Amazing Difference A Character Can Make
Today I had an amazing debugging session with some code I'd written and thought was in pretty good shape. It took most of the day, but there were really several things I needed to figure out in the test case I was given. Basically, it was an extreme edge case, and yet, it was possible, so it needed to be handled properly.
But the final bug was a doozie. The original code looked like this:
const uint128_t & ckey = aMessage->getConflationKey();
and in that simple line there was the final bug.
If we had multiple threads hitting the same code, it was possible to have these messages cleaned out. But what happens when you delete the aMessage and you have a reference to a value in it? Well... it goes to poo, that's what. The fix was simple:
uint128_t ckey = aMessage->getConflationKey();
One character - the ampersand. That's it. Make a copy as opposed to holding onto a reference. One character. Amazing.
Some days I love this job.