LRU Cache with Request Management

This implements an LRU cache for a I/O resource. On a cache miss, the cache requests the resource, blocking until it is available. The cache has the property that if multiple requests are concurrently made for a resource that is not in the cache, then only one request for the resource is made, and all requests block until it is available.

Because this library is designed for caching resources that require an I/O to fetch, it is fully concurrent. Fetches are made without holding any locks, meaning that:

1. While one operation is blocking due to a cache miss, additional operations on the cache will not block.
2. Multiple fetches for resources can be concurrently pending.

This library is also context-aware.

License

This library is licensed under the BSD 3-Clause License, but can also be licensed under the GNU GPL v3 License and freely used in projects licensed as GNU GPL v3.