From 218b298a1b8958e9313a460b674238d76191a3ae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marco=20Trevisan=20=28Trevi=C3=B1o=29?= <mail@3v1n0.net>
Date: Thu, 30 Jan 2025 19:10:40 +0100
Subject: [PATCH] gio/gfilemonitor: Use atomic API to get / store cancelled
 state

The cancelled state may be set and read by different threads, so ensure
that it's stored and managed in an atomic way.

We could in fact end up check for `g_file_monitor_is_cancelled()` in a
thread and `g_file_monitor_cancel()` or `g_file_monitor_emit_event` in
in another one.
---
 gio/gfilemonitor.c    | 14 +++++---------
 gio/tests/meson.build |  6 +++++-
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/gio/gfilemonitor.c b/gio/gfilemonitor.c
index bcfa3636f..d89c54e17 100644
--- a/gio/gfilemonitor.c
+++ b/gio/gfilemonitor.c
@@ -25,6 +25,7 @@
 
 #include "gfilemonitor.h"
 #include "gioenumtypes.h"
+#include "glib.h"
 #include "gmarshal-internal.h"
 #include "gfile.h"
 #include "gvfs.h"
@@ -52,7 +53,7 @@
 
 struct _GFileMonitorPrivate
 {
-  gboolean cancelled;
+  int cancelled; /* atomic */
 };
 
 G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GFileMonitor, g_file_monitor, G_TYPE_OBJECT)
@@ -219,13 +220,9 @@ g_file_monitor_class_init (GFileMonitorClass *klass)
 gboolean
 g_file_monitor_is_cancelled (GFileMonitor *monitor)
 {
-  gboolean res;
-
   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 
-  res = monitor->priv->cancelled;
-
-  return res;
+  return g_atomic_int_get (&monitor->priv->cancelled);
 }
 
 /**
@@ -241,11 +238,10 @@ g_file_monitor_cancel (GFileMonitor *monitor)
 {
   g_return_val_if_fail (G_IS_FILE_MONITOR (monitor), FALSE);
 
-  if (!monitor->priv->cancelled)
+  if (!g_atomic_int_exchange (&monitor->priv->cancelled, TRUE))
     {
       G_FILE_MONITOR_GET_CLASS (monitor)->cancel (monitor);
 
-      monitor->priv->cancelled = TRUE;
       g_object_notify (G_OBJECT (monitor), "cancelled");
     }
 
@@ -293,7 +289,7 @@ g_file_monitor_emit_event (GFileMonitor      *monitor,
   g_return_if_fail (G_IS_FILE (child));
   g_return_if_fail (!other_file || G_IS_FILE (other_file));
 
-  if (monitor->priv->cancelled)
+  if (g_atomic_int_get (&monitor->priv->cancelled))
     return;
 
   g_signal_emit (monitor, g_file_monitor_changed_signal, 0, child, other_file, event_type);
diff --git a/gio/tests/meson.build b/gio/tests/meson.build
index 43c1bfe34..23fd5a208 100644
--- a/gio/tests/meson.build
+++ b/gio/tests/meson.build
@@ -134,7 +134,11 @@ gio_tests = {
   'vfs' : {},
   'volumemonitor' : {},
   'glistmodel' : {},
-  'testfilemonitor' : {'suite' : ['slow', 'flaky']},
+  'testfilemonitor' : {
+    'suite' : ['slow'],
+    # FIXME: https://gitlab.gnome.org/GNOME/glib/-/issues/1392
+    'can_fail' : host_system in ['darwin'],
+  },
   'thumbnail-verification' : {},
   'tls-certificate' : {'extra_sources' : ['gtesttlsbackend.c']},
   'tls-interaction' : {'extra_sources' : ['gtesttlsbackend.c']},