xfixes: Add ClientDisconnectMode

The Xserver itself is capable of terminating itself once all X11 clients
are gone, yet in a typical full session, there are a number of X11
clients running continuously (e.g. the Xsettings daemon, IBus, etc.).

Those always-running clients will prevent the Xserver from terminating,
because the actual number of X11 clients will never drop to 0.

To solve this issue directly at the Xserver level, this add new entries
to the XFixes extension to let the X11 clients themselves specify the
disconnect mode they expect.

Typically, those X11 daemon clients would specify the disconnect mode
XFixesClientDisconnectFlagTerminate to let the Xserver know that they
should not be accounted for when checking the remaining clients prior
to terminate.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>

4 files changed, 104 insertions, 3 deletions

diff --git a/fixesproto.pc.in b/fixesproto.pc.in
index 5274728..05917d8 100644
--- a/fixesproto.pc.in
+++ b/fixesproto.pc.in
@@ -3,6 +3,6 @@ includedir=@includedir@
 
 Name: FixesProto
 Description: X Fixes extension headers
-Version: 5.0
+Version: 6.0
 Cflags: -I${includedir}
 Requires: xextproto >= 7.0.99.1
diff --git a/fixesproto.txt b/fixesproto.txt
index ff083bc..28a6270 100644
--- a/fixesproto.txt
+++ b/fixesproto.txt
@@ -640,6 +640,63 @@ DestroyPointerBarrier
 
 	Errors: Barrier 
 
+************* XFIXES VERSION 6 OR BETTER ***********
+
+13. Disconnect mode
+
+The X11 server is capable of terminating itself once all X11 clients are
+gone.
+
+Yet, in a typical user session, there are a number of X11 clients running
+continuously (e.g. Xsettings daemon, IBus, etc.). Those always-running
+clients will prevent the X11 server from terminating, because the actual
+number of X11 clients will never drop to 0.
+
+Disconnect mode allows the X11 clients themselves to specify that they
+should not be accounted for when checking the remaining clients prior
+to terminate the X11 server.
+
+This can be particularly useful for Wayland compositors which are able to
+start Xwayland on demand, as this allows Xwayland to terminate automatically
+when the relevant X11 clients have quit.
+
+13.1 Types
+
+	XFixesClientDisconnectFlags
+
+		XFixesClientDisconnectFlagDefault:	    0
+		XFixesClientDisconnectFlagTerminate:	    1 << 0
+
+	XFixesClientDisconnectFlagDefault is the default behavior for
+	regular clients, i.e. the X11 server won't terminate as long as such
+	clients are still connected.
+
+	XFixesClientDisconnectFlagTerminate indicates to the X11 server that
+	it can ignore the client and terminate itself even though the client
+	is still connected to the X11 server.
+
+13.2 Requests
+
+SetClientDisconnectMode
+
+		disconnect-mode:	    CARD32
+
+	Sets the disconnect mode for the client.
+
+	The disconnect-mode is a bit mask of XFixesClientDisconnectFlags.
+
+
+GetClientDisconnectMode
+
+	Gets the disconnect mode for the client.
+
+		->
+
+		disconnect-mode:	    CARD32
+
+	The disconnect-mode is a bit mask of XFixesClientDisconnectFlags.
+
+
 99. Future compatibility
 
 This extension is not expected to remain fixed.  Future changes will
diff --git a/include/X11/extensions/xfixesproto.h b/include/X11/extensions/xfixesproto.h
index b18b306..96c1b21 100644
--- a/include/X11/extensions/xfixesproto.h
+++ b/include/X11/extensions/xfixesproto.h
@@ -532,6 +532,40 @@ typedef struct {
 
 #define sz_xXFixesDestroyPointerBarrierReq 8
 
+/*************** Version 6.0 ******************/
+
+typedef struct {
+    CARD8   reqType;
+    CARD8   xfixesReqType;
+    CARD16  length;
+    CARD32  disconnect_mode;
+} xXFixesSetClientDisconnectModeReq;
+
+#define sz_xXFixesSetClientDisconnectModeReq    8
+
+typedef struct {
+    CARD8   reqType;
+    CARD8   xfixesReqType;
+    CARD16  length;
+} xXFixesGetClientDisconnectModeReq;
+
+#define sz_xXFixesGetClientDisconnectModeReq    4
+
+typedef struct {
+    BYTE        type;                   /* X_Reply */
+    CARD8       pad0;
+    CARD16      sequenceNumber;
+    CARD32      length;
+    CARD32      disconnect_mode;
+    CARD32      pad1;
+    CARD32      pad2;
+    CARD32      pad3;
+    CARD32      pad4;
+    CARD32      pad5;
+} xXFixesGetClientDisconnectModeReply;
+
+#define sz_xXFixesGetClientDisconnectModeReply	32
+
 #undef Barrier
 #undef Region
 #undef Picture
diff --git a/include/X11/extensions/xfixeswire.h b/include/X11/extensions/xfixeswire.h
index 432349a..f6953e5 100644
--- a/include/X11/extensions/xfixeswire.h
+++ b/include/X11/extensions/xfixeswire.h
@@ -48,7 +48,7 @@
 #define _XFIXESWIRE_H_
 
 #define XFIXES_NAME	"XFIXES"
-#define XFIXES_MAJOR	5
+#define XFIXES_MAJOR	6
 #define XFIXES_MINOR	0
 
 /*************** Version 1 ******************/
@@ -89,8 +89,11 @@
 /*************** Version 5 ******************/
 #define X_XFixesCreatePointerBarrier	    31
 #define X_XFixesDestroyPointerBarrier	    32
+/*************** Version 6 ******************/
+#define X_XFixesSetClientDisconnectMode	    33
+#define X_XFixesGetClientDisconnectMode	    34
 
-#define XFixesNumberRequests		    (X_XFixesDestroyPointerBarrier+1)
+#define XFixesNumberRequests		    (X_XFixesGetClientDisconnectMode+1)
 
 /* Selection events share one event number */
 #define XFixesSelectionNotify		    0
@@ -136,4 +139,11 @@
 #define BarrierNegativeX		    (1L << 2)
 #define BarrierNegativeY		    (1L << 3)
 
+/*************** Version 6 ******************/
+
+/* The default server behaviour */
+#define XFixesClientDisconnectFlagDefault   0
+/* The server may disconnect this client to shut down */
+#define XFixesClientDisconnectFlagTerminate  (1L << 0)
+
 #endif	/* _XFIXESWIRE_H_ */