[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
master 6e0bff0: Fix race conditions between Lisp threads in GTK builds
From: |
Eli Zaretskii |
Subject: |
master 6e0bff0: Fix race conditions between Lisp threads in GTK builds |
Date: |
Fri, 25 Jun 2021 09:53:53 -0400 (EDT) |
branch: master
commit 6e0bff0296b08fe96b7060f8d10eaa393fcb7bd4
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>
Fix race conditions between Lisp threads in GTK builds
* src/xgselect.c (release_select_lock, acquire_select_lock)
[GCC >= 4.7.0]: Use '__atomic' builtins to prevent races between
threads in accessing 'threads_holding_glib_lock'. Reported by
<dick.r.chiang@gmail.com>. (Bug#36609)
---
src/xgselect.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/src/xgselect.c b/src/xgselect.c
index 0d91d55..92b118b 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?
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- master 6e0bff0: Fix race conditions between Lisp threads in GTK builds,
Eli Zaretskii <=