1 /*
2  * Copyright (C) 2002-2003 Fhg Fokus
3  *
4  * This file is part of SEMS, a free SIP media server.
5  *
6  * SEMS is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version. This program is released under
10  * the GPL with the additional exemption that compiling, linking,
11  * and/or using OpenSSL is allowed.
12  *
13  * For a license to use the SEMS software under conditions
14  * other than those described here, or to purchase support for this
15  * software, please contact iptel.org by e-mail at the following addresses:
16  *    info@iptel.org
17  *
18  * SEMS is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
26  */
27 /** @file AmEventQueue.h */
28 #ifndef _AMEVENTQUEUE_H_
29 #define _AMEVENTQUEUE_H_
30 
31 #include "AmThread.h"
32 #include "AmEvent.h"
33 #include "atomic_types.h"
34 
35 #include <queue>
36 
37 class AmEventQueueInterface
38 {
39  public:
~AmEventQueueInterface()40   virtual ~AmEventQueueInterface() {}
41   virtual void postEvent(AmEvent*)=0;
42 };
43 
44 class AmEventQueue;
45 /** a receiver for notifications about
46     the fact that events are pending */
47 class AmEventNotificationSink
48 {
49  public:
~AmEventNotificationSink()50   virtual ~AmEventNotificationSink() { }
51   virtual void notify(AmEventQueue* sender) = 0;
52 };
53 
54 /**
55  * \brief Asynchronous event queue implementation
56  *
57  * This class implements an event queue; a queue into which
58  * \ref AmEvent can safely be posted at any time from any
59  * thread, which are then processed by the registered event
60  *  handler.
61  */
62 class AmEventQueue
63   : public AmEventQueueInterface,
64     public atomic_ref_cnt
65 {
66 protected:
67   AmEventHandler*           handler;
68   AmEventNotificationSink*  wakeup_handler;
69 
70   std::queue<AmEvent*>      ev_queue;
71   AmMutex                   m_queue;
72   AmCondition<bool>         ev_pending;
73 
74   bool finalized;
75 
76 public:
77   AmEventQueue(AmEventHandler* handler);
78   virtual ~AmEventQueue();
79 
80   void postEvent(AmEvent*);
81   void processEvents();
82   void waitForEvent();
83   void processSingleEvent();
84   bool eventPending();
85 
86   void setEventNotificationSink(AmEventNotificationSink* _wakeup_handler);
87 
is_finalized()88   bool is_finalized() { return finalized; }
89 
90   // return true to continue processing
startup()91   virtual bool startup() { return true; }
processingCycle()92   virtual bool processingCycle() { processEvents(); return true; }
finalize()93   virtual void finalize() { finalized = true; }
94 };
95 
96 #endif
97 
98