Summary Blog Post | CPT304

    Features of contemporary operating systems include Process Management – manages the CPU and processes, I/O (Input/Output) Management – manages devices, File Management – organizes and keeps track of files and directories, Memory Management – allocates/deallocates memory space and keeps track, Security and Protection – users, process, devices, have their own access to their own stuff, Accounting – keeps track of all resources. This is all wrapped up behind the User-Interface (UI), which makes it easier for the user to interact with the computer and its resources – I/O devices, files, memory, CPU.

    A program in execution, that is active and loaded into memory, is known as a process, or job (Silberschatz, Galvin, & Gagne, 2014). The textbook makes a point to distinguish a program as passive, sitting on a disk, and active, executing its instructions and thus a process. Processes can share exchange information due to multi-threading, as this allows for the task to split up, sharing resources, and get completed faster, which terminates the process faster.

    Main memory and virtual memory are tied to one another to better manage memory. Physical Addresses pertain to the actual registers of main memory, also known as real address, though they are never seen by the user and are limited to what is available. This is tied to the virtual/logical addresses through to the memory management unit and does not change. Virtual Addresses, also known as logical addressed, pertains to the address that the CPU generated for a process. This kind of address isn't technically real, so it’s unlimited. It’s more of a pointer from the CPU so it when it can access the memory. This is seen by the user and does change as it needs to be mapped to a physical address for it to be functional.

   In a modern computer system, files are managed by the file management system. As users we know this to be the file explorer icon that’s usually located on the lower left by the start icon. Here we can navigate all the files on the computer, we can search, see their properties, edit, copy, move, create, download, upload, and encrypt. I/O devices are managed by the Device management system, keeping track of all devices that are connected to the computer in some shape or form, and the drivers needed to connect. Both systems contribute to mass storage, ensuring that the programs and files are stored on the disk when not in use, thus freeing up main memory and allowing more efficient performance, or brought up to main memory when needed.

    One of the mechanisms necessary to control the access of programs or resources is known as the access matrix, which ensures that access and rules are assigned accordingly, maintained, and enforced as this is only managed by authorized admins. Each object (resource, hardware, software) also has an Access Control List, specifying what user/process/item has access to that object. Another mechanism, called a capability, allows request to a resource to “point” to it instead of directly asking for access. This provides another level of protection of resources.

    Knowing these concepts allows me to see things with a more perspective, not just as I seek out a position in the IT field. In a personal sense, it helps to know how memory works in relation to my files and apps and I/O devices and storage, so I can troubleshoot better. In my current workspace, it helps to know about access, protection and security when I or my co-workers are unable to install or do something. And in the IT role I intend to achieve, it helps to know that security can be implemented at compiler level, so I keep a better understanding of the language I have and intend to learn and grow.

See full concept map | Concept Map LG

Sources

Silberschatz, A., Galvin, P. B., & Gagne, G. (2014). Operating system concepts essentials (2nd ed.)