reading the byte failed. If there was no byte to read, and only then, errno will contain EWOULDBLOCK or EAGAIN. For all other values of errno this always signals a critical error.
Poll.readControl
bool readControl()Read a byte from the control socket of the controllable set.
This function only works for timer #GstPoll objects created with [gst.poll.Poll.newTimer].
Returns
true on success. false when when there was no byte to read or