On Tuesday, 16 June 2015 at 14:00:55 UTC, Etienne wrote:
There is a bug regarding unordered object collection in the GC.
My finalizer accesses another GC-allocated object and the
application *sometimes* crashes here:
void _d_invariant(Object o)
{ ClassInfo c;
//printf("__d_invariant(%p)\n", o);
// BUG: needs to be filename/line of caller, not library
routine
assert(o !is null); // just do null check, not invariant
check
c = typeid(o);
^--------- this is the crash location
The culprit seems to be these operations:
00007ff6`881f324b 488b4510 mov rax,qword ptr
[rbp+10h]
00007ff6`881f324f 488b10 mov rdx,qword ptr [rax]
00007ff6`881f3252 488b1a mov rbx,qword ptr [rdx]
ds:00000000`00000000=????????????????
The vtable lookup wants to dereference a null entry. Not sure
how I can fix this, but in the meantime I think typeid could
actually add a small check on RDX and return null if that's
what it is. Any input?
This is undefined behavior, the only solution is "don't do it"
see my thread
http://forum.dlang.org/post/vcpcjujvkbuoswyzy...@forum.dlang.org
destructors as they are shouldn't exist at all, they are
incredibly bug prone.
Bye.
