[PATCH v3] Test case for BZ 19329

[Szabolcs Nagy]

https://sourceware.org/ml/libc-alpha/2016-12/msg00456.html
ping 2.

i think v3 is safe and does not waste resources.

the only hack is the relaxed atomic operations, but i
wanted to avoid introducing additional barriers and the
correctness of the test does not depend on ordering.
if that's considered bad then those can be changed to
acquire/release atomics.

On 19/12/16 13:24, Szabolcs Nagy wrote:
> ping.
> 
> On 13/12/16 12:28, Szabolcs Nagy wrote:
>> Test concurrent dlopen and pthread_create when the loaded
>> modules have TLS.  This triggers dl-tls assertion failures
>> more reliably than the tst-stack4 test.
>>
>> The dlopened module has 100 DT_NEEDED dependencies, the
>> number of concurrent threads created during dlopen depends
>> on filesystem speed and hardware.
>>
>> Doing the test in a fork loop can make it more reliable.
>>
>> v2:
>> - undef NDEBUG.
>> - join nop threads so at most 3 threads exist at a time.
>> - remove stack size setting (resource usage is no longer a concern).
>> - stop creating threads after dlopen observably finished.
>> - print the number of threads created for debugging.
>>
>> v3:
>> - use the new test support code.
>> - better Makefile usage so modules are cleaned properly.
>>
>> 2016-12-13  Szabolcs Nagy  <szabolcs.nagy@arm.com>
>>
>> 	* nptl/Makefile (tests): Add tst-tls7.
>> 	(modules-names): Add tst-tls7mod, tst-tls7mod-dep.
>> 	* nptl/tst-tls7.c: New file.
>> 	* nptl/tst-tls7mod-dep.c: New file.
>> 	* nptl/tst-tls7mod.c: New file.
>>
>