Check MDIO server thread joinable before join the thread

[jiahua-wang]

This PR is to address the issue syncd crash observed during sonic-mgmt reboot tests #17346

[kcudnik]

Is the root case already known? Was it double join?

[jiahua-wang]

Double join could be an explanation. More likely scenario is that m_taskThread is not joinable because after MdioIpcServer constructor startMdioThread() was not called or because startMdioThread() failed. @kenneth-arista can provide more test details.

[kcudnik]

Double join could be an explanation. More likely scenario is that m_taskThread is not joinable because after MdioIpcServer constructor startMdioThread() was not called or because startMdioThread() failed. @kenneth-arista can provide more test details.

Can you investigate which exactly scenario is that ?

[kenneth-arista]

Double join could be an explanation. More likely scenario is that m_taskThread is not joinable because after MdioIpcServer constructor startMdioThread() was not called or because startMdioThread() failed. @kenneth-arista can provide more test details.

Can you investigate which exactly scenario is that ?

Unfortunately, I don't have all the logs when the problem occurred before integrating Jiahua's patch. Prior to the patch, I would often seen several syncd core files after each full sonic-mgmt test runs. I suspect these crashes are triggered in tests involving reboot.

[kenneth-arista]

I recall that a syncd crash was observed once during sonic-mgmt override_config_table tests.

[jiahua-wang]

This patch will address both cases of double join and thread not starting properly.

[rlhui]

@jiahua-wang - please update the branch? thanks

[xumia]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[jiahua-wang]

/azp run

[azure-pipelines]

Commenter does not have sufficient privileges for PR 1342 in repo sonic-net/sonic-sairedis

[jiahua-wang]

/AzurePipelines run Azure.sonic-sairedis

[azure-pipelines]

Commenter does not have sufficient privileges for PR 1342 in repo sonic-net/sonic-sairedis

[judyjoseph]

@kcudnik Can we merge this PR

[judyjoseph]

/AzurePipelines run Azure.sonic-sairedis

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[jiahua-wang]

@kcudnik @rlhui @judyjoseph All checks were passed when I created the PR for the first time. After I merged other commits, 2 checks always fail at the place not related to my code change. Should I close this one and create another one with the same code change?

[kcudnik]

All passed do you want me to merge?

[jiahua-wang]

@kcudnik Please merge.