Important changes to forums and questions
All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.
6 years, 9 months ago.
Client cycle
Hello, when calling Yeld, with socket timed out, the cycle function detects negative values from socket recv as an error and 0 as socket timeout (see code fragment below):
int packet_type = readPacket(timer); read the socket, see what work is due
switch (packet_type) { default: no more data to read, unrecoverable. Or read packet fails due to unexpected network error rc = packet_type; goto exit; case 0: timed out reading packet break;
While the Mbed recv specs says: "By default, recv blocks until data is sent. If socket is set to non-blocking or times out, NSAPI_ERROR_WOULD_BLOCK is returned immediately."
So, in the case of socket time out, the returned value, if the brocker has nothing to send, will be NSAPI_ERROR_WOULD_BLOCK wich is not an error but just an indication of no incoming data. Unfortunatly the readPacket interpret it as an error causing the MQTT client to close the connection. Is this the correct behaviour? Thank you, best regards
Question relating to:
![](/media/cache/profiles/mqtt.png.50x50_q85.png)
Assigned to
6 years, 9 months ago.This means that the question has been accepted and is being worked on.
The MQTT library has been updated in the last week with changes that should address this situation.
posted by Ian Craggs 07 Nov 2017Hello, thank you for commenting, i already checked the latest Rev 59 https://os.mbed.com/teams/mqtt/code/MQTT/rev/9cff7b6bbd01 it seems it has the same issue.
posted by Licio Mapelli 08 Nov 2017This is the proposed patch on file MQTTClient.h: @@ -590,7 +590,8 @@ no more data to read, unrecoverable. Or read packet fails due to unexpected network error rc = packet_type; goto exit; - case 0: timed out reading packet + case NSAPI_ERROR_WOULD_BLOCK: + case NSAPI_ERROR_OK: timed out reading packet
posted by Licio Mapelli 08 Nov 2017All OS specific code goes into the modules below MQTTClient.h. The changes dealing with these error codes are in MQTTSocket.h.
posted by Ian Craggs 24 Nov 2017MQTTSocket(EthernetInterface *anet) how to pass NetworkInterface * from easy-connect?
posted by Licio Mapelli 27 Nov 2017