From: Guilherme Janczak <guilherme.janczak@yandex.com>
To: perfbook@vger.kernel.org
Subject: [PATCH] signal handlers: volatile sigatomic_t, not volatile OR sigatomic_t
Date: Wed, 20 Mar 2024 20:25:23 +0000 [thread overview]
Message-ID: <wehwhnxba7wraxuevaqvuutug4k4orzn4yxrvlm2bcva5qpax6@ctvbjzt5dlqb> (raw)
Variables shared with signal handlers must be of type `volatile
sigatomic_t`, not `volatile` or `sigatomic_t` as the current text says,
according to a C11 draft:
When ... interrupted by ... a signal, values of objects that are
neither lock-free atomic objects nor of type volatile sig_atomic_t
are unspecified.
Ref: https://www.iso-9899.info/n1570.html#5.1.2.3p5
Signed-off-by: Guilherme Janczak <guilherme.janczak@yandex.com>
---
memorder/memorder.tex | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/memorder/memorder.tex b/memorder/memorder.tex
index 5c50d42d..873c3424 100644
--- a/memorder/memorder.tex
+++ b/memorder/memorder.tex
@@ -1317,8 +1317,8 @@ from the viewpoint of the interrupted thread, at least at the
assembly-language level.
However, the C and C++ languages do not define the results of handlers
and interrupted threads sharing plain variables.
-Instead, such shared variables must be \co{sig_atomic_t}, lock-free
-atomics, or \co{volatile}.
+Instead, such shared variables must be \co{volatile sig_atomic_t} or
+lock-free atomics.
On the other hand, because the handler executes within the interrupted
thread's context, the memory ordering used to synchronize communication
--
2.42.0
next reply other threads:[~2024-03-20 20:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-20 20:25 Guilherme Janczak [this message]
2024-03-20 20:44 ` [PATCH] signal handlers: volatile sigatomic_t, not volatile OR sigatomic_t Elad Lahav
2024-03-20 22:26 ` Guilherme Janczak
2024-03-20 23:07 ` Paul E. McKenney
2024-03-28 16:30 ` Elad Lahav
2024-03-29 1:23 ` Akira Yokosawa
[not found] ` <r63f5f54bb6cilp542vw52ctpjnjbik5pbfrsswvjzccipokgg@c2kdkpmxbfue>
2024-03-20 23:05 ` Elad Lahav
2024-03-20 23:20 ` Elad Lahav
2024-03-21 0:34 ` Guilherme Janczak
2024-03-21 1:03 ` Elad Lahav
2024-03-21 1:19 ` Elad Lahav
2024-03-20 23:02 ` Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=wehwhnxba7wraxuevaqvuutug4k4orzn4yxrvlm2bcva5qpax6@ctvbjzt5dlqb \
--to=guilherme.janczak@yandex.com \
--cc=perfbook@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).