Re: IDL issue - struct return vs. cap return

[Neal H. Walfield]

At Tue, 10 Jul 2007 12:05:12 -0400,
Jonathan S. Shapiro wrote:
> Neal: if you have a proposal here, let me know. My main concern is that
> if we cannot efficiently deallocate capability locations, we're going to
> end up taking a lot of page faults.

I suspect that managing capabilities is similar to managing memory and
file descriptors.  In particular, you made the observation that
capability locations are likely to be widely referenced:

At Tue, 10 Jul 2007 10:28:30 -0400, Jonathan S. Shapiro wrote:
> Hmm. Yes. I had not considered the possibility that the receiver might
> have to free capability slots explicitly. This seems very difficult to
> do correctly without GC, since the locations are likely to become widely
> referenced. From a management perspective, in the absence of GC, it
> seems to me that the stub is sitting in the wrong place to make good
> decisions about allocation strategy.

I suspect that this is not the case.  At least, I don't think they
will be more widely referenced than memory or file descriptors.  Thus,
for consistency, I think that whatever approach is taken for managing
these resources (whether that be GC or explicit allocation and
deallocation), should also be used for managing capabilities.

Neal