A fixed set of lock-free occurrence counters. More...

#include <activity_channel.hpp>

Public Types
using	Sequence = std::uint32_t

Public Member Functions
void	signal (std::size_t lane) noexcept
	Record activity on `lane`.
Sequence	sequence (std::size_t lane) const noexcept
	Read the current sequence for `lane`. Invalid lanes read as zero.
bool	consume (std::size_t lane, Sequence &cursor) const noexcept
	Return true once when activity has occurred since `cursor` was last consumed, updating the cursor to the newest sequence.
Sequence	consume_count (std::size_t lane, Sequence &cursor) const noexcept
	Return the number of signals since `cursor` and advance it to the newest sequence.

Static Public Member Functions
static constexpr std::size_t	lane_count () noexcept

Detailed Description

template<std::size_t LaneCount>
class pulp::runtime::ActivityChannel< LaneCount >

A fixed set of lock-free occurrence counters.

This channel is for payload-free occurrences whose complete meaning is "lane N was active": MIDI pad flashes, clipping indicators, manual trigger requests, and similar signals. Producers call signal() from either side; each consumer keeps one Sequence cursor per lane. consume() intentionally coalesces a burst into one observation, while consume_count() preserves the number of occurrences for command paths that must replay every trigger. signal() is multi-producer safe; consumers are independent because each owns its cursor.

The channel carries no associated payload, so relaxed atomic ordering is sufficient. It allocates nothing and takes no locks in signal(). Share the channel with a view through SharedActivityChannel so a host that retains an editor after destroying its Processor cannot leave the view polling freed processor memory. Sequence wrap is harmless for ordinary polling; only an exact multiple of 2^32 unconsumed signals can alias the cursor.