Re: Question: Why Are File Descriptors Not Closed and Accounted for PostgreSQL Backends?

[Heikki Linnakangas]

On 24/05/2024 15:17, Srinath Reddy Sadipiralla wrote:
Hi PostgreSQL Community,
when a backend process starts, pq_init is called where it opens a FD during 
CreateWaitEventSet()

if (!AcquireExternalFD())
{
/* treat this as though epoll_create1 itself returned EMFILE */
elog(ERROR, "epoll_create1 failed: %m");
}
set->epoll_fd = epoll_create1(EPOLL_CLOEXEC);


but we didn't closed or called ReleaseExternalFD() for accounting

Yes we do, see FreeWaitEventSet().

The WaitEventSet created fro pq_init() is never explicitly free'd 
though, because it's created in the per-connection backend process. When 
the connection is terminated, the backend process exits, cleaning up any 
resources including the WaitEventSet.

--
Heikki Linnakangas
Neon (https://neon.tech)