pthread_cancel and C++11 redux

[Florian Weimer]

* Jonathan Wakely:

> On 26 October 2017 at 15:08, Vuille, Martin (Martin) wrote:
>> Back in 2015, the statement was made:
>> "accept that you shouldn't use pthread_cancel in C++11"
>>
>> (cf. https://gcc.gnu.org/ml/gcc-help/2015-08/msg00040.html)
>>
>> Wondering whether anything has changed or is likely to change?
>> MV
>
> Nothing has changed.

Would it help if you could mark threads as not subject to cancellation
(such as those spawned by a C++ concurrency library)?  Then the caller
of pthread_cancel would get a clean error, and pthread_exit would
abort the process with an explicit error message.