[ntp:questions] new driver development

Joseph Gwinn joegwinn at comcast.net
Sun Mar 20 17:14:02 UTC 2011

In article <j_mdnRCPIta18hjQnZ2dnUVZ_tudnZ2d at megapath.net>,
 hal-usenet at ip-64-139-1-69.sjc.megapath.net (Hal Murray) wrote:

> In article <2wlgp.34776$d46.31874 at newsfe07.iad>,
>  Bruce Lilly <bruce.lilly at gmail.com> writes:
> > o POSIX mutex for synchronized access to shared memory for updates
> >   -- obviates mode 0 / mode 1 / OLDWAY
> I'm far from a POSIX wizard.  When I google for >POSIX mutex< I get
> a bunch of hits that all are part of pthreads.

Pthreads moved into POSIX, so no surprise.

> Does that stuff work across processes rather than threads?
> The mutex needs to be in shared memory so both processes can get at it.
> Right?  Who initializes it?

It would be best to read the actual standard.  Mutexes spanning shared 
memory are supported, for exactly the reasons you list.

POSIX.1: <http://pubs.opengroup.org/onlinepubs/9699919799/>.

And the general history: <http://en.wikipedia.org/wiki/POSIX>

Joe Gwinn

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