Bruno Haible <[EMAIL PROTECTED]> writes:
> 1) The practical reason is that while developing libsigsegv, I noticed that
> C does not have the notion of a "barrier": In code like this:
>
> set_up_datastructures();
> /* HERE I would like a barrier */
> signal(sig,my_signal_handler);
>
> I would like a barrier to ensure that all memory stores of
> set_up_datastructures() have been performed before the signal handler
> is activated. __asm__("" : : : "memory"); is not portable (works only with
> GCC). Calls to an empty global function are optimized away by GCC 4. [...]
Is it safe to use an external function that is only defined in a
separate translation unit? For example, to define an empty
function in a source file all by itself, then use a call to it as
a barrier. This introduces a barrier in the common situations
that I know about, although there is the small overhead of a
call-and-return sequence. (Are there compilers or linkers that
do inter-module optimization?)
--
"Term, holidays, term, holidays, till we leave school,
and then work, work, work till we die."
C. S. Lewis
