[wing] namedpipelistener: handle multiple clients connecting to the same pipe

[Ignacio Casal Quinteiro <icq src gnome org>]

commit d150f8a153eff37b04fd6a4b9f94a2061e8731f2
Author: Ignacio Casal Quinteiro <icq gnome org>
Date:   Thu Jul 14 13:35:44 2016 +0200

    namedpipelistener: handle multiple clients connecting to the same pipe
    
    In the moment that we get a connection to the pipe we need to
    create another so another client can connect to it otherwise
    we were getting an error every time a second client was connecting
    to the pipe or that the listener was trying to accept a pipe
    the second time.

 wing/wingnamedpipelistener.c |  147 +++++++++++++++++++++++++-----------------
 1 files changed, 87 insertions(+), 60 deletions(-)
---
diff --git a/wing/wingnamedpipelistener.c b/wing/wingnamedpipelistener.c
index 103d7ff..4fe21a5 100644
--- a/wing/wingnamedpipelistener.c
+++ b/wing/wingnamedpipelistener.c
@@ -28,6 +28,7 @@
 typedef struct
 {
   gchar *pipe_name;
+  gunichar2 *pipe_namew;
   HANDLE handle;
   OVERLAPPED overlapped;
   GObject *source_object;
@@ -46,14 +47,14 @@ static GQuark source_quark = 0;
 
 static PipeData *
 pipe_data_new (const gchar *pipe_name,
-               HANDLE       handle,
                GObject     *source_object)
 {
   PipeData *data;
 
   data = g_slice_new0 (PipeData);
   data->pipe_name = g_strdup (pipe_name);
-  data->handle = handle;
+  data->pipe_namew = g_utf8_to_utf16 (pipe_name, -1, NULL, NULL, NULL);
+  data->handle = INVALID_HANDLE_VALUE;
   data->overlapped.hEvent = CreateEvent (NULL, /* default security attribute */
                                          TRUE, /* manual-reset event */
                                          TRUE, /* initial state = signaled */
@@ -68,6 +69,7 @@ static void
 pipe_data_free (PipeData *data)
 {
   g_free (data->pipe_name);
+  g_free (data->pipe_namew);
   if (data->handle != INVALID_HANDLE_VALUE)
     CloseHandle (data->handle);
   CloseHandle (data->overlapped.hEvent);
@@ -126,56 +128,25 @@ wing_named_pipe_listener_new (void)
   return g_object_new (WING_TYPE_NAMED_PIPE_LISTENER, NULL);
 }
 
-/**
- * wing_named_pipe_listener_add_named_pipe:
- * @listener: a #WingNamedPipeListener.
- * @pipe_name: a name for the pipe.
- * @source_object: (allow-none): Optional #GObject identifying this source
- * @error: #GError for error reporting, or %NULL to ignore.
- *
- * Adds @named_pipe to the set of named pipes that we try to accept clients
- * from.
- *
- * @source_object will be passed out in the various calls
- * to accept to identify this particular source, which is
- * useful if you're listening on multiple pipes and do
- * different things depending on what pipe is connected to.
- *
- * Returns: %TRUE on success, %FALSE on error.
- *
- * Since: 2.48
- */
-gboolean
-wing_named_pipe_listener_add_named_pipe (WingNamedPipeListener  *listener,
-                                         const gchar            *pipe_name,
-                                         GObject                *source_object,
-                                         GError                **error)
+static gboolean
+create_pipe_from_pipe_data (PipeData  *pipe_data,
+                            GError   **error)
 {
-  WingNamedPipeListenerPrivate *priv;
-  gunichar2 *pipe_namew;
-  PipeData *pipe_data;
-  HANDLE handle;
-
-  g_return_val_if_fail (WING_IS_NAMED_PIPE_LISTENER (listener), FALSE);
-  g_return_val_if_fail (pipe_name != NULL, FALSE);
-
-  priv = wing_named_pipe_listener_get_instance_private (listener);
-
-  pipe_namew = g_utf8_to_utf16 (pipe_name, -1, NULL, NULL, NULL);
-
-  handle = CreateNamedPipeW (pipe_namew,
-                             PIPE_ACCESS_DUPLEX |
-                             FILE_FLAG_OVERLAPPED,
-                             PIPE_TYPE_BYTE |
-                             PIPE_READMODE_BYTE |
-                             PIPE_WAIT,
-                             PIPE_UNLIMITED_INSTANCES,
-                             DEFAULT_PIPE_BUF_SIZE,
-                             DEFAULT_PIPE_BUF_SIZE,
-                             0, NULL);
-  g_free (pipe_namew);
-
-  if (handle == INVALID_HANDLE_VALUE)
+  /* Set event as signaled */
+  SetEvent(pipe_data->overlapped.hEvent);
+
+  pipe_data->handle = CreateNamedPipeW (pipe_data->pipe_namew,
+                                        PIPE_ACCESS_DUPLEX |
+                                        FILE_FLAG_OVERLAPPED,
+                                        PIPE_TYPE_BYTE |
+                                        PIPE_READMODE_BYTE |
+                                        PIPE_WAIT,
+                                        PIPE_UNLIMITED_INSTANCES,
+                                        DEFAULT_PIPE_BUF_SIZE,
+                                        DEFAULT_PIPE_BUF_SIZE,
+                                        0, NULL);
+
+  if (pipe_data->handle == INVALID_HANDLE_VALUE)
     {
       int errsv = GetLastError ();
       gchar *emsg = g_win32_error_message (errsv);
@@ -184,15 +155,13 @@ wing_named_pipe_listener_add_named_pipe (WingNamedPipeListener  *listener,
                    G_IO_ERROR,
                    g_io_error_from_win32_error (errsv),
                    "Error creating named pipe '%s': %s",
-                   pipe_name, emsg);
+                   pipe_data->pipe_name, emsg);
       g_free (emsg);
 
       return FALSE;
     }
 
-  pipe_data = pipe_data_new (pipe_name, handle, source_object);
-
-  if (!ConnectNamedPipe (handle, &pipe_data->overlapped))
+  if (!ConnectNamedPipe (pipe_data->handle, &pipe_data->overlapped))
     {
       switch (GetLastError ())
       {
@@ -209,15 +178,57 @@ wing_named_pipe_listener_add_named_pipe (WingNamedPipeListener  *listener,
           g_set_error (error,
                        G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
                        "Failed to connect named pipe '%s': %s",
-                       pipe_name, emsg);
+                       pipe_data->pipe_name, emsg);
           g_free (emsg);
-          pipe_data_free (pipe_data);
 
           return FALSE;
         }
       }
     }
 
+  return TRUE;
+}
+
+/**
+ * wing_named_pipe_listener_add_named_pipe:
+ * @listener: a #WingNamedPipeListener.
+ * @pipe_name: a name for the pipe.
+ * @source_object: (allow-none): Optional #GObject identifying this source
+ * @error: #GError for error reporting, or %NULL to ignore.
+ *
+ * Adds @named_pipe to the set of named pipes that we try to accept clients
+ * from.
+ *
+ * @source_object will be passed out in the various calls
+ * to accept to identify this particular source, which is
+ * useful if you're listening on multiple pipes and do
+ * different things depending on what pipe is connected to.
+ *
+ * Returns: %TRUE on success, %FALSE on error.
+ *
+ * Since: 2.48
+ */
+gboolean
+wing_named_pipe_listener_add_named_pipe (WingNamedPipeListener  *listener,
+                                         const gchar            *pipe_name,
+                                         GObject                *source_object,
+                                         GError                **error)
+{
+  WingNamedPipeListenerPrivate *priv;
+  PipeData *pipe_data;
+
+  g_return_val_if_fail (WING_IS_NAMED_PIPE_LISTENER (listener), FALSE);
+  g_return_val_if_fail (pipe_name != NULL, FALSE);
+
+  priv = wing_named_pipe_listener_get_instance_private (listener);
+
+  pipe_data = pipe_data_new (pipe_name, source_object);
+  if (!create_pipe_from_pipe_data (pipe_data, error))
+    {
+      pipe_data_free (pipe_data);
+      return FALSE;
+    }
+
   g_ptr_array_add (priv->named_pipes, pipe_data);
 
   return TRUE;
@@ -265,6 +276,7 @@ connect_ready (HANDLE   handle,
   else
     {
       WingNamedPipeConnection *connection;
+      GError *error = NULL;
 
       if (pipe_data->source_object != NULL)
         g_object_set_qdata_full (G_OBJECT (task),
@@ -274,9 +286,17 @@ connect_ready (HANDLE   handle,
 
       connection = g_object_new (WING_TYPE_NAMED_PIPE_CONNECTION,
                                  "handle", pipe_data->handle,
-                                 "close-handle", FALSE,
+                                 "close-handle", TRUE,
                                  NULL);
-      g_task_return_pointer (task, connection, g_object_unref);
+
+      /* Put another pipe to listen so more clients can already connect */
+      if (!create_pipe_from_pipe_data (pipe_data, &error))
+        {
+          g_object_unref (connection);
+          g_task_return_error (task, error);
+        }
+      else
+        g_task_return_pointer (task, connection, g_object_unref);
     }
 
   g_object_unref (task);
@@ -469,11 +489,18 @@ wing_named_pipe_listener_accept (WingNamedPipeListener  *listener,
     {
       connection = g_object_new (WING_TYPE_NAMED_PIPE_CONNECTION,
                                  "handle", pipe_data->handle,
-                                 "close-handle", FALSE,
+                                 "close-handle", TRUE,
                                  NULL);
 
       if (source_object)
         *source_object = pipe_data->source_object;
+
+      /* Put another pipe to listen so more clients can already connect */
+      if (!create_pipe_from_pipe_data (pipe_data, error))
+        {
+          g_object_unref (connection);
+          connection = NULL;
+        }
     }
 
   return connection;