On 2012-04-20 20:45:11 +0000, Manu <[email protected]> said:
I need to clarify some things that have confused me a few times. I've
reconsidered these basic attributes a few times, and I thought I understood
them, but I obviously don't.
The case that has confused me is here:
http://d.puremagic.com/issues/show_bug.cgi?id=7897
In the global scope:
int x; <- x is TLS
but:
static int x; <- this is... a 'static' global instance, whatever that
means? Is this TLS or not?
If you're trying to make a C-like global, write this:
static __gshared int x;
"static" here is optional if you are at global scope. "__gshared" is a
storage class which basically mean "no TLS": the global variable is
available to all threads (C-style).
Note that because "__gshared" is a storage class (and not a type
constructor), the type of x is "int", not "shared(int)". So, despite
the same address being seen by all threads, it'll be treated as if it
was a thread-local variable as far as the type system is concerned.
One could say that shared and immutable global variables are implicitly
"__ghsared", in the sense that they are not in TLS, because they have a
type qualifier that make it safe to be visible in all threads.
--
Michel Fortin
[email protected]
http://michelf.com/
