TickBarrier

A spin-wait barrier used by SyncPolicy event buses to ensure all subscribers finish processing a tick before the publisher continues.

class TickBarrier {
public:
  explicit TickBarrier(std::size_t total);

  void complete(); // subscriber calls when done
  void wait();     // publisher blocks until all done
};

Purpose

Synchronise PUSH subscriber threads with the publisher in deterministic (back-test) mode, guaranteeing that no new events are published until the previous tick has been fully processed.

Behaviour

• Constructor stores _total = number of expected complete() calls.
• Each subscriber invokes complete() at the end of its tick loop.
• Publisher calls wait(); it busy-waits with std::this_thread::yield() until _completed == _total.

Notes

• Relies on std::atomic<size_t> with acquire/release semantics; no locks.
• Intended for low-thread-count scenarios; for large counts consider a futex or condition variable.