On Sunday, 18 December 2011 at 23:55:17 UTC, Timon Gehr wrote:
On 12/19/2011 12:45 AM, Vladimir Panteleev wrote:
On Sunday, 18 December 2011 at 23:31:03 UTC, Timon Gehr wrote:
On 12/19/2011 12:24 AM, Vladimir Panteleev wrote:
On Sunday, 18 December 2011 at 23:18:22 UTC, Timon Gehr
wrote:
You are right. I have had in mind a generational GC that
uses a
copying collector for the nursery as this is what most
state-of-the-art VM GCs do.
These changes are too invasive for the language at this
point, I
believe. We need to work with what we have.
I disagree. Code that relies on other semantics would just
have to use
conservative GC.
Please elaborate on how you would hypothetically change D to
accustom
such changes. I am having trouble imagining such an
implementation that
would not have a considerable impact on D's performance.
If you have an union
union X{
int x;
int* y;
}
The compiler would just lay out x and y sequentially instead of
at the same memory location. Alternatively, it could add a tag
to each union.
In case of passing GC memory to C functions, I would prefer to
just disallow the C code to capture the reference, and to
disable GC while the C function runs. (disabling and enabling
GC is just a matter of modifying a counter somewhere, that
should not visibly impact performance.) If C code was to
capture a reference to the memory then it would probably take
ownership anyway, which would necessitate to allocate the
memory with malloc even with conservative GC.
I am not sure what to do about void[] though.
OK... but what about the "generational GC that uses a copying
collector for the nursery"?
