1 files changed, 69 insertions, 0 deletions
diff --git a/chromium/mojo/system/message_in_transit_queue.h b/chromium/mojo/system/message_in_transit_queue.h
new file mode 100644
index 00000000000..a70a7ef742b
--- /dev/null
+++ b/chromium/mojo/system/message_in_transit_queue.h
@@ -0,0 +1,69 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MOJO_SYSTEM_MESSAGE_QUEUE_H_
+#define MOJO_SYSTEM_MESSAGE_QUEUE_H_
+
+#include <deque>
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "mojo/system/message_in_transit.h"
+#include "mojo/system/system_impl_export.h"
+
+namespace mojo {
+namespace system {
+
+// A simple queue for |MessageInTransit|s (that owns its messages).
+// This class is not thread-safe.
+// TODO(vtl): Write tests.
+class MOJO_SYSTEM_IMPL_EXPORT MessageInTransitQueue {
+ public:
+  MessageInTransitQueue();
+
+  struct PassContents {};
+  // Constructor that takes over the contents of another
+  // |MessageInTransitQueue|, leaving it empty.
+  MessageInTransitQueue(PassContents, MessageInTransitQueue* other);
+
+  ~MessageInTransitQueue();
+
+  bool IsEmpty() const {
+    return queue_.empty();
+  }
+
+  void AddMessage(scoped_ptr<MessageInTransit> message) {
+    queue_.push_back(message.release());
+  }
+
+  scoped_ptr<MessageInTransit> GetMessage() {
+    MessageInTransit* rv = queue_.front();
+    queue_.pop_front();
+    return make_scoped_ptr(rv);
+  }
+
+  MessageInTransit* PeekMessage() {
+    return queue_.front();
+  }
+
+  void DiscardMessage() {
+    delete queue_.front();
+    queue_.pop_front();
+  }
+
+  void Clear();
+
+ private:
+  // TODO(vtl): When C++11 is available, switch this to a deque of
+  // |scoped_ptr|/|unique_ptr|s.
+  std::deque<MessageInTransit*> queue_;
+
+  DISALLOW_COPY_AND_ASSIGN(MessageInTransitQueue);
+};
+
+
+}  // namespace system
+}  // namespace mojo
+
+#endif  // MOJO_SYSTEM_MESSAGE_QUEUE_H_