Configuration

When defining the bus type

Choose the event type, producer mode, fixed handler list, and publisher and consumer waiting strategies in EventBus(...). These choices determine the returned Zig type, so handlers cannot be added at runtime. To pass context to a callback, carry a pointer in the event.

When initializing a bus

init argument	Valid values	Consequence
allocator	A valid allocator lasting through deinit()	Owns ring and bookkeeping allocations
buffer_size	Nonzero power of two, including 1	Number of reusable event slots
max_batch_size	1 through buffer_size inclusive	Upper bound on a handler’s contiguous callback slice

These arguments have no defaults. The first program uses capacity 64 and batch limit 8 to demonstrate the API. The batch limit need not be a power of two.

Larger capacity uses more memory and can absorb bursts before backpressure. Larger batches can reduce callback overhead, but a handler acknowledges its consumed prefix only when the callback returns. Waiting strategies affect CPU usage while waiting for capacity or publication. Measure the trade-offs using the benchmark methodology.

Configuration is independent of lifecycle ownership: the thread that initializes the bus owns startup and shutdown even if another thread is its sole publisher.