On Friday, 21 September 2012 at 20:43:13 UTC, Jonathan M Davis
wrote:
On Friday, September 21, 2012 15:59:31 Andrei Alexandrescu
wrote:
On 9/19/12 4:11 PM, "Øivind" wrote:
> New question for you :)
>
> To register benchmarks, the 'scheduleForBenchmarking' mixin
> inserts a
> shared static initializer into the module. If I have a
> module A and a
> module B, that both depend on eachother, than this will
> probably not
> work..? The runtime will detect the init cycle and fail with
> the
> following error:
>
> "Cycle detected between modules with ctors/dtors"
>
> Or am I wrong now?
I think you have discovered a major issue. Ideas on how to
attack this?
Some of us have been asking for ages for the ability to mark a
static
constructor as not depending on anything so that the runtime
_doesn't_ think
that there's a circular dependency, but Walter has been against
the idea when
it's been brought up. That would _really_ help here.
Without redesigning std.benchmark so that it doesn't use static
constructors,
I don't know how you can fix that. Normally, if you really need
a static
constructor, you go through the pain of creating a separate
module which does
the initialization for you (like std.stdio does). But that
won't work in this
case, because you're mixing it in. So, unless you can redesign
it so that
std.benchmark doesn't require static constructors, it may have
to be a
limitation of std.benchmark that it can't be used where it
would create a
circular dependency.
Unfortunately, the circular dependency issue makes static
constructors almost
useless outside of isolated cases, even though they rarely
actually have
circular dependencies. It's one of the few places in D that I'd
say that
there's a major design flaw.
- Jonathan M Davis
Is there a way to solve the dependency issue without forbidding
static constructors in modules with cyclic dependencies?
I.e. for two modules with static init referencing eachother, an
analysis of the static init code could be used to detect circular
dependencies instead of the import statements?
