streams: add private 'async close via threads' API

Add an internal helper to find out if close_async() is implemented via
threads using the default implementation in the base class.

We will use this to decide if we should do a 'pure async' close of a
GIOStream or not.

https://bugzilla.gnome.org/show_bug.cgi?id=741630

1 files changed, 19 insertions, 0 deletions

diff --git a/gio/goutputstream.c b/gio/goutputstream.c
index ea05b41bf..035465db3 100644
--- a/gio/goutputstream.c
+++ b/gio/goutputstream.c
@@ -1705,6 +1705,25 @@ g_output_stream_async_write_is_via_threads (GOutputStream *stream)
         g_pollable_output_stream_can_poll (G_POLLABLE_OUTPUT_STREAM (stream))));
 }
 
+/*< internal >
+ * g_output_stream_async_close_is_via_threads:
+ * @stream: output stream
+ *
+ * Checks if an output stream's close_async function uses threads.
+ *
+ * Returns: %TRUE if @stream's close_async function uses threads.
+ **/
+gboolean
+g_output_stream_async_close_is_via_threads (GOutputStream *stream)
+{
+  GOutputStreamClass *class;
+
+  g_return_val_if_fail (G_IS_OUTPUT_STREAM (stream), FALSE);
+
+  class = G_OUTPUT_STREAM_GET_CLASS (stream);
+
+  return class->close_async == g_output_stream_real_close_async;
+}
 
 /********************************************
  *   Default implementation of async ops    *