Re: Postgres-R: internal messaging

Alexey Klyukin <alexk@commandprompt.com> writes:
> Markus Wanner wrote:
>> I'm currently doing this with imessages as well,  
>> which violates the rule that the postmaster may not to touch shared  
>> memory. I didn't look into ripping that out, yet. I'm not sure it can be  
>> done with the existing signaling of the postmaster.

> In Replicator we avoided the need for postmaster to read/write backend's
> shmem data by using it as a signal forwarder.

You should also look at the current code for communication between
autovac launcher and autovac workers.  That seems to be largely a
similar problem, and it's been solved in a way that seems to be
safe enough with respect to the postmaster vs shared memory issue.
        regards, tom lane