CTFE Status 2

[Steven Schveighoffer via Digitalmars-d]

On 6/6/17 12:39 PM, H. S. Teoh via Digitalmars-d wrote:
> On Tue, Jun 06, 2017 at 02:03:46AM +0000, jmh530 via Digitalmars-d wrote:
>> On Tuesday, 6 June 2017 at 00:46:00 UTC, Stefan Koch wrote:
>>>
>>> Time to find this: roughly 2 weeks.
>>>
>>
>> Damn. That's some commitment.
>
> 2 weeks is not bad for subtle bugs in complex code like this one. In my
> day job I've seen bugs that took 2 *months* to figure out. One of them
> involved a rare race condition that can only be reproduced under very
> specific circumstances, and it took a long time and a lot of guesswork
> before a coworker and myself discovered the exact combination that
> triggered the bug, thereby leading to the subtle problem in a piece of
> code that looked perfectly innocuous before then.

Oh, I've had those before. I had a race condition that reproduced 
*randomly* and usually took about 2 weeks to happen, and that's by 
pounding it non-stop. The result was deadlock. Any debugging after the 
fact resulted in no clues.

Only way I solved it was to print out state as it was going, so I could 
see what happened when the state went bad. I think it took at least 2 
cycles to find it.

This kind of stuff makes you appreciate how important avoiding race 
conditions and memory corruption is.

-Steve