Re: Memory leak in WAL sender with pgoutput (v10~)

On 2024-Nov-30, Michael Paquier wrote:

> After sleeping on that, and because the leak is minimal, I'm thinking
> about just applying the fix only on HEAD and call it a day. This
> changes the structure of Publication so as we use a char[NAMEDATALEN]
> rather than a char*, avoiding the pstrdup(), for the publication name
> and free it in the list_free_deep() when reloading the list of
> publications.

I'm not sure about your proposed fix. Isn't it simpler to have another
memory context which we can reset instead of doing list_free_deep()? It
doesn't have to be a global memory context -- since this is not
reentrant and not referenced anywhere else, it can be a simple static
variable in that block, as in the attached. I ran the stock tests (no
sysbench) and at least it doesn't crash.

This should be easily backpatchable also, since there's no ABI change.

--
Álvaro Herrera Breisgau, Deutschland — https://www.EnterpriseDB.com/