Bug 278459

Summary:	Add pthread_sigqueue()
Product:	Base System	Reporter:	vini.ipsmaker
Component:	kern	Assignee:	Konstantin Belousov <kib>
Status:	Closed FIXED
Severity:	Affects Only Me	CC:	emaste, kib
Priority:	---
Version:	14.0-RELEASE
Hardware:	Any
OS:	Any

Description vini.ipsmaker 2024-04-19 13:07:21 UTC

Linux and Solaris 11 offer pthread_sigqueue(3) that is to sigqueue(2) what pthread_kill(3) is to kill(2). I've been using pthread_sigqueue() on my own software to offer different "cancellation paths". To illustrate my need, here is the piece of the code that I want to be cancellable:

https://gitlab.com/emilua/emilua/-/blob/v0.7.1/src/file.cpp#L520-532

As you can see, I use setjmp() for a switch expression that will allow me to jump to different cancel-handling paths.

Here's the cancellation type-1: https://gitlab.com/emilua/emilua/-/blob/v0.7.1/src/file.cpp#L463

Here's cancellation type-2: https://gitlab.com/emilua/emilua/-/blob/v0.7.1/src/file.cpp#L93

Both cancellators just use pthread_sigqueue(). Cancellator type-1 will use sigval::sival_int=1 and cancellator type-2 will use sigval::sival_int=2. The sighandler (SA_SIGINFO) will use this value as an argument to longjmp(): https://gitlab.com/emilua/emilua/-/blob/v0.7.1/src/core.cpp#L756

Can FreeBSD have pthread_sigqueue() as in Linux and Solaris?

Comment 1 Konstantin Belousov freebsd_committer

2024-04-19 15:39:26 UTC

https://reviews.freebsd.org/D44867

Comment 2 commit-hook freebsd_committer

2024-04-23 16:53:03 UTC

A commit in branch main references this bug:

URL: https://cgit.FreeBSD.org/src/commit/?id=220aa0f450409948b869237e5c4505f992c913ce

commit 220aa0f450409948b869237e5c4505f992c913ce
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2024-04-19 14:40:40 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2024-04-23 16:51:22 +0000

    libthr: add pthread_sigqueue(3)

    PR:     278459
    Reviewed by:    markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D44867

 include/pthread.h                      |  7 +++
 lib/libthr/pthread.map                 |  4 ++
 lib/libthr/thread/Makefile.inc         |  1 +
 lib/libthr/thread/thr_private.h        |  1 +
 lib/libthr/thread/thr_sigqueue.c (new) | 79 ++++++++++++++++++++++++++++++++++
 5 files changed, 92 insertions(+)

Comment 3 commit-hook freebsd_committer

2024-04-30 00:49:24 UTC

A commit in branch stable/14 references this bug:

URL: https://cgit.FreeBSD.org/src/commit/?id=e449481bee5fd08d4342156696eb4a6eef531ef0

commit e449481bee5fd08d4342156696eb4a6eef531ef0
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2024-04-19 14:40:40 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2024-04-30 00:48:09 +0000

    libthr: add pthread_sigqueue(3)

    PR:     278459

    (cherry picked from commit 220aa0f450409948b869237e5c4505f992c913ce)

 include/pthread.h                      |  7 +++
 lib/libthr/pthread.map                 |  4 ++
 lib/libthr/thread/Makefile.inc         |  1 +
 lib/libthr/thread/thr_private.h        |  1 +
 lib/libthr/thread/thr_sigqueue.c (new) | 79 ++++++++++++++++++++++++++++++++++
 5 files changed, 92 insertions(+)