Shmem queue is not flushed if receiver is not yet attached

From: Pavan Deolasee <pavan(dot)deolasee(at)gmail(dot)com>
To: PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Cc: Robert Haas <robert(dot)haas(at)enterprisedb(dot)com>, Tomas Vondra <tomas(dot)vondra(at)enterprisedb(dot)com>
Subject: Shmem queue is not flushed if receiver is not yet attached
Date: 2022-03-17 07:12:58
Message-ID: CABOikdPkwtLLCTnzzmpSMXo3QZa2yXq0J7Q61ssdLFAJYrOVvQ@mail.gmail.com
Views: Whole Thread | Raw Message | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Hello,

While testing on the current PG master, I noticed a problem between
backends communicating over a shared memory queue. I think `shm_mq_sendv()`
fails to flush the queue, even if `force_flush` is set to true, if the
receiver is not yet attached to the queue. This simple fix solves
the problem for me.

On another note, `shm_mq.h` declares `shm_mq_flush()`, but I don't see it
being implemented. Maybe just a leftover from the previous work? Though it
seems useful to implement that API.

Thanks,
Pavan

--
Pavan Deolasee
EnterpriseDB: https://www.enterprisedb..com

Attachment Content-Type Size
0001-Flush-the-queue-even-if-receiver-has-not-attached.patch application/octet-stream 1.5 KB

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Michael Paquier 2022-03-17 07:22:14 Re: Out-of-tree certificate interferes ssltest
Previous Message osumi.takamichi@fujitsu.com 2022-03-17 07:09:29 RE: Skipping logical replication transactions on subscriber side