Fix up a variety of Ruby warnings

lib/concurrent/async.rb

@@ -81,13 +81,13 @@ def method_missing(method, *args, &block)
         super unless @delegate.respond_to?(method)
         Async::validate_argc(@delegate, method, *args)
 
-        self.define_singleton_method(method) do |*args|
-          Async::validate_argc(@delegate, method, *args)
+        self.define_singleton_method(method) do |*args2|
+          Async::validate_argc(@delegate, method, *args2)
           ivar = Concurrent::IVar.new
           value, reason = nil, nil
           @serializer.post(@executor.value) do
             begin
-              value = @delegate.send(method, *args, &block)
+              value = @delegate.send(method, *args2, &block)
             rescue => reason
               # caught
             ensure

lib/concurrent/atomic/atomic_fixnum.rb

@@ -25,8 +25,8 @@ module Concurrent
   class MutexAtomicFixnum
 
     # http://stackoverflow.com/questions/535721/ruby-max-integer
-    MIN_VALUE = -(2**(0.size * 8 -2))
-    MAX_VALUE = (2**(0.size * 8 -2) -1)
+    MIN_VALUE = -(2**(0.size * 8 - 2))
+    MAX_VALUE = (2**(0.size * 8 - 2) - 1)
 
     # @!macro [attach] atomic_fixnum_method_initialize
     #

lib/concurrent/executor/indirect_immediate_executor.rb

@@ -28,7 +28,7 @@ def post(*args, &task)
       return false unless running?
 
       event = Concurrent::Event.new
-      internal_executor.post do
+      @internal_executor.post do
         begin
           task.call(*args)
         ensure
@@ -39,8 +39,5 @@ def post(*args, &task)
 
       true
     end
-
-    private
-    attr_reader :internal_executor
   end
 end

lib/concurrent/executor/ruby_thread_pool_worker.rb

@@ -13,6 +13,7 @@ def initialize(queue, parent)
       @parent = parent
       @mutex = Mutex.new
       @last_activity = Time.now.to_f
+      @thread = nil
     end
 
     # @!visibility private

lib/concurrent/executor/serialized_execution.rb

@@ -12,7 +12,7 @@ class SerializedExecution
 
     Job = Struct.new(:executor, :args, :block) do
       def call
-        block.call *args
+        block.call(*args)
       end
     end
 

lib/concurrent/lazy_register.rb

@@ -49,7 +49,7 @@ def register(key, &block)
     # @return self
     # @param [Object] key
     def unregister(key)
-      @data.update { |h| h.dup.tap { |h| h.delete(key) } }
+      @data.update { |h| h.dup.tap { |j| j.delete(key) } }
       self
     end
 

lib/concurrent/observable.rb

@@ -46,7 +46,7 @@ def add_observer(*args, &block)
     # as #add_observer but it can be used for chaining
     # @return [Observable] self
     def with_observer(*args, &block)
-      add_observer *args, &block
+      add_observer(*args, &block)
       self
     end
 

lib/concurrent/promise.rb

@@ -100,7 +100,7 @@ def then(rescuer = nil, &block)
     # @return [Promise]
     def on_success(&block)
       raise ArgumentError.new('no block given') unless block_given?
-      self.then &block
+      self.then(&block)
     end
 
     # @return [Promise]

lib/concurrent/scheduled_task.rb

@@ -26,7 +26,7 @@ def initialize(intended_time, opts = {}, &block)
     def execute
       if compare_and_set_state(:pending, :unscheduled)
         @schedule_time = TimerSet.calculate_schedule_time(@intended_time)
-        Concurrent::timer(@schedule_time.to_f - Time.now.to_f) { @executor.post &method(:process_task) }
+        Concurrent::timer(@schedule_time.to_f - Time.now.to_f) { @executor.post(&method(:process_task)) }
         self
       end
     end

lib/concurrent/timer_task.rb

@@ -317,7 +317,7 @@ def schedule_next_task(interval = execution_interval)
     def execute_task(completion)
       return unless @running.true?
       Concurrent::timer(execution_interval, completion, &method(:timeout_task))
-      success, value, reason = @executor.execute(self)
+      _success, value, reason = @executor.execute(self)
       if completion.try?
         self.value = value
         schedule_next_task