Prioriteettischeduling

Prioriteettischeduling, or priority scheduling, is an operating system scheduling algorithm where processes are assigned priorities, and the CPU is allocated to the process with the highest priority. If multiple processes share the same highest priority, a tie-breaking mechanism, such as first-come, first-served, is typically used. Priorities can be assigned either statically by the system administrator or dynamically based on certain criteria.

There are two main types of priority scheduling: preemptive and non-preemptive. In preemptive priority scheduling, if a new process arrives with a higher priority than the currently running process, the CPU is immediately switched to the new, higher-priority process. In non-preemptive priority scheduling, once a process starts executing, it continues until it completes or voluntarily releases the CPU, even if a higher-priority process arrives in the meantime.

A significant challenge with priority scheduling is the potential for starvation. Lower-priority processes may never get to execute if there is a continuous stream of higher-priority processes arriving. This issue can be mitigated through aging, a technique where the priority of a process is gradually increased over time, ensuring that eventually, even low-priority processes will gain access to the CPU. Priority scheduling is used in various systems, including real-time operating systems where timely execution of critical tasks is paramount.