RFR: 8185746: Remove Mutex destructor assertion

[David Holmes]

On 3/08/2017 9:36 AM, Kim Barrett wrote:
>> On Aug 2, 2017, at 7:31 PM, Kim Barrett <kim.barrett at oracle.com> wrote:
>>
>>> On Aug 2, 2017, at 7:23 PM, David Holmes <david.holmes at oracle.com> wrote:
>>>
>>> Hi Kim,
>>>
>>> On 3/08/2017 8:41 AM, Kim Barrett wrote:
>>>> Please review this small change to improve the debugging experience
>>>> when a mutex is destroyed in a bad state.
>>>> I've removed the assert in ~Mutex, which was making the same checks as
>>>> in ~Monitor, but providing much less information.
>>>
>>> Okay. Please can you add a comment to the ~Mutex noting that eg:
>>>
>>> // Defer any state checking to ~Monitor
>>> Mutex::~Mutex() { }
>>
>> Well, I was waffling over just removing it completely.

That works too.

> Note also that the structure here makes it pretty easy to accidentally
> invoke undefined behavior by destructor slicing. That's an entirely
> different problem, but it bugs me...

Please explain.

Thanks,
David