file-backend: avoid deadlock when portal op is canceledmcatanzaro/cancellable-deadlock

Calling g_cancellable_disconnect() inside a cancelled handler is a
guaranteed deadlock. Cancellables should only be canceled once, so we
don't need to worry about a second cancellation occurring. I think it's
sufficent to disconnect when the InitClosure is freed.

Fixes #86

1 files changed, 10 insertions, 3 deletions

diff --git a/libsecret/secret-file-backend.c b/libsecret/secret-file-backend.c
index 12738df..dd18a5b 100644
--- a/libsecret/secret-file-backend.c
+++ b/libsecret/secret-file-backend.c
@@ -206,6 +206,7 @@ typedef struct {
 	GDBusConnection *connection;
 	gchar *request_path;
 	guint portal_signal_id;
+	GCancellable *cancellable;
 	gulong cancellable_signal_id;
 } InitClosure;
 
@@ -218,6 +219,14 @@ init_closure_free (gpointer data)
 	g_clear_pointer (&init->buffer, egg_secure_free);
 	g_clear_object (&init->connection);
 	g_clear_pointer (&init->request_path, g_free);
+	if (init->cancellable_signal_id) {
+		g_cancellable_disconnect (init->cancellable, init->cancellable_signal_id);
+		init->cancellable_signal_id = 0;
+	}
+	/* Note: do not cancel the cancellable here! That's for the API user to
+	 * do. We're just keeping track of it here so we can disconnect.
+	 */
+	g_clear_object (&init->cancellable);
 	g_free (init);
 }
 
@@ -352,9 +361,6 @@ on_portal_cancel (GCancellable *cancellable,
 				cancellable,
 				on_portal_request_close,
 				task);
-
-	g_cancellable_disconnect (cancellable, init->cancellable_signal_id);
-	init->cancellable_signal_id = 0;
 }
 
 static void
@@ -575,6 +581,7 @@ secret_file_backend_real_init_async (GAsyncInitable *initable,
 		init = g_new0 (InitClosure, 1);
 		init->io_priority = io_priority;
 		init->file = file;
+		init->cancellable = g_object_ref (cancellable);
 		g_task_set_task_data (task, init, init_closure_free);
 		g_bus_get (G_BUS_TYPE_SESSION, cancellable, on_bus_get, task);
 	} else {