1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MOJO_SYSTEM_MESSAGE_QUEUE_H_ 6 #define MOJO_SYSTEM_MESSAGE_QUEUE_H_ 7 8 #include <deque> 9 10 #include "base/macros.h" 11 #include "base/memory/scoped_ptr.h" 12 #include "mojo/system/message_in_transit.h" 13 #include "mojo/system/system_impl_export.h" 14 15 namespace mojo { 16 namespace system { 17 18 // A simple queue for |MessageInTransit|s (that owns its messages). 19 // This class is not thread-safe. 20 // TODO(vtl): Write tests. 21 class MOJO_SYSTEM_IMPL_EXPORT MessageInTransitQueue { 22 public: 23 MessageInTransitQueue(); 24 ~MessageInTransitQueue(); 25 IsEmpty()26 bool IsEmpty() const { return queue_.empty(); } 27 AddMessage(scoped_ptr<MessageInTransit> message)28 void AddMessage(scoped_ptr<MessageInTransit> message) { 29 queue_.push_back(message.release()); 30 } 31 GetMessage()32 scoped_ptr<MessageInTransit> GetMessage() { 33 MessageInTransit* rv = queue_.front(); 34 queue_.pop_front(); 35 return make_scoped_ptr(rv); 36 } 37 PeekMessage()38 MessageInTransit* PeekMessage() { return queue_.front(); } 39 DiscardMessage()40 void DiscardMessage() { 41 delete queue_.front(); 42 queue_.pop_front(); 43 } 44 45 void Clear(); 46 47 // Efficiently swaps contents with |*other|. 48 void Swap(MessageInTransitQueue* other); 49 50 private: 51 // TODO(vtl): When C++11 is available, switch this to a deque of 52 // |scoped_ptr|/|unique_ptr|s. 53 std::deque<MessageInTransit*> queue_; 54 55 DISALLOW_COPY_AND_ASSIGN(MessageInTransitQueue); 56 }; 57 58 } // namespace system 59 } // namespace mojo 60 61 #endif // MOJO_SYSTEM_MESSAGE_QUEUE_H_ 62