On 08/17/2011 10:37 AM, Blue Swirl wrote:
> I would agree (just did it for fun and to see how it looks like), but
> perhaps we can do something similar to what Windows does for OpenBSD too.
>
> Though I'm quite disappointed and I must say OpenBSD should enter the 21st
> century.
I can't justify their design decisions, but isn't __thread a
non-standard extension by GCC anyway whereas POSIX threads are the
standard? Are other compilers supporting it?
Visual C++ supports __declspec(thread).
pthread TLS is orders of magnitudes slower than __thread. __thread in
an executable is just as fast as a non-TLS variable access, 2 or 3
machine language instructions at most.
Some pthread_getspecific implementation do a _linear walk_ of the keys.
In that case it may work to have something like Windows plus a single
pthread_getspecific key. On the other hand, Windows provides very good
support for that thanks to its ordered subsections (.tls$something). It
only needs a bit of preprocessor magic. Thinks such as linker scripts
would be way out of scope.
Paolo
