Revert "Rollback using Java Exchanger and CountDownLatch implementations"

This reverts commit 1e51d2c.

Author: pitr-ch

lib/concurrent/atomic/count_down_latch.rb

@@ -55,7 +55,7 @@ module Concurrent
   # @!macro internal_implementation_note
   CountDownLatchImplementation = case
                                  when Concurrent.on_jruby?
-                                   MutexCountDownLatch
+                                   JavaCountDownLatch
                                  else
                                    MutexCountDownLatch
                                  end

lib/concurrent/exchanger.rb

@@ -329,7 +329,7 @@ def do_exchange(value, timeout)
   # @!macro internal_implementation_note
   ExchangerImplementation = case
                             when Concurrent.on_jruby?
-                              RubyExchanger
+                              JavaExchanger
                             else
                               RubyExchanger
                             end

spec/concurrent/atomic/count_down_latch_spec.rb

@@ -153,21 +153,21 @@ def subject.simulate_spurious_wake_up
     end
   end
 
-  # if Concurrent.on_jruby?
-  #   RSpec.describe JavaCountDownLatch do
-  #     it_should_behave_like :count_down_latch
-  #   end
-  # end
+  if Concurrent.on_jruby?
+    RSpec.describe JavaCountDownLatch do
+      it_should_behave_like :count_down_latch
+    end
+  end
 
   RSpec.describe CountDownLatch do
-    # if Concurrent.on_jruby?
-    #   it 'inherits from JavaCountDownLatch' do
-    #     expect(CountDownLatch.ancestors).to include(JavaCountDownLatch)
-    #   end
-    # else
-    it 'inherits from MutexCountDownLatch' do
-      expect(CountDownLatch.ancestors).to include(MutexCountDownLatch)
+    if Concurrent.on_jruby?
+      it 'inherits from JavaCountDownLatch' do
+        expect(CountDownLatch.ancestors).to include(JavaCountDownLatch)
+      end
+    else
+      it 'inherits from MutexCountDownLatch' do
+        expect(CountDownLatch.ancestors).to include(MutexCountDownLatch)
+      end
     end
-    # end
   end
 end

spec/concurrent/exchanger_spec.rb

@@ -237,26 +237,26 @@ module Concurrent
     end
   end
 
-  # if defined? JavaExchanger
-  #
-  #   RSpec.describe JavaExchanger do
-  #     it_behaves_like :exchanger
-  #   end
-  # end
+  if defined? JavaExchanger
+
+    RSpec.describe JavaExchanger do
+      it_behaves_like :exchanger
+    end
+  end
 
   RSpec.describe Exchanger do
 
     context 'class hierarchy' do
 
-      # if Concurrent.on_jruby?
-      #   it 'inherits from JavaExchanger' do
-      #     expect(Exchanger.ancestors).to include(JavaExchanger)
-      #   end
-      # else
-      it 'inherits from RubyExchanger' do
-        expect(Exchanger.ancestors).to include(RubyExchanger)
+      if Concurrent.on_jruby?
+        it 'inherits from JavaExchanger' do
+          expect(Exchanger.ancestors).to include(JavaExchanger)
+        end
+      else
+        it 'inherits from RubyExchanger' do
+          expect(Exchanger.ancestors).to include(RubyExchanger)
+        end
       end
-      # end
     end
   end
 end