epollkqueue

epollkqueue is a portable event notification abstraction that unifies the Linux epoll API and the BSD/macOS kqueue API under a single interface. It is intended for cross-platform event loops, allowing developers to write platform-agnostic code without many conditional compilations.

The library provides a common registration model to add, modify, and remove interest in a file descriptor's readability and writability, along with optional user data. At runtime it selects the appropriate backend: epoll on Linux, or kqueue on BSD/macOS. Internally it translates the platform-specific event representations into a unified event structure and exposes a single wait function with a timeout, returning the set of fired events. The wrapper also normalizes semantics such as edge-triggered versus level-triggered notification, offering a policy or explicit flags to align behavior across platforms.

Performance and limitations: While designed to be lightweight, epollkqueue cannot eliminate all platform differences, and subtle semantics (such as edge- versus level-trigger behavior and signal interaction) may require application-level adjustments. The abstraction may introduce small overhead compared to hand-tuned backends.

Usage and ecosystem: The API is typically adopted by asynchronous runtimes and network libraries that target multiple operating systems, reducing maintenance cost and conditional compilation. It is complementary to other cross-platform event loops and can be extended to include additional backends in the future.

See also: epoll, kqueue, select, poll.