* thread_pthread.c (ubf_select): add to small comments why we

need to call rb_thread_wakeup_timer_thread().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39684 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed Mar  6 22:56:14 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* thread_pthread.c (ubf_select): add to small comments why we
+	  need to call rb_thread_wakeup_timer_thread().
+
 Wed Mar  6 21:42:24 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* thread_pthread.c (rb_thread_create_timer_thread): factor out

thread_pthread.c

@@ -1098,8 +1098,16 @@ ubf_select(void *ptr)
 {
     rb_thread_t *th = (rb_thread_t *)ptr;
     add_signal_thread_list(th);
+
+    /*
+     * ubf_select_each() doesn't guarantee to wake up the target thread.
+     * Therefore, we need to activate timer thread when called from
+     * Thread#kill etc.
+     * In the other hands, we shouldn't call rb_thread_wakeup_timer_thread()
+     * if running on timer thread because it may make endless wakeups.
+     */
     if (pthread_self() != timer_thread_id)
-	rb_thread_wakeup_timer_thread(); /* activate timer thread */
+	rb_thread_wakeup_timer_thread();
     ubf_select_each(th);
 }