Switch protocol to using serial numbers for ordering events and requests

The wayland protocol, as X, uses timestamps to match up certain
requests with input events.  The problem is that sometimes we need to
send out an event that doesn't have a corresponding timestamped input
event.  For example, the pointer focus surface goes away and new
surface needs to receive a pointer enter event.  These events are
normally timestamped with the evdev event timestamp, but in this case,
we don't have a evdev timestamp.  So we have to go to gettimeofday (or
clock_gettime()) and then we don't know if it's coming from the same
time source etc.

However for all these cases we don't need a real time timestamp, we
just need a serial number that encodes the order of events inside the
server.  So we introduce a serial number mechanism that we can use to
order events.  We still need real-time timestamps for actual input
device events (motion, buttons, keys, touch), to be able to reason
about double-click speed and movement speed so events that correspond to user input carry both a serial number and a timestamp.

The serial number also give us a mechanism to key together events that
are "logically the same" such as a unicode event and a keycode event,
or a motion event and a relative event from a raw device.

1 files changed, 26 insertions, 21 deletions

diff --git a/src/data-device.c b/src/data-device.c
index 03997f1..1d22a84 100644
--- a/src/data-device.c
+++ b/src/data-device.c
@@ -29,7 +29,7 @@
 
 static void
 data_offer_accept(struct wl_client *client, struct wl_resource *resource,
-		  uint32_t time, const char *mime_type)
+		  uint32_t serial, const char *mime_type)
 {
 	struct wl_data_offer *offer = resource->data;
 
@@ -58,7 +58,7 @@ data_offer_receive(struct wl_client *client, struct wl_resource *resource,
 static void
 data_offer_destroy(struct wl_client *client, struct wl_resource *resource)
 {
-	wl_resource_destroy(resource, 0);
+	wl_resource_destroy(resource);
 }
 
 static void
@@ -78,7 +78,7 @@ static const struct wl_data_offer_interface data_offer_interface = {
 
 static void
 destroy_offer_data_source(struct wl_listener *listener,
-			  struct wl_resource *resource, uint32_t time)
+			  struct wl_resource *resource)
 {
 	struct wl_data_offer *offer;
 
@@ -146,7 +146,7 @@ data_source_offer(struct wl_client *client,
 static void
 data_source_destroy(struct wl_client *client, struct wl_resource *resource)
 {
-	wl_resource_destroy(resource, 0);
+	wl_resource_destroy(resource);
 }
 
 static struct wl_data_source_interface data_source_interface = {
@@ -169,7 +169,7 @@ find_resource(struct wl_list *list, struct wl_client *client)
 
 static void
 destroy_drag_focus(struct wl_listener *listener,
-		   struct wl_resource *resource, uint32_t time)
+		   struct wl_resource *resource)
 {
 	struct wl_input_device *device =
 		container_of(listener, struct wl_input_device,
@@ -179,12 +179,14 @@ destroy_drag_focus(struct wl_listener *listener,
 }
 
 static void
-drag_grab_focus(struct wl_pointer_grab *grab, uint32_t time,
+drag_grab_focus(struct wl_pointer_grab *grab,
 		struct wl_surface *surface, int32_t x, int32_t y)
 {
 	struct wl_input_device *device =
 		container_of(grab, struct wl_input_device, drag_grab);
 	struct wl_resource *resource, *offer;
+	struct wl_display *display;
+	uint32_t serial;
 
 	if (device->drag_focus_resource) {
 		wl_data_device_send_leave(device->drag_focus_resource);
@@ -197,10 +199,13 @@ drag_grab_focus(struct wl_pointer_grab *grab, uint32_t time,
 		resource = find_resource(&device->drag_resource_list, 
 					 surface->resource.client);
 	if (surface && resource) {
+		display = wl_client_get_display(resource->client);
+		serial = wl_display_next_serial(display);
+
 		offer = wl_data_source_send_offer(device->drag_data_source,
 						  resource);
 
-		wl_data_device_send_enter(resource, time, &surface->resource,
+		wl_data_device_send_enter(resource, serial, &surface->resource,
 					  x, y, offer);
 
 		device->drag_focus = surface;
@@ -225,7 +230,7 @@ drag_grab_motion(struct wl_pointer_grab *grab,
 }
 
 static void
-data_device_end_drag_grab(struct wl_input_device *device, uint32_t time)
+data_device_end_drag_grab(struct wl_input_device *device)
 {
 	struct wl_resource *surface_resource;
 	struct wl_surface_interface *implementation;
@@ -240,7 +245,7 @@ data_device_end_drag_grab(struct wl_input_device *device, uint32_t time)
 		wl_list_remove(&device->drag_icon_listener.link);
 	}
 
-	wl_input_device_end_pointer_grab(device, time);
+	wl_input_device_end_pointer_grab(device);
 
 	device->drag_data_source = NULL;
 	device->drag_surface = NULL;
@@ -258,7 +263,7 @@ drag_grab_button(struct wl_pointer_grab *grab,
 		wl_data_device_send_drop(device->drag_focus_resource);
 
 	if (device->button_count == 0 && state == 0) {
-		data_device_end_drag_grab(device, time);
+		data_device_end_drag_grab(device);
 		wl_list_remove(&device->drag_data_source_listener.link);
 	}
 }
@@ -271,19 +276,19 @@ static const struct wl_pointer_grab_interface drag_grab_interface = {
 
 static void
 destroy_data_device_source(struct wl_listener *listener,
-			   struct wl_resource *resource, uint32_t time)
+			   struct wl_resource *resource)
 {
 	struct wl_input_device *device;
 
 	device = container_of(listener, struct wl_input_device,
 			      drag_data_source_listener);
 
-	data_device_end_drag_grab(device, time);
+	data_device_end_drag_grab(device);
 }
 
 static void
 destroy_data_device_icon(struct wl_listener *listener,
-			 struct wl_resource *resource, uint32_t time)
+			 struct wl_resource *resource)
 {
 	struct wl_input_device *device;
 
@@ -297,7 +302,7 @@ static void
 data_device_start_drag(struct wl_client *client, struct wl_resource *resource,
 		       struct wl_resource *source_resource,
 		       struct wl_resource *origin_resource,
-		       struct wl_resource *icon_resource, uint32_t time)
+		       struct wl_resource *icon_resource, uint32_t serial)
 {
 	struct wl_input_device *device = resource->data;
 	struct wl_listener *listener, *tmp;
@@ -322,15 +327,15 @@ data_device_start_drag(struct wl_client *client, struct wl_resource *resource,
 
 		wl_list_for_each_safe(listener, tmp,
 				      &device->drag_icon_listener_list, link)
-			listener->func(listener, icon_resource, time);
+			listener->func(listener, icon_resource);
 	}
 
-	wl_input_device_start_pointer_grab(device, &device->drag_grab, time);
+	wl_input_device_start_pointer_grab(device, &device->drag_grab);
 }
 
 static void
 destroy_selection_data_source(struct wl_listener *listener,
-			      struct wl_resource *resource, uint32_t time)
+			      struct wl_resource *resource)
 {
 	struct wl_input_device *device =
 		container_of(listener, struct wl_input_device,
@@ -349,7 +354,7 @@ destroy_selection_data_source(struct wl_listener *listener,
 
 WL_EXPORT void
 wl_input_device_set_selection(struct wl_input_device *device,
-			      struct wl_data_source *source, uint32_t time)
+			      struct wl_data_source *source)
 {
 	struct wl_resource *data_device, *focus, *offer;
 	struct wl_selection_listener *listener, *next;
@@ -386,13 +391,13 @@ wl_input_device_set_selection(struct wl_input_device *device,
 static void
 data_device_set_selection(struct wl_client *client,
 			  struct wl_resource *resource,
-			  struct wl_resource *source_resource, uint32_t time)
+			  struct wl_resource *source_resource, uint32_t serial)
 {
 	if (!source_resource)
 		return;
 
-	wl_input_device_set_selection(resource->data,
-				      source_resource->data, time);
+	/* FIXME: Store serial and check against incoming serial here. */
+	wl_input_device_set_selection(resource->data, source_resource->data);
 }
 
 static const struct wl_data_device_interface data_device_interface = {