shugo	2018-11-20 12:01:55 +0900 (Tue, 20 Nov 2018)

  New Revision: 65822

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=65822

  Log:
    lib/monitor.rb: prevent to initialize MonitorMixin twice
    
    Suggested by Benoit Daloze.  [ruby-core:88504] [Feature #15000]

  Added files:
    trunk/test/monitor/test_monitor_mixin.rb
  Modified files:
    trunk/lib/monitor.rb
Index: test/monitor/test_monitor_mixin.rb
===================================================================
--- test/monitor/test_monitor_mixin.rb	(nonexistent)
+++ test/monitor/test_monitor_mixin.rb	(revision 65822)
@@ -0,0 +1,37 @@ https://github.com/ruby/ruby/blob/trunk/test/monitor/test_monitor_mixin.rb#L1
+# frozen_string_literal: false
+require 'test/unit'
+require 'monitor'
+
+class TestMonitorMixin < Test::Unit::TestCase
+  def test_cond
+    a = "foo"
+    a.extend(MonitorMixin)
+    cond = a.new_cond
+    queue1 = Queue.new
+    th = Thread.start do
+      queue1.deq
+      a.synchronize do
+        a.replace("bar")
+        cond.signal
+      end
+    end
+    th2 = Thread.start do
+      a.synchronize do
+        queue1.enq(nil)
+        assert_equal("foo", a)
+        result1 = cond.wait
+        assert_equal(true, result1)
+        assert_equal("bar", a)
+      end
+    end
+    assert_join_threads([th, th2])
+  end
+
+  def test_initialize_twice
+    a = Object.new
+    a.extend(MonitorMixin)
+    assert_raise(ThreadError) do
+      a.send(:mon_initialize)
+    end
+  end
+end
Index: lib/monitor.rb
===================================================================
--- lib/monitor.rb	(revision 65821)
+++ lib/monitor.rb	(revision 65822)
@@ -251,9 +251,12 @@ module MonitorMixin https://github.com/ruby/ruby/blob/trunk/lib/monitor.rb#L251
   # Initializes the MonitorMixin after being included in a class or when an
   # object has been extended with the MonitorMixin
   def mon_initialize
+    if defined?(@mon_mutex)
+      raise ThreadError, "already initialized"
+    end
+    @mon_mutex = Thread::Mutex.new
     @mon_owner = nil
     @mon_count = 0
-    @mon_mutex = Thread::Mutex.new
   end
 
   def mon_check_owner

--
ML: ruby-changes@q...
Info: http://www.atdot.net/~ko1/quickml/