Threads

Layout

GUI thread
- editing (Actions)
- Observer messages
PeakThread
in/out signal chains having their own threads
- SongRenderer might become multi-threaded...
Observer messages from other threads must be forwarded via hui::run_later()

Locking

PeakThread locks Song (write,try)
MidiPreview locks self
ViewModeCapture.draw_post() locks Audio/MidiAccumulator.buf
PerformanceMonitor locks self
FFT locks planner
SignalChain...send-to-modules locks self
SongRenderer locks Song (read)
Audio/MidiAccumulator.suck() locks buf
hui::runner... locks self
Actions lock Song (write)
RingBuffer.clear() locks buf (....)
SongRenderer configuration (allow_layers set_pos etc) don't lock, instead they buffer the values and the locked read() will really update

Safety

??? Song.StructureReader

RingBuffer

safe for single consumer + single producer

False positives

OutputStream.paused
AudioSucker.running
RingBuffer
- reading/writing: locks before and after, but not during mem access still safe because of these locks

Observer

InputStreamAudio sends in main thread
InputStreamMidi sends in main thread (well, does not send at all...)
OutputStream sends in main thread, but needs to be controlled from main thread

new thoughts

Song owned by main thread -> can always read, needs to lock for writing (only through actions) ** other threads only allowed to read when locking. Can not directly edit