7. Connections and state

7.1 Cables

An input holds up to 8 connections. Each is (source UID, output name, amount). Its value is the sum over connections whose source exists of sample × amount. The amount is a finite float, clamped to ±1000.

Any process MAY add, change or remove a cable into any registered input (this is how a patchbay in one plugin window edits another plugin), under the registry lock:

• Add: seqlock odd, fill a free connection, state = 1, seqlock even.
• Change amount of an existing cable: atomic store of amount_bits only; no seqlock.
• Remove: seqlock odd, zero the connection, seqlock even.
• After any of these: increment the owner's patch_version and connection_generation.

A receiving plugin watches its patch_version and tells its host that its state changed, so the set is marked as modified.

7.2 Saved state

Cables belong to the receiving instance and are saved in its plugin state. The reference format is UTF-8 text, one cable per line, fields separated by a tab:

bleep-bus-connections 1
<input name>	<source uid: 16 lowercase hex digits>	<output name>	<amount>

The amount is written as [-]digits.digits (six fraction digits) and parsed without the C locale, so it is stable across user locales. Readers accept CRLF line ends, a missing final newline and +/- signs; lines naming inputs the endpoint does not have are ignored.

Loading replaces all cables of the endpoint's inputs and increments connection_generation, but not patch_version (loading is not an edit).