Add MonitorMinx#mon_locked? and #mon_owned? to check states of objects

Patched by Satoshi "Moris" Tagomori <tagomoris@gmail.com>.  [Fix GH-1699]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59971 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/monitor.rb

@@ -203,6 +203,20 @@ module MonitorMixin
     end
   end
 
+  #
+  # Returns true if this monitor is locked by any thread
+  #
+  def mon_locked?
+    @mon_mutex.locked?
+  end
+
+  #
+  # Returns true if this monitor is locked by current thread.
+  #
+  def mon_owned?
+    @mon_mutex.locked? && @mon_owner == Thread.current
+  end
+
   #
   # Enters exclusive section and executes the block.  Leaves the exclusive
   # section automatically when the block exits.  See example under

test/monitor/test_monitor.rb

@@ -146,6 +146,35 @@ class TestMonitor < Test::Unit::TestCase
     assert_join_threads([th, th2])
   end
 
+  def test_mon_locked_and_owned
+    queue1 = Queue.new
+    queue2 = Queue.new
+    th = Thread.start {
+      @monitor.enter
+      queue1.enq(nil)
+      queue2.deq
+      @monitor.exit
+      queue1.enq(nil)
+    }
+    queue1.deq
+    assert(@monitor.mon_locked?)
+    assert(!@monitor.mon_owned?)
+
+    queue2.enq(nil)
+    queue1.deq
+    assert(!@monitor.mon_locked?)
+
+    @monitor.enter
+    assert @monitor.mon_locked?
+    assert @monitor.mon_owned?
+    @monitor.exit
+
+    @monitor.synchronize do
+      assert @monitor.mon_locked?
+      assert @monitor.mon_owned?
+    end
+  end
+
   def test_cond
     cond = @monitor.new_cond