Monitor#exit: check monitor ownership.

Monitor#exit should be called by only onwer Thread. However, there
is not check for it.

1 files changed, 23 insertions, 0 deletions

diff --git a/test/monitor/test_monitor.rb b/test/monitor/test_monitor.rb
index 49c34e067e..950db917e6 100644
--- a/test/monitor/test_monitor.rb
+++ b/test/monitor/test_monitor.rb
@@ -35,6 +35,29 @@ class TestMonitor < Test::Unit::TestCase
     assert_equal((1..10).to_a, ary)
   end
 
+  def test_exit
+    m = Monitor.new
+    m.enter
+    assert_equal true, m.mon_owned?
+    m.exit
+    assert_equal false, m.mon_owned?
+
+    assert_raise ThreadError do
+      m.exit
+    end
+
+    assert_equal false, m.mon_owned?
+
+    m.enter
+    Thread.new{
+      assert_raise(ThreadError) do
+        m.exit
+      end
+    }.join
+    assert_equal true, m.mon_owned?
+    m.exit
+  end
+
   def test_enter_second_after_killed_thread
     th = Thread.start {
       @monitor.enter