Return flag from poll() to allow conditional events to trigger

[nsted]

Returning a flag from server's poll() is helpful to allow code conditionally execute when a new packet is received. For example, we may want to update holding registers after the last values were collected by the client. Using the flag is optional and can be ignored, using poll() as it has been.

[CLAassistant]

All committers have signed the CLA.

[github-actions]

Memory usage change @ 068f31b

Board	flash	%	RAM for global variables	%
arduino:avr:leonardo	🔺 +20 - +24	+0.07 - +0.08	0 - 0	0.0 - 0.0
arduino:avr:nano	🔺 +20 - +24	+0.07 - +0.08	0 - 0	0.0 - 0.0
arduino:mbed:envie_m7	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:mbed:nano33ble	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0
arduino:megaavr:uno2018:mode=off	🔺 +20 - +26	+0.04 - +0.05	0 - 0	0.0 - 0.0
arduino:samd:mkrwifi1010	🔺 +8 - +24	0.0 - +0.01	0 - 0	0.0 - 0.0

Click for full report table

Board	examples/RTU/ModbusRTUClientKitchenSink flash	%	examples/RTU/ModbusRTUClientKitchenSink RAM for global variables	%	examples/RTU/ModbusRTUClientToggle flash	%	examples/RTU/ModbusRTUClientToggle RAM for global variables	%	examples/RTU/ModbusRTUServerKitchenSink flash	%	examples/RTU/ModbusRTUServerKitchenSink RAM for global variables	%	examples/RTU/ModbusRTUServerLED flash	%	examples/RTU/ModbusRTUServerLED RAM for global variables	%	examples/RTU/ModbusRTUTemperatureSensor flash	%	examples/RTU/ModbusRTUTemperatureSensor RAM for global variables	%	examples/TCP/EthernetModbusClientToggle flash	%	examples/TCP/EthernetModbusClientToggle RAM for global variables	%	examples/TCP/EthernetModbusServerLED flash	%	examples/TCP/EthernetModbusServerLED RAM for global variables	%	examples/TCP/WiFiModbusClientToggle flash	%	examples/TCP/WiFiModbusClientToggle RAM for global variables	%	examples/TCP/WiFiModbusServerLED flash	%	examples/TCP/WiFiModbusServerLED RAM for global variables	%
arduino:avr:leonardo	20	0.07	0	0.0	20	0.07	0	0.0	20	0.07	0	0.0	24	0.08	0	0.0	20	0.07	0	0.0	20	0.07	0	0.0	20	0.07	0	0.0
arduino:avr:nano	20	0.07	0	0.0	20	0.07	0	0.0	20	0.07	0	0.0	24	0.08	0	0.0	20	0.07	0	0.0	20	0.07	0	0.0	20	0.07	0	0.0
arduino:mbed:envie_m7	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0
arduino:mbed:nano33ble	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0
arduino:megaavr:uno2018:mode=off	22	0.05	0	0.0	22	0.05	0	0.0	22	0.05	0	0.0	26	0.05	0	0.0	22	0.05	0	0.0	22	0.05	0	0.0	20	0.04	0	0.0	22	0.05	0	0.0	20	0.04	0	0.0
arduino:samd:mkrwifi1010	8	0.0	0	0.0	8	0.0	0	0.0	8	0.0	0	0.0	16	0.01	0	0.0	8	0.0	0	0.0	8	0.0	0	0.0	24	0.01	0	0.0	8	0.0	0	0.0	24	0.01	0	0.0

Click for full report CSV

Board,examples/RTU/ModbusRTUClientKitchenSink<br>flash,%,examples/RTU/ModbusRTUClientKitchenSink<br>RAM for global variables,%,examples/RTU/ModbusRTUClientToggle<br>flash,%,examples/RTU/ModbusRTUClientToggle<br>RAM for global variables,%,examples/RTU/ModbusRTUServerKitchenSink<br>flash,%,examples/RTU/ModbusRTUServerKitchenSink<br>RAM for global variables,%,examples/RTU/ModbusRTUServerLED<br>flash,%,examples/RTU/ModbusRTUServerLED<br>RAM for global variables,%,examples/RTU/ModbusRTUTemperatureSensor<br>flash,%,examples/RTU/ModbusRTUTemperatureSensor<br>RAM for global variables,%,examples/TCP/EthernetModbusClientToggle<br>flash,%,examples/TCP/EthernetModbusClientToggle<br>RAM for global variables,%,examples/TCP/EthernetModbusServerLED<br>flash,%,examples/TCP/EthernetModbusServerLED<br>RAM for global variables,%,examples/TCP/WiFiModbusClientToggle<br>flash,%,examples/TCP/WiFiModbusClientToggle<br>RAM for global variables,%,examples/TCP/WiFiModbusServerLED<br>flash,%,examples/TCP/WiFiModbusServerLED<br>RAM for global variables,%
arduino:avr:leonardo,20,0.07,0,0.0,20,0.07,0,0.0,20,0.07,0,0.0,24,0.08,0,0.0,20,0.07,0,0.0,20,0.07,0,0.0,20,0.07,0,0.0
arduino:avr:nano,20,0.07,0,0.0,20,0.07,0,0.0,20,0.07,0,0.0,24,0.08,0,0.0,20,0.07,0,0.0,20,0.07,0,0.0,20,0.07,0,0.0
arduino:mbed:envie_m7,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,,,,,,,,
arduino:mbed:nano33ble,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,,,,,,,,
arduino:megaavr:uno2018:mode=off,22,0.05,0,0.0,22,0.05,0,0.0,22,0.05,0,0.0,26,0.05,0,0.0,22,0.05,0,0.0,22,0.05,0,0.0,20,0.04,0,0.0,22,0.05,0,0.0,20,0.04,0,0.0
arduino:samd:mkrwifi1010,8,0.0,0,0.0,8,0.0,0,0.0,8,0.0,0,0.0,16,0.01,0,0.0,8,0.0,0,0.0,8,0.0,0,0.0,24,0.01,0,0.0,8,0.0,0,0.0,24,0.01,0,0.0

[aentinger]

LGTM 👍 (after resolving the merge conflict).