Resource management (computing)

In computer programming, resource management refers to techniques for managing resources (components with limited availability). It includes both preventing resource leaks (releasing a resource when a process has finished using it) and dealing with resource contention (when multiple processes wish to access a limited resource). Resource leaks are an issue in sequential computing, while resource contention is an issue in concurrent computing. This article discusses preventing resource leaks; see resource contention for resource management in that sense.Memory can be treated as a resource, but memory management is usually considered separately, primarily because memory allocation and deallocation is significantly more frequent than acquisition and release of other resources, such as file handles.Computer programs may manage their own resources, and there are various techniques for resource management, depending on the programming language; Elder, Jackson & Liblit (2008) is a survey article contrasting different approaches. Alternatively, they can be managed by a host – an operating system or virtual machine – or another program. This is known as resource tracking, and consists of cleaning up resource leaks: terminating access to resources that have been acquired but not released after use. This is known as reclaiming resources, and is analogous to garbage collection for memory. On many systems the operating system reclaims resources after the process makes the exit system call.A key distinction in resource management within a program is between stack management and heap management – whether a resource can be handled like a stack variable (lifetime is restricted to a single stack frame, being acquired and released when execution enters and exits a particular scope), or whether a resource must be handled like a heap variable, such as a resource acquired within a function and then returned from it, which must then be released outside of the acquiring function. Stack management is a common use case, and is significantly easier to handle than heap management.