Re: [gpsd-dev] Does shared memory segment ever get destroyed ?

[Yufeng Shen]

Hi Gary,

So I was talking about the case of shared memory export case (like the
socket export, dbus export)
where client reads the gps_data_t data from the shared memory and gpsd
writes to it.
Not the ntpd case.

Am I making sense or missing something ?

--- Yufeng Shen

On Fri, Nov 4, 2011 at 6:51 PM, Gary E. Miller <address@hidden> wrote:
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> Yo YuFen!
>
> On Fri, 4 Nov 2011, Yufeng Shen wrote:
>
>> Looks like shm_release() only detach from the shared memory segment.
>
> Correct, that is the ntpd protocol.  gpsd did not write that, we just
> do what ntpd wants us to do.
>
>> Otherwise when the gpsd is killed, the client can still attach to the
>> leftover shared memory segment and read old data from it.
>
> Nope, the ntpd protocol has a nice handshake to prevent that.
>
> RGDS
> GARY
> - ---------------------------------------------------------------------------
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
>       address@hidden  Tel:+1(541)382-8588
>
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