Why: On Python 3.9/3.10, asyncio.Queue() and asyncio.Lock() bind to
the running event loop at construction time. If the SDK is instantiated
from a synchronous factory before an event loop exists, both primitives
raise "RuntimeError: ... is bound to a different event loop" on first
use. Fix: EventDispatcher defers Queue creation to start(), with a
guard in dispatch() that raises RuntimeError if called before start().
CommandHandlerBase defers Lock creation via a lazy @property accessor.
Both document the contract change in class docstrings.
Refs: Forensics report finding F08
Why: EventDispatcher._process_events() calls task_done() on the queue
immediately after spawning async callback tasks. await queue.join() in
stop() therefore returns as soon as all items are marked done, even if
their async callbacks are still executing. Any caller that does
"await dispatcher.stop(); cleanup()" could race with still-running
callbacks. Fix: after queue.join(), gather all tracked background tasks
before cancelling the dispatch loop.
Refs: Forensics report finding F07
Why: Python's asyncio holds only weak references to tasks created via
create_task(). Under GC pressure (especially Python < 3.11), unretained
tasks can be silently cancelled mid-execution, and any exceptions are
swallowed as "Task exception was never retrieved." Seven call sites
across TCPConnection, BLEConnection, SerialConnection, and
EventDispatcher used fire-and-forget create_task with no stored
reference. Fix: introduce _background_tasks set and _spawn_background()
helper on each class, following the standard pattern from the asyncio
docs (task.add_done_callback(set.discard)).
Refs: Forensics report finding F05
Refactored the BinaryCommandHandler to align with the other command handlers, inheriting from CommandHandlerBase. This resolves an AttributeError and simplifies the command structure. Moved binary_commands.py into the commands module. Applied fixes to the BLE connection handler based on feedback, improving reliability on macOS and ensuring the device address is correctly handled.
