Re: FATAL: could not reattach to shared memory (Win32)

Added to TODO:

* Remove use of MAKE_PTR and MAKE_OFFSET macros

  http://archives.postgresql.org/pgsql-general/2007-08/msg01510.php


---------------------------------------------------------------------------

Tom Lane wrote:
> Gregory Stark  writes:
> > "Trevor Talbot"  writes:
> >> I gather postgres depends on it being at the same address, and fixing that
> >> isn't trivial?
> 
> > I haven't been following the rest of the thread so I'm not sure if this is
> > important. But no, fixing that should be relatively trivial as there are
> > already some configurations where it's not the case (the EXEC_BACKEND case I
> > believe). The rest of the system uses a shared memory base pointer and
> > references everything relative to that.
> 
> That hasn't been the case for quite a few years, and we're not going back.
> The pointer-to-offset-and-back gymnastics that that required were
> utterly destructive to code readability and maintainability, mainly
> because if everything stored in shmem data structures is an "offset"
> then you can't get any useful error checking from the compiler about how
> you are using the fields.  It's like decreeing that every pointer
> must be declared "void *" and cast to something else when it's used.
> 
> There are a few old bits of code that still use MAKE_PTR/MAKE_OFFSET,
> but I think it's mostly just that no one's bothered to rewrite the code
> for SHM_QUEUE linked lists.  The vast majority of our shmem structures
> use regular pointers, and have for years.
> 
> 			regards, tom lane
> 
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  Bruce Momjian          http://momjian.us
  EnterpriseDB                             http://postgres.enterprisedb.com

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