Fine-grained locking for POSIX local sockets (UNIX domain sockets)

[Robert Watson]

On Fri, 12 May 2006, Paul Allen wrote:

>> From Andrew Gallatin <gallatin at cs.duke.edu>, Fri, May 12, 2006 at 
>> 04:41:11PM -0400: In addition to this linux vsyscall, there is the 
>> MacOSX/Darwin commpage.  The map machine-specific implementations of atomic 
>> operations, bcopy, bzero, spinlocks, pthread_getspecific, etc into a common 
>> page mapped into userspace applications. The also do a (mostly) 
>> syscall-free gettimeoday this way.
>>
>> See http://fxr.watson.org/fxr/source/osfmk/ppc/commpage/?v=xnu-792
>>
>> Obviously, we could not take the code due to APSL infection (unless Apple 
>> were to donate it), but it is something else to look at.
>
> I've often wondered why they release their code under such a verbose 
> license.  What do they substantively gain relative to the BSD license? Given 
> Jordan Hubbard's position there why does the interaction between FreeBSD and 
> Apple seem to be such an arms length affair?

In the past, we've successfully asked Apple to relicense several pieces of 
code successfully.  One such example is our new Audit implementation in 7.x, 
which was originally under APSL but was re-released under a BSD license for 
inclusion in FreeBSD.  I suggest contacting Kevin Van Vechten <kvv at apple.com>, 
who is responsible for Apple's open source bundling work.  He can't simply 
relicense it, but he may be able to help you figure out the best approach.

Robert N M Watson