Merge pull request #434 from ruby-concurrency/better-java-ext-loading

Improved java extension loading.

Author: jdantonio

lib/concurrent/atomic/atomic_boolean.rb

@@ -48,7 +48,7 @@ module Concurrent
   #   Explicitly sets the value to false.
   #
   #   @return [Boolean] true is value has changed, otherwise false
-  
+
   ###################################################################
 
   # @!macro [new] atomic_boolean_public_api
@@ -79,7 +79,7 @@ module Concurrent
   # @!visibility private
   # @!macro internal_implementation_note
   AtomicBooleanImplementation = case
-                                when Concurrent.on_jruby?
+                                when defined?(JavaAtomicBoolean)
                                   JavaAtomicBoolean
                                 when defined?(CAtomicBoolean)
                                   CAtomicBoolean

lib/concurrent/atomic/atomic_fixnum.rb

@@ -96,7 +96,7 @@ module Concurrent
   # @!visibility private
   # @!macro internal_implementation_note
   AtomicFixnumImplementation = case
-                               when Concurrent.on_jruby?
+                               when defined?(JavaAtomicFixnum)
                                  JavaAtomicFixnum
                                when defined?(CAtomicFixnum)
                                  CAtomicFixnum

lib/concurrent/atomic/semaphore.rb

@@ -91,7 +91,7 @@ module Concurrent
   # @!visibility private
   # @!macro internal_implementation_note
   SemaphoreImplementation = case
-                            when Concurrent.on_jruby?
+                            when defined?(JavaSemaphore)
                               JavaSemaphore
                             else
                               MutexSemaphore

lib/concurrent/map.rb

@@ -1,30 +1,31 @@
 require 'thread'
 require 'concurrent/constants'
+require 'concurrent/utility/native_extension_loader'
 
 module Concurrent
   # @!visibility private
   module Collection
 
     # @!visibility private
-    MapImplementation = if defined?(RUBY_ENGINE)
-                   case RUBY_ENGINE
-                   when 'jruby'
-                     # noinspection RubyResolve
-                     JRubyMapBackend
-                   when 'ruby'
-                     require 'concurrent/collection/map/mri_map_backend'
-                     MriMapBackend
-                   when 'rbx'
-                     require 'concurrent/collection/map/atomic_reference_map_backend'
-                     AtomicReferenceMapBackend
-                   else
-                     warn 'Concurrent::Map: unsupported Ruby engine, using a fully synchronized Concurrent::Map implementation' if $VERBOSE
-                     require 'concurrent/collection/map/synchronized_map_backend'
-                     SynchronizedMapBackend
-                   end
-                 else
-                   MriMapBackend
-                 end
+    MapImplementation = if Concurrent.java_extensions_loaded?
+                          # noinspection RubyResolve
+                          JRubyMapBackend
+                        elsif defined?(RUBY_ENGINE)
+                          case RUBY_ENGINE
+                          when 'ruby'
+                            require 'concurrent/collection/map/mri_map_backend'
+                            MriMapBackend
+                          when 'rbx'
+                            require 'concurrent/collection/map/atomic_reference_map_backend'
+                            AtomicReferenceMapBackend
+                          else
+                            warn 'Concurrent::Map: unsupported Ruby engine, using a fully synchronized Concurrent::Map implementation' if $VERBOSE
+                            require 'concurrent/collection/map/synchronized_map_backend'
+                            SynchronizedMapBackend
+                          end
+                        else
+                          MriMapBackend
+                        end
   end
 
   # `Concurrent::Map` is a hash-like object and should have much better performance

lib/concurrent/synchronization/jruby_lockable_object.rb

@@ -1,7 +1,7 @@
 module Concurrent
   module Synchronization
 
-    if Concurrent.on_jruby?
+    if Concurrent.on_jruby? && Concurrent.java_extensions_loaded?
 
       # @!visibility private
       # @!macro internal_implementation_note

lib/concurrent/synchronization/jruby_object.rb

@@ -1,7 +1,7 @@
 module Concurrent
   module Synchronization
 
-    if Concurrent.on_jruby?
+    if Concurrent.on_jruby? && Concurrent.java_extensions_loaded?
 
       # @!visibility private
       # @!macro internal_implementation_note

lib/concurrent/synchronization/lockable_object.rb

@@ -8,7 +8,7 @@ module Synchronization
                                      MriMonitorLockableObject
                                    when Concurrent.on_cruby? && Concurrent.ruby_version(:>, 1, 9, 3)
                                      MriMutexLockableObject
-                                   when Concurrent.on_jruby?
+                                   when defined? JRubyLockableObject
                                      JRubyLockableObject
                                    when Concurrent.on_rbx?
                                      RbxLockableObject

lib/concurrent/synchronization/object.rb

@@ -6,7 +6,7 @@ module Synchronization
     ObjectImplementation = case
                            when Concurrent.on_cruby?
                              MriObject
-                           when Concurrent.on_jruby?
+                           when defined? JRubyObject
                              JRubyObject
                            when Concurrent.on_rbx?
                              RbxObject

lib/concurrent/utility/native_extension_loader.rb

@@ -7,42 +7,57 @@ module Utility
     # @!visibility private
     module NativeExtensionLoader
 
-      @c_ext_loaded    ||= false
-      @java_ext_loaded ||= false
-
-      # @!visibility private
       def allow_c_extensions?
         Concurrent.on_cruby?
       end
 
-      if Concurrent.on_cruby? && !@c_ext_loaded
-        tries = [
-          lambda do
-            require 'concurrent/extension'
-            @c_ext_loaded = true
-          end,
-          lambda do
-            # may be a Windows cross-compiled native gem
-            require "concurrent/#{RUBY_VERSION[0..2]}/extension"
-            @c_ext_loaded = true
-          end]
-
-        tries.each do |try|
-          begin
-            try.call
-            break
-          rescue LoadError
-            next
+      def c_extensions_loaded?
+        @c_extensions_loaded ||= false
+      end
+
+      def java_extensions_loaded?
+        @java_extensions_loaded ||= false
+      end
+
+      def set_c_extensions_loaded
+        @c_extensions_loaded = true
+      end
+
+      def set_java_extensions_loaded
+        @java_extensions_loaded = true
+      end
+
+      def load_native_extensions
+        if Concurrent.on_cruby? && !c_extensions_loaded?
+          tries = [
+            lambda do
+              require 'concurrent/extension'
+              set_c_extensions_loaded
+            end,
+            lambda do
+              # may be a Windows cross-compiled native gem
+              require "concurrent/#{RUBY_VERSION[0..2]}/extension"
+              set_c_extensions_loaded
+            end]
+
+          tries.each do |try|
+            begin
+              try.call
+              break
+            rescue LoadError
+              next
+            end
           end
         end
-      end
 
-      if Concurrent.on_jruby? && !@java_ext_loaded
-        begin
-          require 'concurrent_ruby_ext'
-          @java_ext_loaded = true
-        rescue LoadError
-          # move on with pure-Ruby implementations
+        if Concurrent.on_jruby? && !java_extensions_loaded?
+          begin
+            require 'concurrent_ruby_ext'
+            set_java_extensions_loaded
+          rescue LoadError
+            # move on with pure-Ruby implementations
+            warn 'On JRuby but Java extensions failed to load.'
+          end
         end
       end
     end
@@ -51,3 +66,5 @@ def allow_c_extensions?
   # @!visibility private
   extend Utility::NativeExtensionLoader
 end
+
+Concurrent.load_native_extensions