From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thomas Munro <thomas.munro@gmail.com>
cc: Alexander Lakhin <exclusion@gmail.com>,
        pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: Regression tests fail on OpenBSD due to low semmns value
In-reply-to: <CA+hUKGKumYUweDKnF5S1Y_jKxMa94w_q8=j8-xDdhOgxcaVCiQ@mail.gmail.com>
References: <db2773a2-aca0-43d0-99c1-060efcd9954e@gmail.com> <CA+hUKGKumYUweDKnF5S1Y_jKxMa94w_q8=j8-xDdhOgxcaVCiQ@mail.gmail.com>
Comments: In-reply-to Thomas Munro <thomas.munro@gmail.com>
	message dated "Tue, 17 Dec 2024 16:11:37 +1300"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <2159465.1734409741.1@sss.pgh.pa.us>
Date: Mon, 16 Dec 2024 23:29:01 -0500
Message-ID: <2159466.1734409741@sss.pgh.pa.us>
Archived-At: <https://www.postgresql.org/message-id/2159466.1734409741%40sss.pgh.pa.us>
Precedence: bulk

Thomas Munro <thomas.munro@gmail.com> writes:
> Whenever I run into this, or my Mac requires manual ipcrm to clean up
> leaked SysV kernel junk, I rebase my patch for sema_kind = 'futex'.
> Here it goes.  It could be updated to support NetBSD I believe, but I
> didn't try as its futex stuff came out later.

FWIW, I looked at a nearby NetBSD 10.0 machine.  It has
/usr/include/sys/futex.h, which includes this enticing comment:

/*
 * Definitions for the __futex(2) synchronization primitive.
 *
 * These definitions are intended to be ABI-compatible with the
 * Linux futex(2) system call.
 */

However, the complete lack of any user-level documentation makes
me misdoubt the extent of their commitment to this :-(

I have the same concern about depending on undocumented macOS
APIs.  Other than that, getting off of SysV semaphores would be
a nice thing to do.

			regards, tom lane