Function hid_read_timeout

lib/hidapi/mac/hid.c:1241–1318

}

int HID_API_EXPORT hid_read_timeout(hid_device *dev, unsigned char *data, size_t length, int milliseconds)
{
	int bytes_read = -1;

	/* Lock the access to the report list. */
	pthread_mutex_lock(&dev->mutex);

	/* There's an input report queued up. Return it. */
	if (dev->input_reports) {
		/* Return the first one */
		bytes_read = return_data(dev, data, length);
		goto ret;
	}

	/* Return if the device has been disconnected. */
	if (dev->disconnected) {
		bytes_read = -1;
		register_device_error(dev, "hid_read_timeout: device disconnected");
		goto ret;
	}

	if (dev->shutdown_thread) {
		/* This means the device has been closed (or there
		   has been an error. An error code of -1 should
		   be returned. */
		bytes_read = -1;
		register_device_error(dev, "hid_read_timeout: thread shutdown");
		goto ret;
	}

	/* There is no data. Go to sleep and wait for data. */

	if (milliseconds == -1) {
		/* Blocking */
		int res;
		res = cond_wait(dev, &dev->condition, &dev->mutex);
		if (res == 0)
			bytes_read = return_data(dev, data, length);
		else {
			/* There was an error, or a device disconnection. */
			register_device_error(dev, "hid_read_timeout: error waiting for more data");
			bytes_read = -1;
		}
	}
	else if (milliseconds > 0) {
		/* Non-blocking, but called with timeout. */
		int res;
		struct timespec ts;
		struct timeval tv;
		gettimeofday(&tv, NULL);
		TIMEVAL_TO_TIMESPEC(&tv, &ts);
		ts.tv_sec += milliseconds / 1000;
		ts.tv_nsec += (milliseconds % 1000) * 1000000;
		if (ts.tv_nsec >= 1000000000L) {
			ts.tv_sec++;
			ts.tv_nsec -= 1000000000L;
		}