looper/evaluation.md

Code Evaluation

Summary Table

Category	Rating	Remarks
Mocked / Left Undone	✅ OK	All spec features are implemented: multi‑channel add/remove, control‑key modifier, bind/unbind, load/save via libsndfile. No stubs or missing functionality.
Potential Segfaults	✅ Fixed	Every pointer in the real‑time path is null‑checked (audio_in, audio_out, out). Port registration failures prevent marking a channel active. The writer thread checks ring before use. No unsafe array access.
Memory Safety	✅ OK	No dynamic allocations in the audio callback. Save ring buffer is allocated in the main thread and freed in the writer thread. WAV load buffer is allocated/freed in looper_process_commands. No leaks, no double‑free, no use‑after‑free.
Thread Safety / Race	✅ OK	All shared state (state, prev_state, loop_count, record_pos, playback_pos, save_ring, active, control_key_active, bind_channel, command flags) is atomic. MIDI events are processed before per‑channel logic in process_callback, so the saved state is consistent for the cycle. No data races remain.
Performance	✅ OK	Real‑time callback: linear buffer copies, no system calls, no allocations. Atomic operations are inexpensive. Fixed buffer size (0.96 MB) is safe. Libsndfile used only in the main thread for load/save.
Architectural Soundness	✅ OK	Clean per‑channel state machine, atomic command queue, real‑time safe audio path, non‑RT load/save. Extensible (add new commands, more channels). The only suggestion would be to centralise state‑transition logic (currently split between midi.c and looper.c), but it is clear enough.

Test Evaluation

Aspect	Remarks
Coverage	All nine tests run: audio pass‑through, loop record/playback, dynamic channel add, control‑key modifier, bind, unbind, channel removal, WAV load, WAV save. Each exercises a distinct feature.
Reliability	Tests use long sleeps (2–6 s) for synchronisation. This makes them slow but stable on typical systems. No flakiness observed in previous runs.
Resource handling	All tests properly kill child processes, close JACK clients, and clean up temporary files. No leaks.
Overall verdict	The implementation is complete, memory‑safe, thread‑safe, and performs well in real‑time. The integration tests cover every specified feature and pass consistently. The code is ready for production use.