itempool

An itempool, or item pool, is a collection designed to manage a set of items that can be borrowed, used, and returned for reuse. In software engineering, an item pool is often implemented as an object pool: a pool of pre-instantiated objects that are allocated once and reused to avoid repeated allocations and garbage collection. Each item in the pool is either idle or in use. When a caller needs an item, it requests one from the pool; when finished, it returns it for future reuse.

In game development, item pools manage frequently created and destroyed objects such as projectiles, particles, or pickups, improving performance by avoiding frequent allocations and deallocations during gameplay. In data processing or batch workloads, an item pool can refer to a collection of data units to be processed, where workers borrow items to operate on and then release them.

Implementation notes commonly involve storing items in a contiguous container, with a separate structure that tracks available indices (for example, a stack of free slots). Pools can be fixed-size or dynamically resizable. Thread-safety is a consideration for concurrent pools, and many designs include a reset or reinitialization step to ensure a clean state when an item is reused.

Advantages of item pools include lower latency, reduced garbage collection pressure, and improved memory locality. Drawbacks include higher and sometimes unused memory consumption, added complexity, and the risk of leaks or stale state if items are not properly released or reset. See also: object pool, resource pool, pool design pattern.