1 files changed, 48 insertions, 26 deletions

diff --git a/thread_sync.c b/thread_sync.c
index 5e511af0db..f3d1ccb120 100644
--- a/thread_sync.c
+++ b/thread_sync.c
@@ -321,6 +321,38 @@ rb_mutex_owned_p(VALUE self)
     return owned;
 }
 
+static void
+mutex_do_unlock(rb_mutex_t *mutex, rb_thread_t *th)
+{
+    struct sync_waiter *cur = 0, *next = 0;
+    rb_mutex_t **th_mutex = &th->keeping_mutexes;
+
+    VM_ASSERT(mutex->th == th);
+
+    mutex->th = 0;
+    list_for_each_safe(&mutex->waitq, cur, next, node) {
+        list_del_init(&cur->node);
+        switch (cur->th->status) {
+          case THREAD_RUNNABLE: /* from someone else calling Thread#run */
+          case THREAD_STOPPED_FOREVER: /* likely (rb_mutex_lock) */
+            rb_threadptr_interrupt(cur->th);
+            goto found;
+          case THREAD_STOPPED: /* probably impossible */
+            rb_bug("unexpected THREAD_STOPPED");
+          case THREAD_KILLED:
+            /* not sure about this, possible in exit GC? */
+            rb_bug("unexpected THREAD_KILLED");
+            continue;
+        }
+    }
+  found:
+    while (*th_mutex != mutex) {
+        th_mutex = &(*th_mutex)->next_mutex;
+    }
+    *th_mutex = mutex->next_mutex;
+    mutex->next_mutex = NULL;
+}
+
 static const char *
 rb_mutex_unlock_th(rb_mutex_t *mutex, rb_thread_t *th)
 {
@@ -333,31 +365,7 @@ rb_mutex_unlock_th(rb_mutex_t *mutex, rb_thread_t *th)
 	err = "Attempt to unlock a mutex which is locked by another thread";
     }
     else {
-	struct sync_waiter *cur = 0, *next = 0;
-	rb_mutex_t **th_mutex = &th->keeping_mutexes;
-
-	mutex->th = 0;
-	list_for_each_safe(&mutex->waitq, cur, next, node) {
-	    list_del_init(&cur->node);
-	    switch (cur->th->status) {
-	      case THREAD_RUNNABLE: /* from someone else calling Thread#run */
-	      case THREAD_STOPPED_FOREVER: /* likely (rb_mutex_lock) */
-		rb_threadptr_interrupt(cur->th);
-		goto found;
-	      case THREAD_STOPPED: /* probably impossible */
-		rb_bug("unexpected THREAD_STOPPED");
-	      case THREAD_KILLED:
-                /* not sure about this, possible in exit GC? */
-		rb_bug("unexpected THREAD_KILLED");
-		continue;
-	    }
-	}
-      found:
-	while (*th_mutex != mutex) {
-	    th_mutex = &(*th_mutex)->next_mutex;
-	}
-	*th_mutex = mutex->next_mutex;
-	mutex->next_mutex = NULL;
+        mutex_do_unlock(mutex, th);
     }
 
     return err;
@@ -497,6 +505,20 @@ mutex_sleep(int argc, VALUE *argv, VALUE self)
     return rb_mutex_sleep(self, timeout);
 }
 
+static VALUE
+mutex_unlock_if_owned(VALUE self)
+{
+    rb_thread_t *th = GET_THREAD();
+    rb_mutex_t *mutex;
+    GetMutexPtr(self, mutex);
+
+    /* we may not own the mutex if an exception occured */
+    if (mutex->th == th) {
+        mutex_do_unlock(mutex, th);
+    }
+    return Qfalse;
+}
+
 /*
  * call-seq:
  *    mutex.synchronize { ... }    -> result of the block
@@ -509,7 +531,7 @@ VALUE
 rb_mutex_synchronize(VALUE mutex, VALUE (*func)(VALUE arg), VALUE arg)
 {
     rb_mutex_lock(mutex);
-    return rb_ensure(func, arg, rb_mutex_unlock, mutex);
+    return rb_ensure(func, arg, mutex_unlock_if_owned, mutex);
 }
 
 /*