Undefined behaviour in Cola2Session and Command?

[mlederhi]

From looking at the code I saw the following two things:

Could it be that the mutex of a command is locked in thread A when Cola2Session::sendTelegramAndListenForAnswer is called, and then unlocked in thread B (ASIO io service thread) when Cola2Session::processPacket is called when the answer is received? If this is the case, then this is undefined behavior.

Also what happens, when a command is sent, and no answer is received (because of some error). Is the mutex then never unlocked?

[puck-fzi]

Hi, thanks for spotting this. I think you are correct with the undefined behavior. It should not occur that the unlock will be triggered before the lock; however, you are correct that it's undefined behavior in the current version.

And for the second part, yes, it would lock permanently currently, so maybe a timeout would be beneficial.

[mlederhi]

Maybe you can use something like pull request #145 to address the first problem.