openEvents method
Opens a stream of raw edge events for a line-request descriptor.
Behind the seam like every other syscall, so a test can supply events without a kernel, a chip, or a spawned isolate.
Implementation
@override
Future<GpioEventReader> openEvents(int fd) async {
final request = _requestFds[fd];
if (request == null) {
throw StateError('no such request descriptor: $fd');
}
final reader = _FakeEvents(request);
_eventReaders[fd] = reader;
request.chip.onEdge = _emit;
return reader.asReader();
}