[B2-devel] Re: Direct Addressing and Darwin/MacOS X

[<ni...@in...>]

...
> Having said that, I have just realized Darwin doesn't honor the
> protection flags passed to mmap() (say PROT_READ only). So, an explicit
> mprotect() has to be done just after that. I am going to wrap a number
> of mmap()/mprotect() functions to reflect that and also the fact that
> Darwin doesn't support mapping memory from device files (MAP_ANON works
> though).

1) Wrappers? Good idea.

2) Sounds like you have had more success than I.
   I wasn't able to use _any_ mmap() calls under OS X.
   (it always gives an errno that says the function is unimplemented)

3) You may want to investigate the map_fd(), vm_allocate() and
   vm_deallocate() calls in this old Rhapsody (NextStep) document:

   http://developer.apple.com/techpubs/macosx/Legacy/Mach.pdf

   (Take a copy of it. It may disappear)


...
> Note: vm_protect() exists in Mach/Darwin environments but with 4
> arguments. This is not a problem since we use C++. Could this be a
> problem for Objective C if Nigel wants to have the same naming
> conventions ?

	Won't be a problem, as my MacOS X port currently doesn't use
main_unix.cpp anyway. (most of its stuff is in cpp_glue_MacOSX.cpp)

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