On Monday, 28 July 2014 at 21:33:54 UTC, Rene Zwanenburg wrote:
If I understand you correctly, an easy way is to use RefCounted
with a simple wrapper. Something like this:
// Descriptor defined by the external library
struct DescriptorImpl
{
size_t type;
void* data;
}
// Tiny wrapper telling the alien GC of the existence of this
reference
private struct DescriptorWrapper
{
DescriptorImpl descriptor;
alias descriptor this;
@disable this();
this(DescriptorImpl desc)
{
// Make alien GC aware of this reference
}
~this()
{
// Make alien GC aware this reference is no longer valid
}
}
// This is the type you will be working with on the D side
alias Descriptor = RefCounted!DescriptorWrapper;
Just read RefCounted definition here,
http://dlang.org/phobos/std_typecons.html#.RefCounted
and it heap allocates its object, so your response above does not
stack allocate the basic type that you call DescriptorWrapper,
and is not a solution to the problem as stated.
If there was no alien GC, but everything else was the same, heap
allocation of something containing a DescriptorImpl would be
unnecessary. Now achieve the same with the alien GC present
without an extra layer of indirection and heap allocation ---
this is the essence of my question.
