headers/os/app/MessageQueue.h

   1 /*
   2  * Copyright 2001-2014 Haiku, Inc. All rights reserved.
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #ifndef _MESSAGE_QUEUE_H
   6 #define _MESSAGE_QUEUE_H
   7
   8
   9 #include <Locker.h>
  10 #include <Message.h>
  11         // For convenience
  12
  13
  14 class BMessageQueue {
  15 public:
  16                                                                 BMessageQueue();
  17         virtual                                         ~BMessageQueue();
  18
  19                         void                            AddMessage(BMessage* message);
  20                         void                            RemoveMessage(BMessage* message);
  21
  22                         int32                           CountMessages() const;
  23                         bool                            IsEmpty() const;
  24
  25                         BMessage*                       FindMessage(int32 index) const;
  26                         BMessage*                       FindMessage(uint32 what, int32 index = 0) const;
  27
  28                         bool                            Lock();
  29                         void                            Unlock();
  30                         bool                            IsLocked() const;
  31
  32                         BMessage*                       NextMessage();
  33                         bool                            IsNextMessage(const BMessage* message) const;
  34
  35 private:
  36                         // Reserved space in the vtable for future changes to BMessageQueue
  37         virtual void                            _ReservedMessageQueue1();
  38         virtual void                            _ReservedMessageQueue2();
  39         virtual void                            _ReservedMessageQueue3();
  40
  41                                                                 BMessageQueue(const BMessageQueue &);
  42                         BMessageQueue&          operator=(const BMessageQueue &);
  43
  44                         bool                            IsLocked();
  45                                 // this needs to be exported for R5 compatibility and should
  46                                 // be dropped as soon as possible
  47
  48 private:
  49                         BMessage*                       fHead;
  50                         BMessage*                       fTail;
  51                         int32                           fMessageCount;
  52         mutable BLocker                         fLock;
  53
  54                         uint32                          _reserved[3];
  55 };
  56
  57
  58 #endif  // _MESSAGE_QUEUE_H