implement some more apis

include/re_thread.h

@@ -28,9 +28,9 @@ typedef int thread_once_flag;
 /**
  * Creates a new thread
  *
- * @param thr  Pointer to new thread
- * @param func Function to execute
- * @param arg  Argument to pass to the function
+ * @param thr   Pointer to new thread
+ * @param func  Function to execute
+ * @param arg   Argument to pass to the function
  *
  * @return 0 if success, otherwise errorcode
  */
@@ -44,7 +44,7 @@ int thread_create(thread *thr, thread_h func, void *arg);
 int thread_equal(thread lhs, thread rhs);
 
 /**
- * @return the identifier of the calling thread.
+ * Return the identifier of the calling thread.
  */
 thread thread_current(void);
 
@@ -59,14 +59,26 @@ int thread_detach(thread thr);
  * Blocks the current thread until the thread identified by thr finishes
  * execution
  *
- * @param thr Thread
- * @param res Result code location
+ * @param thr  Thread
+ * @param res  Result code location
  *
  * @return 0 if success, otherwise errorcode
  */
 int thread_join(thread thr, int *res);
 
-int thread_once(thread_once_flag *flag, void (*func)(void));
+/**
+ * Calls a function exactly once
+ *
+ * @param flag  Pointer to object initialized by THREAD_ONCE_FLAG_INIT
+ * @param func  The function to execute only once
+ */
+void thread_once(thread_once_flag *flag, void (*func)(void));
+
+/**
+ * Terminates the calling thread
+ *
+ * @param res
+ */
 void thread_exit(int res);
 
 int thread_cond_init(thread_cond *cond);

src/thread/posix.c

@@ -22,9 +22,7 @@ static void *thread_handler(void *p)
 
 	mem_deref(p);
 
-	th.func(th.arg);
-
-	return NULL;
+	return (void *)(intptr_t)th.func(th.arg);
 }
 
 
@@ -81,3 +79,15 @@ int thread_join(thread thr, int *res)
 
 	return err;
 }
+
+
+void thread_once(thread_once_flag *flag, void (*func)(void))
+{
+	pthread_once(flag, func);
+}
+
+
+void thread_exit(int res)
+{
+	pthread_exit((void *)(intptr_t)res);
+}