1 files changed, 6 insertions, 1 deletions
diff --git a/thread_sync.c b/thread_sync.c
index 2e20812f4d..3689dee789 100644
--- a/thread_sync.c
+++ b/thread_sync.c
@@ -190,6 +190,8 @@ mutex_locked(rb_thread_t *th, VALUE self)
 	mutex->next_mutex = th->keeping_mutexes;
     }
     th->keeping_mutexes = mutex;
+
+    th->blocking += 1;
 }
 
 /*
@@ -365,6 +367,8 @@ rb_mutex_unlock_th(rb_mutex_t *mutex, rb_thread_t *th)
 	struct sync_waiter *cur = 0, *next;
 	rb_mutex_t **th_mutex = &th->keeping_mutexes;
 
+        th->blocking -= 1;
+
 	mutex->th = 0;
 	list_for_each_safe(&mutex->waitq, cur, next, node) {
 	    list_del_init(&cur->node);
@@ -404,8 +408,9 @@ rb_mutex_unlock(VALUE self)
 {
     const char *err;
     rb_mutex_t *mutex = mutex_ptr(self);
+    rb_thread_t *th = GET_THREAD();
 
-    err = rb_mutex_unlock_th(mutex, GET_THREAD());
+    err = rb_mutex_unlock_th(mutex, th);
     if (err) rb_raise(rb_eThreadError, "%s", err);
 
     return self;