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#1 (**permalink**) 04-12-2008, 05:39 AM

Hello, I'm hacking postgresql code to add some custom features but I met the following problem:

I need to call a function right before frontend disconnects, so I looked for the section where frontend closes down the socket in PostgresMain (postgres.c)and I read the comment under "case 'X'" which states not to add code there but to set up a proc_exit callback. Then I looked at proc_exit code and here comes my problem: proc_exit calls shmem_exit BEFORE executing callbacks, but my function needs to access shared memory. My temporarily solution was to modify proc_exit, scanning callbacks to find my function and executing it before shmem_exit (I get a signal 11 otherwise): is it a good solution? Is there a more appropriate section to add a function call right before frontend disconnects than a proc_exit callback? Thank you.

Regards,
Claudio Rossi

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#2 (**permalink**) 04-12-2008, 05:39 AM

"Claudio Rossi" <wind.claudio@inwind.it> writes:
> Is there a more appropriate section to add a function call right before frontend disconnects than a proc_exit callback? Thank you.

on_shmem_exit

regards, tom lane

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Accessing shared memory in a proc_exit callback