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1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 : /*
3 : * This file is part of the LibreOffice project.
4 : *
5 : * This Source Code Form is subject to the terms of the Mozilla Public
6 : * License, v. 2.0. If a copy of the MPL was not distributed with this
7 : * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8 : *
9 : * This file incorporates work covered by the following license notice:
10 : *
11 : * Licensed to the Apache Software Foundation (ASF) under one or more
12 : * contributor license agreements. See the NOTICE file distributed
13 : * with this work for additional information regarding copyright
14 : * ownership. The ASF licenses this file to you under the Apache
15 : * License, Version 2.0 (the "License"); you may not use this file
16 : * except in compliance with the License. You may obtain a copy of
17 : * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18 : */
19 :
20 : #ifndef INCLUDED_COMPHELPER_ASYNCNOTIFICATION_HXX
21 : #define INCLUDED_COMPHELPER_ASYNCNOTIFICATION_HXX
22 :
23 : #include <sal/config.h>
24 :
25 : #include <comphelper/comphelperdllapi.h>
26 : #include <rtl/ref.hxx>
27 : #include <sal/types.h>
28 : #include <salhelper/thread.hxx>
29 : #include <salhelper/simplereferenceobject.hxx>
30 : #include <memory>
31 :
32 : namespace comphelper
33 : {
34 : //= AnyEvent
35 :
36 : /** the very basic instance to hold a description of an event
37 : */
38 : class COMPHELPER_DLLPUBLIC AnyEvent : public salhelper::SimpleReferenceObject
39 : {
40 : public:
41 : AnyEvent();
42 :
43 : protected:
44 : virtual ~AnyEvent();
45 :
46 : private:
47 : AnyEvent( AnyEvent& ) SAL_DELETED_FUNCTION;
48 : void operator=( AnyEvent& ) SAL_DELETED_FUNCTION;
49 : };
50 :
51 :
52 : //= typedefs
53 :
54 : typedef ::rtl::Reference< AnyEvent > AnyEventRef;
55 :
56 :
57 : //= IEventProcessor
58 :
59 : /** an event processor
60 :
61 : @see AsyncEventNotifier
62 : */
63 143 : class SAL_NO_VTABLE IEventProcessor
64 : {
65 : public:
66 : /** process a single event
67 : */
68 : virtual void processEvent( const AnyEvent& _rEvent ) = 0;
69 :
70 : virtual void SAL_CALL acquire() throw () = 0;
71 : virtual void SAL_CALL release() throw () = 0;
72 :
73 : protected:
74 123 : ~IEventProcessor() {}
75 : };
76 :
77 :
78 : //= AsyncEventNotifier
79 :
80 : struct EventNotifierImpl;
81 :
82 : /** a helper class for notifying events asynchronously
83 :
84 : If you need to notify certain events to external components, you usually should
85 : not do this while you have mutexes locked, to prevent multi-threading issues.
86 :
87 : However, you do not always have complete control over all mutex guards on the stack.
88 : If, in such a case, the listener notification is one-way, you can decide to do it
89 : asynchronously.
90 :
91 : The ->AsyncEventNotifier helps you to process such events asynchronously. Every
92 : event is tied to an ->IEventProcessor which is responsible for processing it.
93 :
94 : The AsyncEventNotifier is implemented as a thread itself, which sleeps as long as there are no
95 : events in the queue. As soon as you add an event, the thread is woken up, processes the event,
96 : and sleeps again.
97 : */
98 : class COMPHELPER_DLLPUBLIC AsyncEventNotifier: public salhelper::Thread
99 : {
100 : friend struct EventNotifierImpl;
101 :
102 : private:
103 : std::unique_ptr<EventNotifierImpl> m_xImpl;
104 :
105 : SAL_DLLPRIVATE virtual ~AsyncEventNotifier();
106 :
107 : // Thread
108 : SAL_DLLPRIVATE virtual void execute() SAL_OVERRIDE;
109 :
110 : public:
111 : /** constructs a notifier thread
112 :
113 : @param name the thread name, see ::osl_setThreadName; must not be
114 : null
115 : */
116 : AsyncEventNotifier(char const * name);
117 :
118 : /** terminates the thread
119 :
120 : Note that this is a cooporative termination - if you call this from a thread different
121 : from the notification thread itself, then it will block until the notification thread
122 : finished processing the current event. If you call it from the notification thread
123 : itself, it will return immediately, and the thread will be terminated as soon as
124 : the current notification is finished.
125 : */
126 : virtual void SAL_CALL terminate() SAL_OVERRIDE;
127 :
128 : /** adds an event to the queue, together with the instance which is responsible for
129 : processing it
130 :
131 : @param _rEvent
132 : the event to add to the queue
133 : @param _xProcessor
134 : the processor for the event.<br/>
135 : Beware of life time issues here. If your event processor dies or becomes otherwise
136 : nonfunctional, you are responsible for removing all respective events from the queue.
137 : You can do this by calling ->removeEventsForProcessor
138 : */
139 : void addEvent( const AnyEventRef& _rEvent, const ::rtl::Reference< IEventProcessor >& _xProcessor );
140 :
141 : /** removes all events for the given event processor from the queue
142 : */
143 : void removeEventsForProcessor( const ::rtl::Reference< IEventProcessor >& _xProcessor );
144 : };
145 :
146 :
147 : //= EventHolder
148 :
149 : /** AnyEvent derivee holding an foreign event instance
150 : */
151 : template < typename EVENT_OBJECT >
152 438 : class EventHolder : public AnyEvent
153 : {
154 : public:
155 : typedef EVENT_OBJECT EventObjectType;
156 :
157 : private:
158 : EventObjectType m_aEvent;
159 :
160 : public:
161 220 : inline EventHolder( const EventObjectType& _rEvent )
162 220 : :m_aEvent( _rEvent )
163 : {
164 220 : }
165 :
166 220 : inline const EventObjectType& getEventObject() const { return m_aEvent; }
167 : };
168 :
169 :
170 : } // namespace comphelper
171 :
172 :
173 : #endif // INCLUDED_COMPHELPER_ASYNCNOTIFICATION_HXX
174 :
175 : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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