Module collector 

Candle-powered rollout collector.

Connects CandleActorCritic directly to AsyncCollector so that policy inference runs in pure Rust — no Python calls during collection.

Architecture

┌─────────────────────────────────────────┐
│  Background Thread (pure Rust)          │
│                                         │
│  loop {                                 │
│    obs = VecEnv.step_all()     ~96μs    │
│    act = Candle.act(obs)       ~15μs    │  ← no Python dispatch
│    val = Candle.value(obs)     ~10μs    │
│    buffer.push(obs, act, val)           │
│    GAE = compute_gae_batched() ~5μs     │
│    channel.send(batch)                  │
│  }                                      │
└─────────────────────────────────────────┘
        ↕ crossbeam channel
┌─────────────────────────────────────────┐
│  Python Main Thread                     │
│                                         │
│  batch = collector.recv()               │
│  loss = ppo_loss(batch)    (PyTorch)    │
│  loss.backward()                        │
│  optimizer.step()                       │
│  collector.sync_weights(flat_params)    │
└─────────────────────────────────────────┘

Structs

SharedPolicy

Shared policy wrapper that allows the collection thread to read the policy while the main thread updates weights.

Functions

make_candle_callbacks

Build action_fn and value_fn closures that read from a shared policy.