On Wed, Jan 30, 2019 at 9:15 PM 'Kenton Varda' via v8-users < v8-users@googlegroups.com> wrote:
> One more low-level question (where it seems like implementation details > matter to embedders): > > Based on what you've said, an object may or may not be "black" on > allocation. It seems, though, that I need to do different things depending > on the color. If it is allocated black, then I need to arrange to trace the > object myself to register all its outgoing references. If it is white, then > I need to call RegisterExternalReference(), and V8 will trace it later. If > it's gray, I don't need to do anything. > > But if I don't know the color, it seems I need to *both* call > RegisterExternalReference() and initiate my own trace to cover all bases. > But in the case that it's not already-black, this will result in a > redundant trace later on. > > The redundant trace can be avoided by having a color marker on the C++ object itself so that it only traces through it once. Ultimately, solving all those issues leads to having a fully trace-based system with marking colors on the C++ side too. We went that way because we need a system to collect reference cycles and the easiest way to do so is by basing the whole system on tracing. > Is it best to live with this potential redundant trace, or is there some > way I can detect the color after allocation? > There's no way to detect the color as we have changed the internal implementation in the past and may do so in future. -Michael -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
