ruby_1_8_monitor.diff

Index: lib/monitor.rb
===================================================================
--- lib/monitor.rb      (revision 23996)
+++ lib/monitor.rb      (working copy)
@@ -288,11 +288,15 @@
     @mon_owner = Thread.current
   end

+  # mon_release requires Thread.critical == true
   def mon_release
     @mon_owner = nil
-    t = @mon_waiting_queue.shift
-    t = @mon_entering_queue.shift unless t
-    t.wakeup if t
+    while t = @mon_waiting_queue.shift || @mon_entering_queue.shift
+      if t.alive?
+        t.wakeup
+        return
+      end
+    end
   end

   def mon_enter_for_cond(count)
Index: test/monitor/test_monitor.rb
===================================================================
--- test/monitor/test_monitor.rb        (revision 23996)
+++ test/monitor/test_monitor.rb        (working copy)
@@ -54,6 +54,31 @@
     assert_equal((1..10).to_a, ary)
   end

+  def test_killed_thread_in_synchronize
+    ary = []
+    queue = Queue.new
+    t1 = Thread.start {
+      queue.pop
+      @monitor.synchronize {
+        ary << :t1
+      }
+    }
+    t2 = Thread.start {
+      queue.pop
+      @monitor.synchronize {
+        ary << :t2
+      }
+    }
+    @monitor.synchronize do
+      queue.enq(nil)
+      queue.enq(nil)
+      t1.kill
+      t2.kill
+      ary << :main
+    end
+    assert_equal([:main], ary)
+  end
+
   def test_try_enter
     queue1 = Queue.new
     queue2 = Queue.new