[PATCH] pthread_once hangs when init routine throws an exception [BZ #18435]

[Torvald Riegel]

On Mon, 2015-06-01 at 12:41 -0600, Martin Sebor wrote:
> Beyond call_once, C++ 11 encourages implementations to
> provide a member function called native_handle() that
> returns a reference to the underlying native object.
> libstdc++ mutex (and other classes) expose this member
> function to provide interoperability with pthreads. As
> a result, reimplementing libstdc++ independently of libc
> is impossible without losing such interoperability and
> without breaking compatibility with existing code.

Note that the interoperability is also a dependency.  I think it's
actually better for libstdc++ to not make an ABI guarantee that
native_handle() returns a pointer to a PThreads entity;  this way, we do
have the freedom to improve libstdc++ independently of glibc and more
importantly of POSIX.
I don't know for sure whether Jonathan has applied the change already,
but IIRC, we agreed that native_handle() should return void*.