There's still the question of how we have people who write garbage allocators recognise that this is a bug.
Bill. 2009/12/10 Cactus <rieman...@googlemail.com>: > > > On Dec 10, 10:20 pm, Bill Hart <goodwillh...@googlemail.com> wrote: >> Hi Dan, >> >> indeed I had inferred that you had done a *lot* of work to track this bug >> down. >> >> It's not immediately clear how we can cause an error message to be >> output if a custom allocator returns non-aligned pointers. >> >> Two possibilities spring to mind: >> >> 1) Introduce a make check test which checks that the allocator is >> doing what we want. But this relies on the allocator failing to do so >> during the test, which I don't see how to provoke. >> >> 2) Introduce code to align data coming from custom allocators. This >> could probably be done in a handful of cycles per allocation, but >> would still introduce an overhead. >> >> I'm open to further suggestions. > > If n-byte alignment for n-byte objects is a target architecture > requirement, this is surely a memory allocation bug and not an MPIR > one. > > We might think about some sort of debug mode that adds detection or > defence but I would be against adding overhead that is not going to be > necessary in normal operation (we should, of course, document the > issue). > > I would take the view that asking a lot of low level code to defend > against incorrect memory allocation - at possibly heavy cost - is not > the right approach. Whoever has the job of putting a memory allocator > on a machine surely has the responsibility for ensuring that it > complies with any target architecture requirments? > > In particular, I would expect to see a debug mode in an allocator for > testing exactly this sort of issue (I thought that Boehm's GC haad > this capability). > > Brian > > -- > > You received this message because you are subscribed to the Google Groups > "mpir-devel" group. > To post to this group, send email to mpir-de...@googlegroups.com. > To unsubscribe from this group, send email to > mpir-devel+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/mpir-devel?hl=en. > > > -- You received this message because you are subscribed to the Google Groups "mpir-devel" group. To post to this group, send email to mpir-de...@googlegroups.com. To unsubscribe from this group, send email to mpir-devel+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/mpir-devel?hl=en.
