debug container mutex association

[Jonathan Wakely]

On 19/09/16 21:56 +0200, François Dumont wrote:
>Hi
>
>    Following our conversation here is a much simpler patch. I just 
>consider that all debug containers will have the same alignment.
>
>    Even if I submit this patch as a whole I will commit into pieces, 
>at least one for the pure cleanup parts and one for the debug.cc 
>change.
>
>    Among those changes there is:
>-       __gnu_cxx::__scoped_lock(this->_M_get_mutex());
>+       __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
>
>    I would appreciate if you could tell me what was happening with 
>the initial expression. I don't understand why it is compiling. I even 
>tried the same in debug.cc and started having compilation errors.

It creates a temporary __scoped_lock, which immediately goes out of
scope and unlocks the mutex again. This should be fixed on the gcc-5
and gcc-6 branches too.

I'll review the rest of the patch today.