- Operating System Process Management
is an integral part of any modern day operating system (OS). The OS must allocate resources to processes, enable processes to share and exchange information, protect the resources of each process from other processes and enable synchronisation among processes. To meet these requirements, the OS must maintain a data structure for each process, which describes the state and resource ownership of that process, and which enables the OS to exert control over each process.
- Main Memory Management
Memory management is the act of managing computer memory. In its simpler forms, this involves providing ways to allocate portions of memory to programs at their request, and freeing it for reuse when no longer needed. The management of main memory is critical to the computer system.
Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the effectively available amount of RAM using disk swapping. The quality of the virtual memory manager can have a big impact on overall system performance.
Garbage collection is the automated allocation, and deallocation of computer memory resources for a program. This is generally implemented at the programming language level and is in opposition to manual memory management, the explicit allocation and deallocation of computer memory resources.
- File Management
A file manager or file browser is a computer program that provides a user interface to work with file systems. The most common operations used are create, open, edit, view, print, play, rename, move, copy, delete, attributes, properties, search/find, and permissions. Files are typically displayed in a hierarchy. Some file managers contain features inspired by web browsers, including forward and back navigational buttons.
Some file managers provide network connectivity such as FTP, NFS, SMB or WebDAV. This is achieved either by allowing the user to browse for a server, connect to it and access the server's file system like a local file system, or by providing its own full client implementations for file server protocols.
- I/O System Management
Input/output device information management system for multi-computer system
United States Patent 6526441
In a multi-computer system having a plurality of computers, an input/output device configuration definition table and an input/output device configuration reference table are adapted to be collectively managed. A configuration management program manages the configuration definition of all input/output devices of a plurality of computers by using the input/output device configuration definition table, and generates a changed data file when an input/output device configuration is changed. Dynamic system alteration is effected by changing the contents of the input/output device configuration reference table stored in a shared memory, in accordance with the changed data file. The input/output device configuration definition table and the input/output device configuration reference table each have an input/output device information part and an input/output device connection information part arranged in a matrix form to allow addition/deletion of an input/output device and a computer.
- Secondary Storage Management
Secondary storage management is a classical feature of database management systems. It is usually supported through a set of mechanisms. These include index management, data clustering, data buffering, access path selection and query optimization.
None of these is visible to the user: they are simply performance features. However, they are so critical in terms of performance that their absence will keep the system from performing some tasks (simply because they take too much time). The important point is that they be invisible. The application programmer should not have to write code to maintain indices, to allocate disk storage, or to move data between disk and main memory. Thus, there should be a clear independence between the logical and the physical level of the system.
- Protection System
With the new series of ThinkPads IBM introduced the Active Protection System (APS) in 2003. The APS is a protection system for the ThinkPad's internal harddrive. A sensor inside the ThinkPad recognizes when the notebook is accelerated. A software applet then is triggered to park the harddisk. This way the risk of data loss in case of when the notebook is dropped is significantly reduced since the read/write head of the harddrive is parked and hence can't crash onto the platter when the notebook drops onto the floor.
The hardware sensor is capable of not only recognizing acceleration of the notebook, but also (to a certain degree) of its whole orientation in space, relative to gravity's axis. Furthermore, having the actual control put into software, its functionality is extendable and it gives chance to implement features like the "ignore minor shocks" feature which is present in the Windows based control applet. (This feature prevents the harddrive from parking in case of minor regular shocks such as occur when in a train or car.)
The measurements are physically performed by an Analog Devices ADXL320 accelerometer chip, managed by the embedded controller.
- Command-Interpreter System
United States Patent 5931920
A hardware accelerated I/O data processing engine to execute a minimum number of types of I/O data processing commands in response to a stimulus from a host computer. The data processing engine, referred to as a command interpreter includes a command queue, a logic unit, a multiple purpose interface, at least one memory, and a controlling state machine, that each operate in concert with each other and without software control. The types of commands executed by the command interpreter can include, but are not limited to, an Initialize, Copy, DMA Read, DMA Write, Cumulative Exclusive OR, Verify, Compare, and ECC Check. The execution of commands that specify a source data location and a destination data location are characterized by a plurality of reads to an internal cache from the source data location for each bulk write from the internal cache to the destination data location. The locations of the data operated on by the command interpreter include a local I/O controller memory and a non-local I/O controller memory accessible to the command interpreter by way of an I/O bus.
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