Re: [Valgrind-users] helgrind and threadsafe-statics

[Bart V. A. <bva...@ac...>]

On 06/09/14 13:16, Olivier Goffart wrote:
> On Monday 09 June 2014 09:53:37 Bart Van Assche wrote:
>> If g++ would be modified such that the "if (!guard.first_byte)" test can
>> be skipped at run-time then it would become possible for Helgrind and
>> DRD to recognize static initialization by intercepting the
>> __cxa_guard_*() functions. However, I'm not sure which mechanism the gcc
>> maintainers will prefer for disabling that if-test at run-time.
> 
> Just an idea: Is it not possible to record guard's address on 
> __cxa_guard_release, and then consider that an access to guard as an happens 
> after?
> I don't know the internals of helgrind, so I can't say if it is possible, or 
> if it would be too slow.
> Or is __cxa_guard_* used for more than the static initialization?

This is certainly possible but I don't see how to implement this without
slowing down Helgrind and DRD significantly.

Bart.