[gnome-remote-desktop] rdp: Add API to tear down channels during a session

[Jonas Ådahl <jadahl src gnome org>]

commit 7751306a018f9576e37eb85813f3ca97409e73ef
Author: Pascal Nowack <Pascal Nowack gmx de>
Date:   Tue May 31 09:44:55 2022 +0200

    rdp: Add API to tear down channels during a session
    
    When during a session a channel is not needed any more, it should not
    waste resources.
    This will especially be the case for the AUDIO_PLAYBACK_DVC channel, as
    the user might disable that channel on the client side.
    Since opening a dynamic channel may not imply, that the client supports
    that channel, add an API to tear down channels during a session.
    
    This API will be used in the next commits for the AUDIO_PLAYBACK_DVC
    channel.

 src/grd-rdp-private.h |  2 ++
 src/grd-session-rdp.c | 30 +++++++++++++++++++++++++-----
 src/grd-session-rdp.h |  8 ++++++++
 3 files changed, 35 insertions(+), 5 deletions(-)
---
diff --git a/src/grd-rdp-private.h b/src/grd-rdp-private.h
index 9faebef4..f2a885a8 100644
--- a/src/grd-rdp-private.h
+++ b/src/grd-rdp-private.h
@@ -41,6 +41,8 @@ typedef struct _RdpPeerContext
   /* Virtual Channel Manager */
   HANDLE vcm;
 
+  GMutex channel_mutex;
+
   GrdClipboardRdp *clipboard_rdp;
   GrdRdpDisplayControl *display_control;
   GrdRdpGraphicsPipeline *graphics_pipeline;
diff --git a/src/grd-session-rdp.c b/src/grd-session-rdp.c
index 7f3667ba..63e0bfc5 100644
--- a/src/grd-session-rdp.c
+++ b/src/grd-session-rdp.c
@@ -650,6 +650,23 @@ grd_session_rdp_notify_error (GrdSessionRdp      *session_rdp,
   maybe_queue_close_session_idle (session_rdp);
 }
 
+void
+grd_session_rdp_tear_down_channel (GrdSessionRdp *session_rdp,
+                                   GrdRdpChannel  channel)
+{
+  freerdp_peer *peer = session_rdp->peer;
+  RdpPeerContext *rdp_peer_context = (RdpPeerContext *) peer->context;
+
+  g_mutex_lock (&rdp_peer_context->channel_mutex);
+  switch (channel)
+    {
+    case GRD_RDP_CHANNEL_NONE:
+      g_assert_not_reached ();
+      break;
+    }
+  g_mutex_unlock (&rdp_peer_context->channel_mutex);
+}
+
 static void
 handle_client_gone (GrdSessionRdp *session_rdp)
 {
@@ -1827,6 +1844,8 @@ rdp_peer_context_free (freerdp_peer   *peer,
     }
 
   g_clear_pointer (&rdp_peer_context->rfx_context, rfx_context_free);
+
+  g_mutex_clear (&rdp_peer_context->channel_mutex);
 }
 
 static BOOL
@@ -1837,10 +1856,13 @@ rdp_peer_context_new (freerdp_peer   *peer,
 
   rdp_peer_context->frame_id = 0;
 
+  g_mutex_init (&rdp_peer_context->channel_mutex);
+
   rdp_peer_context->rfx_context = rfx_context_new (TRUE);
   if (!rdp_peer_context->rfx_context)
     {
       g_warning ("[RDP] Failed to create RFX context");
+      rdp_peer_context_free (peer, rdp_peer_context);
       return FALSE;
     }
   rfx_context_set_pixel_format (rdp_peer_context->rfx_context,
@@ -1994,7 +2016,6 @@ socket_thread_func (gpointer data)
   GrdSessionRdp *session_rdp = data;
   freerdp_peer *peer;
   RdpPeerContext *rdp_peer_context;
-  rdpSettings *rdp_settings;
   HANDLE vcm;
   HANDLE channel_event;
   HANDLE events[32];
@@ -2006,7 +2027,6 @@ socket_thread_func (gpointer data)
 
   peer = session_rdp->peer;
   rdp_peer_context = (RdpPeerContext *) peer->context;
-  rdp_settings = peer->settings;
   vcm = rdp_peer_context->vcm;
   channel_event = WTSVirtualChannelManagerGetEventHandle (vcm);
 
@@ -2066,13 +2086,13 @@ socket_thread_func (gpointer data)
               SetEvent (channel_event);
               break;
             case DRDYNVC_STATE_READY:
+              g_mutex_lock (&rdp_peer_context->channel_mutex);
               graphics_pipeline = rdp_peer_context->graphics_pipeline;
               display_control = rdp_peer_context->display_control;
 
-              if (rdp_settings->SupportGraphicsPipeline)
-                grd_rdp_graphics_pipeline_maybe_init (graphics_pipeline);
-
+              grd_rdp_graphics_pipeline_maybe_init (graphics_pipeline);
               grd_rdp_display_control_maybe_init (display_control);
+              g_mutex_unlock (&rdp_peer_context->channel_mutex);
               break;
             }
 
diff --git a/src/grd-session-rdp.h b/src/grd-session-rdp.h
index 0beaa565..9ff709f0 100644
--- a/src/grd-session-rdp.h
+++ b/src/grd-session-rdp.h
@@ -40,6 +40,11 @@ typedef enum _GrdSessionRdpError
   GRD_SESSION_RDP_ERROR_GRAPHICS_SUBSYSTEM_FAILED,
 } GrdSessionRdpError;
 
+typedef enum _GrdRdpChannel
+{
+  GRD_RDP_CHANNEL_NONE,
+} GrdRdpChannel;
+
 GrdSessionRdp *grd_session_rdp_new (GrdRdpServer      *rdp_server,
                                     GSocketConnection *connection,
                                     GrdHwAccelNvidia  *hwaccel_nvidia);
@@ -47,6 +52,9 @@ GrdSessionRdp *grd_session_rdp_new (GrdRdpServer      *rdp_server,
 void grd_session_rdp_notify_error (GrdSessionRdp      *session_rdp,
                                    GrdSessionRdpError  error_info);
 
+void grd_session_rdp_tear_down_channel (GrdSessionRdp *session_rdp,
+                                        GrdRdpChannel  channel);
+
 void grd_session_rdp_submit_new_monitor_config (GrdSessionRdp       *session_rdp,
                                                 GrdRdpMonitorConfig *new_monitor_config);