added Worker#pid method

Author: morgoth

lib/resque/worker.rb

@@ -453,7 +453,7 @@ def inspect
     # The string representation is the same as the id for this worker
     # instance. Can be used with `Worker.find`.
     def to_s
-      @to_s ||= "#{hostname}:#{Process.pid}:#{@queues.join(',')}"
+      @to_s ||= "#{hostname}:#{pid}:#{@queues.join(',')}"
     end
     alias_method :id, :to_s
 
@@ -462,6 +462,11 @@ def hostname
       @hostname ||= `hostname`.chomp
     end
 
+    # Returns PID of running worker
+    def pid
+      @pid ||= Process.pid
+    end
+
     # Returns an array of string pids of all the other workers on this
     # machine. Useful when pruning dead workers on startup.
     def worker_pids

test/worker_test.rb

@@ -312,4 +312,8 @@
     workerA.work(0)
     assert $AFTER_FORK_CALLED
   end
+
+  test "returns PID of running process" do
+    assert_equal Process.pid, @worker.pid
+  end
 end