1/*
2 * Copyright (c) 2003-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Nathan Binkert
29 */
30
31#ifndef __CALLBACK_HH__
32#define __CALLBACK_HH__
33
34#include <list>
35
36/**
37 * Generic callback class. This base class provides a virtual process
38 * function that gets called when the callback queue is processed.
39 */
40class Callback
41{
42 public:
43 /**
44 * virtualize the destructor to make sure that the correct one
45 * gets called.
46 */
47 virtual ~Callback() {}
48
49 /**
50 * virtual process function that is invoked when the callback
51 * queue is executed.
52 */
53 virtual void process() = 0;
54};
55
56class CallbackQueue
57{
58 protected:
59 /**
60 * Simple typedef for the data structure that stores all of the
61 * callbacks.
62 */
63 typedef std::list<Callback *> queue;
64
65 /**
66 * List of all callbacks. To be called in fifo order.
67 */
68 queue callbacks;
69
70 public:
71 /**
72 * Add a callback to the end of the queue
73 * @param callback the callback to be added to the queue
74 */
75 void add(Callback *callback)
76 {
77 callbacks.push_back(callback);
78 }
79
80 /**
81 * Find out if there are any callbacks in the queue
82 */
83 bool empty() const { return callbacks.empty(); }
84
85 /**
86 * process all callbacks
87 */
88 void process()
89 {
90 queue::iterator i = callbacks.begin();
91 queue::iterator end = callbacks.end();
92
93 while (i != end) {
94 (*i)->process();
95 ++i;
96 }
97 }
98
99 /**
100 * clear the callback queue
101 */
102 void clear()
103 {
104 callbacks.clear();
105 }
106};
107
108/// Helper template class to turn a simple class member function into
109/// a callback.
110template <class T, void (T::* F)()>
111class MakeCallback : public Callback
112{
113 private:
114 T *object;
115
116 public:
117 MakeCallback(T *o)
118 : object(o)
119 { }
120
121 void process() { (object->*F)(); }
122};
123
124#endif // __CALLBACK_HH__