lib/journeta/asynchronous.rb in journeta-0.0.2 vs lib/journeta/asynchronous.rb in journeta-0.0.3

@@ -1,34 +1,65 @@
-require 'journeta/logger'
+# Copyright 2007, OpenRain, LLC. All rights reserved.
 
-module Journeta
 
-   class Asynchronous
-      
-      include Logger
-      
-      attr_accessor :thread, :engine
+require 'journeta/logger'
 
-      def initialize(engine)
-         @engine = engine
+module Journeta
+  
+  class Asynchronous
+    
+    include Logger
+    
+    attr_accessor :thread, :engine
+    
+    
+    
+    def initialize(engine)
+      @engine = engine
+      @thread_lock = Mutex.new
+      @thread = nil
+    end
+    
+    
+    
+    # Start the +Thread+ for this instance, iff not already running.
+    def start
+      @thread_lock.synchronize do
+        if @thread
+          # Do not restart it.
+        else
+          putsd "Creating asynchronous thread for I/O: #{self.class.to_s}."
+          @thread = Thread.new {
+            go
+          }
+        end
       end
-      
-      def start
-         putsd "Creating asynchronous thread for I/O: #{self.class.to_s}."
-         @thread = Thread.new {
-            go # @engine
-         }
+    end
+    
+    # This method is intentionally not present because it would be of no real value. By the time a boolean is returned, the instance could be in a totally different state.
+    #    def started  
+    #      stopped = true
+    #      @thread_lock.synchronize do
+    #        stopped = @thread.nil?
+    #      end
+    #      return stopped
+    #    end
+    
+    # Stop the +Thread+ associated with this instance, iff not already stopped.
+    def stop
+      @thread_lock.synchronize do
+        if @thread
+          Thread.kill(@thread)
+          @thread.join
+          @thread = nil
+        end
       end
-      	      
-      def stop
-         Thread.kill(@thread)
-         @thread.join
-         @thread = nil
-   	end
-   	
-   	def go #(engine)
-   	   raise NotImplementedException
-	   end
-	   
-	end
-	
+    end
+    
+    # Abstract thread logic method which must be implemented by the sub-class.
+    def go
+      raise NotImplementedException
+    end
+    
+  end
+  
 end