Debug the robot while it runs.

from omniloop import TrainingLoop

# Bind config attributes live & record to a trace
loop = TrainingLoop.from_dataclass(
    cfg.ppo,
    tunable=["learning_rate", "entropy_coef"],
    bind={"learning_rate": optimizer},
    journal="run.omni",
)

for epoch in range(num_epochs):
    with loop.tick():  # halt barrier & apply edits
        train_epoch()
        loop.log(loss=loss_val)  # publish telemetry

from omniloop import load_events, JournalPlayer

# Parse mutations, freezes, and watchpoint trips
for event in load_events("run.omni"):
    print(f"[{event.timestamp}ms] Tick {event.tick}: {event.kind} -> {event.detail}")

# Replay telemetry & events frame-by-frame
player = JournalPlayer("run.omni")
while record := player.read_next_record():
    if record.kind == "telemetry":
        apply_state(record.payload)

// omniloop-core/src/ipc.rs
pub struct TelemetrySeqlock {
    seq: AtomicU64,
    slot: UnsafeCell<[u8; SLOT_BYTES]>,
}

impl TelemetrySeqlock {
    /// Lock-free publish: writers never block the loop.
    pub fn publish(&self, frame: &[u8]) {
        let s = self.seq.fetch_add(1, Ordering::AcqRel);
        unsafe { (*self.slot.get())[..frame.len()]
            .copy_from_slice(frame); }
        self.seq.store(s + 2, Ordering::Release);
    }
}