A pointer is a special type of data type. Instead of storing data, it stores a memory location. At this location is the data. In some languages, like C/C++, they expect the programmer to track and maintain the pointer information, using special references to know if they are storing/retrieving a location for data, or accessing…
A lot of native data types of date/time, numeric, and string fields don’t work when you try to model a lot of real world situations. They are good for a portion of the information, but not all. For example, if I wanted to store information about a player in a computer game, no one of…
A process creation hierarchy is a graphical representation of the dynamically changing parent-child relationships among all processes. The process creation hierarchy changes each time a process is created or destroyed. When a process initiates the creation of a child process, the OS executes a create process function. The create process function allocates a new PCB, fills the PCB entries…
CPU_state – When the process is stopped, the current state of the CPU, consisting of various hardware registers and flags, is saved in this field to be reloaded when the process resumes. PCB Data Description Data Stored As Can Change process_state This is the state of the process, running, ready, or blocked most often. Integer…
A process is an instance of a program being executed by an OS. The OS manages the processes in something called a Process Control Block (PCB). This helps it keep track of what is running, how much memory is being used and where, the program being run, the current instruction address, etc. Your operating system as a…
The modern OS is a complex structure comprised of millions of lines of code. Not all information is released, and is this core components, or everything including additional apps that have been included? Mac OS X Tiger (10.4) ~ 84 Million Lines of Code Windows Vista (2009) ~50 Million Lines of Code Debian 7.0 (2012)…
Book chapter notes: The operating system (OS) is the software that runs on the bare hardware of a computer and provides essential support for users to develop and use applications in the most efficient and safe manner. The OS will also serve as an abstraction layer for the user/applications to interact with hardware. The OS can serve…
An array is not really a datatype, but a collection of variables, (usually) of the same type. However, arrays are handled differently in different languages. Sometimes they act as an object, and thus there is an Array Class, sometimes it is a pointer to memory, usually their size is static, but not always. Each language…
