Add latest JRuby version with JDK-11

Author: prashantvithani

.travis.yml

@@ -9,8 +9,11 @@ matrix:
   include:
     - name: MRI 2.5.1 Latest
       rvm: 2.5.1
-    - name: JRuby 9.2.0.0 Latest
-      rvm: jruby-9.2.0.0
+    - name: JRuby 9.2.4.1 Latest on Java 11
+      rvm: jruby-9.2.4.1
+      jdk: oraclejdk11
+    - name: JRuby 9.2.4.1 Latest on Java 8
+      rvm: jruby-9.2.4.1
       jdk: oraclejdk8
     - name: TruffleRuby Latest
       rvm: system

Rakefile

@@ -23,18 +23,29 @@ JRUBY_JAR_PATH = '/usr/local/opt/rbenv/versions/jruby-9.1.17.0/lib/jruby.jar'
 class ConcurrentRubyJavaExtensionTask < Rake::JavaExtensionTask
   def java_classpath_arg(*args)
     jruby_cpath = nil
+
     if RUBY_PLATFORM =~ /java/
       begin
         cpath       = Java::java.lang.System.getProperty('java.class.path').split(File::PATH_SEPARATOR)
         cpath       += Java::java.lang.System.getProperty('sun.boot.class.path').split(File::PATH_SEPARATOR)
         jruby_cpath = cpath.compact.join(File::PATH_SEPARATOR)
       rescue => e
       end
+
+      unless jruby_cpath
+        libdir = RbConfig::CONFIG['libdir']
+        if libdir.start_with? "classpath:"
+          raise 'Cannot build with jruby-complete'
+        end
+        jruby_cpath = File.join(libdir, "jruby.jar")
+      end
     end
+
     unless jruby_cpath
       jruby_cpath = JRUBY_JAR_PATH
       raise "#{jruby_cpath} does not exist" unless File.exist? jruby_cpath
     end
+
     jruby_cpath += File::PATH_SEPARATOR + args.join(File::PATH_SEPARATOR) unless args.empty?
     jruby_cpath ? "-cp \"#{jruby_cpath}\"" : ""
   end

spec/concurrent/synchronization_spec.rb

@@ -181,10 +181,20 @@ def ns_initialize
 
       specify 'final field always visible' do
         store = BClass.new 'asd'
-        t1    = in_thread { 1000000000.times { |i| store = BClass.new i.to_s } }
-        t2    = in_thread { 10.times { expect(store.final).not_to be_nil; Thread.pass } }
-        t2.join
-        t1.kill
+        done  = CountDownLatch.new
+        in_thread do
+          1000000000.times do |i|
+            store = BClass.new i.to_s
+            break if done.count == 0
+          end
+        end
+        in_thread do
+          10.times do
+            expect(store.final).not_to be_nil
+            Thread.pass
+          end
+          done.count_down
+        end
       end
 
       let(:store) { BClass.new }