# flare.runtime

> A module of flare_mlake's API.

``flare.runtime`` — event-loop primitives for the Stage 1 reactor.

Public exports, by area:

- Reactor: ``Reactor``, ``Event``, ``INTEREST_READ``,
  ``INTEREST_WRITE``, ``EVENT_READABLE``, ``EVENT_WRITABLE``,
  ``EVENT_ERROR``, ``EVENT_HUP``, ``WAKEUP_TOKEN``, ``LISTENER_TOKEN``.
- Scheduling: ``Scheduler``, ``Frontend``, ``TimerWheel``,
  ``num_cpus``, ``default_worker_count``, ``block_in_pool``.
- Buffers and memory: ``Pool``, ``BufferPool``, ``BufferHandle``,
  ``IoVecBuf``, ``writev_buf``.
- Cross-worker handoff: ``HandoffQueue``, ``WorkerHandoffPool``,
  ``HandoffPolicy``.
- Misc: ``DateCache``, the io_uring block, and the time helpers.

Read the module source for the authoritative list; names here that are
not re-exported from this barrel carry no stability guarantee.

``Reactor`` wraps ``epoll`` (Linux) and ``kqueue`` (macOS) behind a uniform
API. Use it to build single-threaded servers that handle many concurrent
connections from one OS thread. See the module docstring on ``Reactor`` for
an end-to-end example.

For multicore servers, use ``HttpServer.serve(handler, num_workers=N)``
with ``N >= 2`` and size ``N`` with ``num_cpus()`` (total logical CPUs) or
``default_worker_count()`` (sensible default for IO-bound handlers).