Re: Feature: POSIX Shared memory support

Tom Lane wrote:
> Magnus Hagander <magnus(at)hagander(dot)net> writes:
>> Tom Lane wrote:
>>> Magnus Hagander <magnus(at)hagander(dot)net> writes:
>>>> If we just didn't add the serial number at the end, then it would be
>>>> impossible to create a shared memory segment for the same port again.
>>>> That protects the port and not the datadir. But what if we change the
>>>> name of the shared memory segment to be that of the data directory
>>>> instead of the port?
>>> That would help if there's only one possible spelling of the data
>>> directory path ... otherwise not so much ...
>
>> Well, we could run GetFullPathName() on it
>> (http://msdn2.microsoft.com/en-us/library/aa364963.aspx). I think that
>> should work - takes out the "relative vs absolute path" part at least.
>
>> It won't take care of somebody having a junction pointing at the data
>> directory and starting it against that one, but that's really someone
>> *trying* to break the system. You wouldn't do that by mistake...
>
>> Seems worthwhile to you? If so I can take a look at doing it when I get
>> some spare time.
>
> Sounds reasonable --- certainly it'd be better than the current
> situation. I assume that we can have long enough shared memory segment
> names that the data directory path length isn't unduly constrained?

From what I can see, we can have a shared memory segment name that is
just as long as any path name. Will run some tests on that to make
absolutely sure.

//Magnus