Re: Remove pthread_is_threaded_np() checks in postmaster - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Remove pthread_is_threaded_np() checks in postmaster
Date
Msg-id 20240123222347.4ejkxhbokudcime2@awork3.anarazel.de
Whole thread Raw
In response to Re: Remove pthread_is_threaded_np() checks in postmaster  ("Tristan Partin" <tristan@neon.tech>)
Responses Re: Remove pthread_is_threaded_np() checks in postmaster
List pgsql-hackers
Hi,

On 2024-01-23 15:50:11 -0600, Tristan Partin wrote:
> What is keeping us from using pthread_sigmask(3) instead of sigprocmask(2)?

We would need to make sure to compile with threading support everywhere. One
issue is that on some platforms things get slower once you actually start
using pthreads.


> If an extension can guarantee that threads that get launched by it don't
> interact with anything Postgres-related, would that be enough to protect
> from any fork(2) related issues?

A fork() while threads are running is undefined behavior IIRC, and undefined
behavior isn't limited to a single thread. You'd definitely need to use
pthread_sigprocmask etc to address that aspect alone.

Greetings,

Andres Freund



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