Add thread structure

src/utility/mod.rs

@@ -1 +1,2 @@
-pub mod list;
+pub mod list;
+pub mod system;

src/utility/system.rs

@@ -0,0 +1,9 @@
+
+pub enum ObjectType {
+    SEMAPHORE_TYPE,
+    LOCK_TYPE,
+    CONDITION_TYPE,
+    FILE_TYPE,
+    THREAD_TYPE,
+    INVALID_TYPE
+}