* lib/thread.rb (Queue#push, #pop, SizedQueue#push, #pop): remove

code that kicks waiting thread twice, which caused race and
  deadlock.  [ruby-core:25537]

* test/thread/test_queue.rb: added.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27356 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/thread/test_queue.rb

@@ -0,0 +1,38 @@
+require 'test/unit'
+require 'thread'
+
+class TestQueue < Test::Unit::TestCase
+  def test_queue
+    grind(5, 1000, 15, Queue)
+  end
+
+  def test_sized_queue
+    grind(5, 1000, 15, SizedQueue, 1000)
+  end
+
+  def grind(num_threads, num_objects, num_iterations, klass, *args)
+    from_workers = klass.new(*args)
+    to_workers = klass.new(*args)
+
+    workers = (1..num_threads).map {
+      Thread.new {
+        while object = to_workers.pop
+          from_workers.push object
+        end
+      }
+    }
+
+    Thread.new {
+      num_iterations.times {
+        num_objects.times { to_workers.push 99 }
+        num_objects.times { from_workers.pop }
+      }
+    }.join
+  
+    num_threads.times { to_workers.push nil }
+    workers.each { |t| t.join }
+
+    assert 0, from_workers.size
+    assert 0, to_workers.size
+  end
+end