A bug in my code

[bearophile]

Sergey Gromov, thank you for your explanations, you are quite clear, I have understood everything you have explained :-) And your code works.

I think this discussion may deserve to become a little tutorial useful for people that have never done such things (probably most people coming from all scripting languages, Pascal, Java and maybe C/C# don't know such things if the haven't seen in the University, so they are lot of people), it may be written here:
http://www.prowiki.org/wiki4d/wiki.cgi?DocComments/Phobos/StdGc


> addRange(&new_block.next, &new_block.data+1);

The trick of adding a range of pointers to pointers is cute :-)
I presume that +1 is necessary because it's an interval open on the right, even if the Phobos docs don't tell it:
void addRange(void* pbot, void* ptop);


>Both require Block.~this() to remove any unneeded roots or ranges<

Okay, I understand now. Jarrett Billingsley has told me that those ranges are inefficient, so I hope the roots are more efficient.

Using your second solution:
addRange(&new_block.next, &new_block.data+1);

I have added this destructor:

~this() {
    while (this.list_head != null) {
        Block* next_ptr = this.list_head.next;
        std.gc.removeRange(&this.list_head.next);
        std.gc.realloc(this.list_head.data, 0);
        std.gc.realloc(this.list_head, 0);
        this.list_head = next_ptr;
    }
}


Now I think I understand the Phobos GC API a bit better. But I'll have to be really careful, because doing mistakes with such things looks very easy still for me.

Bye and thank you,
bearophile