From: Eli Zaretskii <eliz@gnu.org>
To: dick.r.chiang@gmail.com
Cc: 36609@debbugs.gnu.org
Subject: bug#36609: 27.0.50; Possible race-condition in threading implementation
Date: Sun, 20 Jun 2021 18:53:40 +0300 [thread overview]
Message-ID: <834kdsv8fv.fsf@gnu.org> (raw)
In-Reply-To: <87fsxcws72.fsf@dick> (dick.r.chiang@gmail.com)
> From: dick.r.chiang@gmail.com
> Cc: 36609@debbugs.gnu.org
> Date: Sun, 20 Jun 2021 10:01:37 -0400
>
> Yes! If you just add a negation to the __atomic_sub_fetch call
You mean, use the patch below instead?
> this passes all the MREs.
Thanks, will install soon.
> It's not clear how you want to deal with the #else GNUC_PREREQ (4, 7, 0).
By hoping no one uses this and expects threads to be stable enough
under GTK.
diff --git a/src/xgselect.c b/src/xgselect.c
index 0d91d55bad..92b118b955 100644
--- a/src/xgselect.c
+++ b/src/xgselect.c
@@ -34,12 +34,27 @@ static GMainContext *glib_main_context;
void release_select_lock (void)
{
+#if GNUC_PREREQ (4, 7, 0)
+ if (__atomic_sub_fetch (&threads_holding_glib_lock, 1, __ATOMIC_ACQ_REL) == 0)
+ g_main_context_release (glib_main_context);
+#else
if (--threads_holding_glib_lock == 0)
g_main_context_release (glib_main_context);
+#endif
}
static void acquire_select_lock (GMainContext *context)
{
+#if GNUC_PREREQ (4, 7, 0)
+ if (__atomic_fetch_add (&threads_holding_glib_lock, 1, __ATOMIC_ACQ_REL) == 0)
+ {
+ glib_main_context = context;
+ while (!g_main_context_acquire (context))
+ {
+ /* Spin. */
+ }
+ }
+#else
if (threads_holding_glib_lock++ == 0)
{
glib_main_context = context;
@@ -48,6 +63,7 @@ static void acquire_select_lock (GMainContext *context)
/* Spin. */
}
}
+#endif
}
/* `xg_select' is a `pselect' replacement. Why do we need a separate function?
next prev parent reply other threads:[~2021-06-20 15:53 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-11 20:51 bug#36609: 27.0.50; Possible race-condition in threading implementation Andreas Politz
2019-07-12 7:47 ` Eli Zaretskii
2019-07-12 8:05 ` Eli Zaretskii
2019-07-12 9:02 ` Pip Cet
2019-07-12 12:42 ` Eli Zaretskii
2019-07-12 12:57 ` Pip Cet
2019-07-12 13:31 ` Eli Zaretskii
2019-07-12 13:51 ` Pip Cet
2019-07-12 15:05 ` Eli Zaretskii
2019-07-12 18:06 ` Pip Cet
2019-07-12 18:27 ` Eli Zaretskii
2019-07-12 18:34 ` Eli Zaretskii
2019-07-12 19:24 ` Pip Cet
2019-07-12 19:57 ` Eli Zaretskii
2019-07-13 14:37 ` Pip Cet
2019-07-13 15:03 ` Eli Zaretskii
2019-07-13 15:13 ` Eli Zaretskii
2019-07-13 15:54 ` Eli Zaretskii
2019-07-13 15:57 ` Pip Cet
2019-07-13 16:02 ` Eli Zaretskii
2019-07-13 18:17 ` Pip Cet
2020-08-21 12:57 ` Lars Ingebrigtsen
2019-07-13 15:04 ` Andreas Politz
2019-07-12 12:44 ` Pip Cet
2019-07-12 12:55 ` Eli Zaretskii
2019-07-12 13:40 ` Pip Cet
2019-07-12 13:51 ` Eli Zaretskii
2019-07-12 14:34 ` Pip Cet
2019-07-12 15:02 ` Eli Zaretskii
2019-07-12 19:30 ` Pip Cet
2019-07-13 6:50 ` Eli Zaretskii
2021-06-06 15:50 ` dick.r.chiang
[not found] ` <87fsxv8182.fsf@dick>
2021-06-06 16:35 ` Eli Zaretskii
2021-06-06 19:10 ` dick.r.chiang
2021-06-06 19:27 ` Eli Zaretskii
2021-06-09 21:40 ` dick.r.chiang
2021-06-10 6:46 ` Eli Zaretskii
2021-06-10 11:52 ` dick.r.chiang
2021-06-10 14:18 ` Eli Zaretskii
2021-06-10 14:55 ` dick.r.chiang
2021-06-10 15:04 ` Eli Zaretskii
2021-06-10 21:36 ` dick.r.chiang
2021-06-11 6:00 ` Eli Zaretskii
2021-06-19 17:53 ` Eli Zaretskii
2021-06-19 19:14 ` dick.r.chiang
2021-06-19 19:18 ` Eli Zaretskii
2021-06-19 21:12 ` dick.r.chiang
2021-06-20 11:39 ` Eli Zaretskii
2021-06-20 14:01 ` dick.r.chiang
2021-06-20 15:53 ` Eli Zaretskii [this message]
2021-06-25 13:54 ` Eli Zaretskii
2021-06-10 15:35 ` Andreas Schwab
2021-06-10 15:39 ` Eli Zaretskii
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
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=834kdsv8fv.fsf@gnu.org \
--to=eliz@gnu.org \
--cc=36609@debbugs.gnu.org \
--cc=dick.r.chiang@gmail.com \
/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.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
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).