poll method
Polls a GPIO for the edge event configured with GPIO.setGPIOedge. For character device GPIOs, the edge event should be consumed with gpio_read_event(). For sysfs GPIOs, the edge event should be consumed with GPIO.read.
Implementation
GPIOpolling poll(int timeoutMillis) {
_checkStatus();
return _checkError(_nativeGPIOpoll(_gpioHandle, timeoutMillis)) == 1
? GPIOpolling.success
: GPIOpolling.timeout;
}