server: Add support for queuing a user APC upon async I/O completion.
diff --git a/server/protocol.def b/server/protocol.def
index 5105fd6..ef20235 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -178,6 +178,8 @@
     void           *callback;      /* client-side callback to call upon end of async */
     void           *iosb;          /* I/O status block in client addr space */
     void           *arg;           /* opaque user data to pass to callback */
+    void           *apc;           /* user apc to call */
+    void           *apc_arg;       /* argument for user apc */
     obj_handle_t    event;         /* event to signal when done */
 } async_data_t;