Resource allocation (computer)

Resource allocation, in the context of computer science and operating systems, refers to the process of assigning available computer resources to various processes, tasks, and applications. These resources can be hardware components, such as CPU time, memory space (RAM), storage space (disk), network bandwidth, peripheral devices (printers, scanners), and input/output (I/O) channels. They also encompass software resources like file handles, database connections, and semaphores.

The primary goal of resource allocation is to ensure efficient and fair utilization of these resources to optimize system performance, prevent resource contention (e.g., deadlock), and meet the demands of competing processes. Effective resource allocation contributes to improved system throughput, reduced response times, and enhanced user experience.

Resource allocation is managed by the operating system or specialized resource management software. It typically involves several key functions:

• Resource tracking: Maintaining an inventory of available resources and their current status (free, allocated, requested).
• Resource request handling: Receiving and processing requests from processes or applications for specific resources.
• Allocation policy: Implementing algorithms and strategies to determine which process receives which resource and when. Common allocation policies include First-Come, First-Served (FCFS), Shortest Job First (SJF), Priority Scheduling, and Round Robin.
• Deallocation: Releasing resources back to the system pool when they are no longer needed by the process that was using them.
• Resource protection: Preventing unauthorized access to resources and ensuring that processes only use the resources they are allocated.

Different resource allocation strategies are employed depending on the type of resource and the system's requirements. Some resources, like CPU time, can be preemptively allocated, meaning the operating system can interrupt a running process and reallocate the CPU to another process. Other resources, like printers, are typically allocated non-preemptively, meaning a process retains the resource until it voluntarily releases it.

Poor resource allocation can lead to several problems:

• Deadlock: A situation where two or more processes are blocked indefinitely, each waiting for a resource held by another.
• Starvation: A situation where a process is repeatedly denied access to a resource, even though it is continuously requesting it.
• Inefficiency: Underutilization of resources or excessive overhead due to inefficient allocation algorithms.

Therefore, careful design and implementation of resource allocation mechanisms are crucial for building robust and efficient computer systems.