1 files changed, 101 insertions, 0 deletions
diff --git a/qpid/ruby/lib/qpid/queue.rb b/qpid/ruby/lib/qpid/queue.rb
new file mode 100644
index 0000000000..4150173b53
--- /dev/null
+++ b/qpid/ruby/lib/qpid/queue.rb
@@ -0,0 +1,101 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+# Augment the standard python multithreaded Queue implementation to add a
+# close() method so that threads blocking on the content of a queue can be
+# notified if the queue is no longer in use.
+
+require 'thread'
+
+# Python nominally uses a bounded queue, but the code never establishes
+# a maximum size; we therefore use Ruby's unbounded queue
+class Qpid::Queue < ::Queue
+
+  DONE = Object.new
+  STOP = Object.new
+
+  def initialize
+    super
+    @error = nil
+    @listener = nil
+    @exc_listener = nil
+    @exc_listener_lock = Monitor.new
+    @thread = nil
+  end
+
+  def close(error = nil)
+    @error = error
+    put(DONE)
+    unless @thread.nil?
+      @thread.join()
+      @thread = nil
+    end
+  end
+
+  def get(block = true, timeout = nil)
+    unless timeout.nil?
+      raise NotImplementedError
+    end
+    result = pop(! block)
+    if result == DONE
+      # this guarantees that any other waiting threads or any future
+      # calls to get will also result in a Qpid::Closed exception
+      put(DONE)
+      raise Qpid::Closed.new(@error)
+    else
+      return result
+    end
+  end
+
+  alias :put :push
+
+  def exc_listen(&block)
+    @exc_listener_lock.synchronize do
+      @exc_listener = block
+    end
+  end
+
+  def listen(&block)
+    if ! block_given? && @thread
+      put(STOP)
+      @thread.join()
+      @thread = nil
+    end
+
+    # FIXME: There is a potential race since we could be changing one
+    # non-nil listener to another
+    @listener = block
+
+    if block_given? && @thread.nil?
+      @thread = Thread.new do
+        loop do
+          begin
+            o = get()
+            break if o == STOP
+            @listener.call(o)
+          rescue Qpid::Closed => e
+            @exc_listener.call(e) if @exc_listener
+            break
+          end
+        end
+      end
+    end
+  end
+
+end