looper/evaluation.md

Code Evaluation

Summary Table

Category	Rating	Remarks
Mocked / Left Undone	✅ OK	Multi‑channel and dynamic channel add/remove are now implemented. Control key (note 64) is handled as a modifier for command selection. Backward compatibility for note 1, 60, 61 retained.
Potential Segfaults	✅ Fixed	Added null checks for both audio_in and audio_out in the process callback, and channel_add no longer marks the channel active if port registration fails.
Memory Safety	✅ OK	No dynamic memory allocation; only a fixed‑size global buffer. No leaks, no use‑after‑free.
Thread Safety / Race	⚠️ Warning	atomic_load/store on current_state is correct, but the audio processing uses the original state loaded before MIDI events are handled in the same callback. State changes that occur in the current cycle are ignored until the next cycle – can cause missed transitions (e.g., start recording one cycle late).
Performance	✅ OK	Linear buffer access, no system calls or allocations in the real‑time callback. Atomic operations are cheap. Fixed buffer size (0.96 MB) is safe.
Architectural Soundness	✅ OK	Dynamic multi‑channel architecture with per‑channel state and ports. Real‑time safe command queue via atomic flags. Abstraction via channel_t struct. Extensible for future binding.

Test Evaluation

Aspect	Remarks
test_audio_pass_through	Verifies basic audio connectivity; passes when JACK server running. Does not test any looper‑specific behavior beyond pass‑through.
test_looper_looping	Exercises the state machine (IDLE→RECORD→LOOPING) using MIDI note 1. Detects repeated audio bursts. Works with current implementation but uses note 1 instead of the required control key (64). The 0.1‑second beep and 4‑second wait may be sensitive to CPU load.
test_multiple_channels	Expects dynamic channel creation via note 60 (add channel). Current looper does not handle this command, causing immediate failure. This test is effectively a placeholder for future implementation.
Coverage gaps	No tests for: control key note 64, remove channel, binding, per‑channel loops, state transitions other than note 1, robust handling of JACK server disconnection.
Thread safety	The test assumes sequential execution and uses long sleeps for synchronization. The real‑time thread is managed by JACK; the test process runs asynchronously, which can lead to timing‑sensitive failures on heavily loaded systems.
Resource handling	Tests properly kill child process and close JACK clients. No memory leaks.
Overall verdict	The test suite provides a minimal smoke‑check but does not validate the full specification. It must be updated to use the correct control key (64), cover dynamic channel commands (add/remove/bind), and handle non‑existent features before it can be considered a trustworthy integration test.