 'translator',...
Processes Threads and Active Objects in Symbian OS
Symbian OS favors threads and is built around the thread concept. A process is seen by the operating system as a collection of threads with a PCB and memory space. Thread support in Symbian OS is based in the nanokernel with nanothreads. Recall that the nanokernel is the basic, lowest level of the kernel. It provides very simple thread support in the form of nanothreads. The nanokernel provides for nanothread-scheduling, synchronization communication between threads and timing services....