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Re: I use MySQL connectorl and after some time it stops. PLEASE HELP
Posted by: Daniel Wee
Date: February 04, 2017 04:48AM

Hi Chuck - I think I traced the problem and this might be useful for other users.

Basically, the problem comes down to two different issues:-

1. The use of delay(1000) in the connect function, and delay(100) in the wait_for_client function. While this works most of the time, there seems to be some incompatibilities with other interrupt functions with the ESP8266 system under Arduino.

I changed the delay(1000) to use:-

unsigned long sttime=millis();
while (millis()-sttime < 1000) yield();

*likewise for everywhere else delay() appears - especially in MySQL_Packet.cpp

and some other judicious placements of yield() - this completely resolved the apparently random resets and exceptions. After months of experimenting, this actually completely got rid of the problems.

2. There was still the occasional watchdog timeout which I tracked down to the wait_for_client function. This function is called by read_packet and is expected to return an integer.

The way the code is written, however, allows wait_for_client to timeout but without any indication to the read_packet that this has happened. As a result, you could potentially have a situation where the read_packet loops indefinitely while waiting for data that is not forthcoming and thus resulting in a watchdog timeout.

To fix this, I altered wait_for_packet to return a -1 in the event of a timeout, and to check for this result in read_packet so that it can abort in the event of a timeout. Basically, this looks like:-

int avail_bytes = wait_for_client();
if (avail_bytes < 0) return;

* this works after modifying wait_for_client to return a -1 if it timed out.

These two changes fixed all the problems I had been having with mysterious resets. There may be a need to check for timeouts with wait_for_data as well but I have not done that as yet. If I continue to experience problems I may do that.

Could you look at these changes to see if you could incorporate it into the official code. This way I won't have to make the changes manually when new code is released.

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Re: I use MySQL connectorl and after some time it stops. PLEASE HELP
February 04, 2017 04:48AM

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