The com.io7m.jpuddle package implements a very simple object pooling system.

Object pooling is a programming technique where instead of creating new objects to service requests, a small pool of objects is created and the objects within the pool are reused repeatedly to service requests instead. This was traditionally used by Java programs as a performance optimization in an attempt to reduce memory allocations and therefore reduce the amount of garbage collection that occurs. On modern Java virtual machines, however, object pooling as a means to improve performance in this manner is strongly contraindicated: Object allocations are extremely fast (on the order of a few tens of nanoseconds), escape analysis often eliminates allocations entirely, and modern garbage collectors are optimized to make short-lived objects essentially free.

With this in mind, it may not be clear why the com.io7m.jpuddle package should exist at all! The answer is that object pooling is still useful when the objects represent external resources that may be very expensive to acquire and/or the program should avoid acquiring too many of these resources at any given time. An example of this sort of use case is allocating short-lived framebuffer objects [0] on a GPU. Graphics memory is typically in relatively short supply and creating an object on the GPU is generally considered to be an expensive and slow process (relative to simply allocating an object on the CPU side). A pool of framebuffer objects can be created that the application can reuse repeatedly without needing to create new objects, and the size of the pool can be bounded so that the application does not try to exceed the available GPU memory.

The project can be compiled and installed with Maven:

$ mvn -C clean install

Regular releases are made to the Central Repository, so it's possible to use the com.io7m.jpuddle package in your projects with the following Maven dependency:

<dependency>
  <groupId>com.io7m.jpuddle</groupId>
  <artifactId>com.io7m.jpuddle-core</artifactId>
  <version>0.5.0-SNAPSHOT</version>
</dependency>

All io7m.com packages use Semantic Versioning [1], which implies that it is always safe to use version ranges with an exclusive upper bound equal to the next major version - the API of the package will not change in a backwards-incompatible manner before the next major version.