Make implementation of Arduino WiFi101 (v0.8.0) WiFiClient.write() method non blocking (but data-loss)

gistfile1.cpp

// For file src/WiFiClient.cpp change ths method:

size_t WiFiClient::write(const uint8_t *buf, size_t size)
{
	sint16 err;

	if (_socket < 0 || size == 0) {
		setWriteError();
		return 0;
	}

	// Network led ON (rev A then rev B).
	m2m_periph_gpio_set_val(M2M_PERIPH_GPIO16, 0);
	m2m_periph_gpio_set_val(M2M_PERIPH_GPIO5, 0);

	m2m_wifi_handle_events(NULL);

	while ((err = send(_socket, (void *)buf, size, 0)) < 0) {
		// Exit on fatal error, retry if buffer not ready.
		if (err != SOCK_ERR_BUFFER_FULL) {
			setWriteError();
			m2m_periph_gpio_set_val(M2M_PERIPH_GPIO16, 1);
			m2m_periph_gpio_set_val(M2M_PERIPH_GPIO5, 1);
			return 0;
		}
		m2m_wifi_handle_events(NULL);
	}

	// Network led OFF (rev A then rev B).
	m2m_periph_gpio_set_val(M2M_PERIPH_GPIO16, 1);
	m2m_periph_gpio_set_val(M2M_PERIPH_GPIO5, 1);

	return size;
}

// into:

size_t WiFiClient::write(const uint8_t *buf, size_t size)
{
	sint16 err;

	if (_socket < 0 || size == 0) {
		setWriteError();
		return 0;
	}

	// Network led ON (rev A then rev B).
	m2m_periph_gpio_set_val(M2M_PERIPH_GPIO16, 0);
	m2m_periph_gpio_set_val(M2M_PERIPH_GPIO5, 0);

	m2m_wifi_handle_events(NULL);

	unsigned long t1 = millis();
	unsigned long t2 = t1;
	while ((err = send(_socket, (void *)buf, size, 0)) < 0) {
		t2 = millis();
		if ((t2-t1) > 3) {  // sending has to be completed by 3 ms (can change this), otherwise exit
			return 0;
		}
		// Exit on fatal error, retry if buffer not ready.
		if (err != SOCK_ERR_BUFFER_FULL) {
			setWriteError();
			m2m_periph_gpio_set_val(M2M_PERIPH_GPIO16, 1);
			m2m_periph_gpio_set_val(M2M_PERIPH_GPIO5, 1);
			return 0;
		}
		m2m_wifi_handle_events(NULL);
	}

	// Network led OFF (rev A then rev B).
	m2m_periph_gpio_set_val(M2M_PERIPH_GPIO16, 1);
	m2m_periph_gpio_set_val(M2M_PERIPH_GPIO5, 1);

	return size;
}