Re: posix 4 extensions

Johnie Stafford (
Wed, 31 Jul 96 07:26 CDT

>>> On Wed, 31 Jul 1996 09:12:35 +0200, Volker Eberlein Guest at ROBERT BOSCH GmbH FV/SLH <> said:

ve> Johnie Stafford wrote:
>> What about the posix.4 shared memory objects? Any chance we might ever
>> see them? The ability to map shared memory segments to the same
>> logical address in several different processes would make the use of
>> pointers in shared memory possible.
>> Johnie

ve> Though I am pretty anxiously waiting for the posix.1b/posix.4
ve> features as well, I would like you to take notice of the fact
ve> that the feature of attaching a shared mem segment to a specified
ve> address is already given with SysV IPC.

ve> shm_root_p = shmat (shm_id, (char *)0xa0000000 ,0);

ve> is a possible action. But anyway: the 'clean' solution for pointers
ve> in shared memory would always be having addresses relative to the
ve> segment's borders.

That is more-or-less what we do, but I really hate specifying an
absolute address in a program.


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