[PATCH wayland v4 02/11] client: Add WL_MAP_ENTRY_ZOMBIE flag

[Daniel Stone]

From: Derek Foreman <derekf at osg.samsung.com>

Add a new map entry flag to indicate that the object received is valid,
but a zombie. Previously this relied on a fixed object pointer, but
future patches in this series will have map entries returning either
NULL, or a different structure type entirely, for zombie objects.

wl_object_is_zombie() now solely uses the new flag to determine whether
or not the object is a zombie.

[daniels: Extracted from Derek's bespoke-zombie patch as an intermediate
          step.]

Signed-off-by: Derek Foreman <derekf at osg.samsung.com>
Reviewed-by: Daniel Stone <daniels at collabora.com>
Signed-off-by: Daniel Stone <daniels at collabora.com>
---
 src/connection.c      | 13 +++++++++++--
 src/wayland-client.c  | 14 ++++++++------
 src/wayland-private.h |  3 ++-
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/src/connection.c b/src/connection.c
index 2e234ea5..426be574 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -834,9 +834,18 @@ wl_connection_demarshal(struct wl_connection *connection,
 bool
 wl_object_is_zombie(struct wl_map *map, uint32_t id)
 {
-	struct wl_object *object = wl_map_lookup(map, id);
+	uint32_t flags;
 
-	return (object == WL_ZOMBIE_OBJECT);
+	/* Zombie objects only exist on the client side. */
+	if (map->side == WL_MAP_SERVER_SIDE)
+		return false;
+
+	/* Zombie objects can only have been created by the client. */
+	if (id >= WL_SERVER_ID_START)
+		return false;
+
+	flags = wl_map_lookup_flags(map, id);
+	return !!(flags & WL_MAP_ENTRY_ZOMBIE);
 }
 
 int
diff --git a/src/wayland-client.c b/src/wayland-client.c
index 126dd908..8fc56340 100644
--- a/src/wayland-client.c
+++ b/src/wayland-client.c
@@ -405,15 +405,17 @@ wl_proxy_create_for_id(struct wl_proxy *factory,
 static void
 proxy_destroy(struct wl_proxy *proxy)
 {
-	if (proxy->flags & WL_PROXY_FLAG_ID_DELETED)
+	if (proxy->flags & WL_PROXY_FLAG_ID_DELETED) {
 		wl_map_remove(&proxy->display->objects, proxy->object.id);
-	else if (proxy->object.id < WL_SERVER_ID_START)
-		wl_map_insert_at(&proxy->display->objects, 0,
-				 proxy->object.id, WL_ZOMBIE_OBJECT);
-	else
+	} else if (proxy->object.id < WL_SERVER_ID_START) {
+		wl_map_insert_at(&proxy->display->objects,
+				 WL_MAP_ENTRY_ZOMBIE,
+				 proxy->object.id,
+				 WL_ZOMBIE_OBJECT);
+	} else {
 		wl_map_insert_at(&proxy->display->objects, 0,
 				 proxy->object.id, NULL);
-
+	}
 
 	proxy->flags |= WL_PROXY_FLAG_DESTROYED;
 
diff --git a/src/wayland-private.h b/src/wayland-private.h
index c82b1f3e..b0d129f7 100644
--- a/src/wayland-private.h
+++ b/src/wayland-private.h
@@ -69,7 +69,8 @@ wl_interface_equal(const struct wl_interface *iface1,
  * flags.  If more flags are ever added, the implementation of wl_map will have
  * to change to allow for new flags */
 enum wl_map_entry_flags {
-	WL_MAP_ENTRY_LEGACY = (1 << 0)
+	WL_MAP_ENTRY_LEGACY = (1 << 0), /* Server side only */
+	WL_MAP_ENTRY_ZOMBIE = (1 << 0) /* Client side only */
 };
 
 struct wl_map {
-- 
2.14.3