callback.hh revision 1094 
14484Sbinkertn@umich.edu/*
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284484Sbinkertn@umich.edu
294484Sbinkertn@umich.edu#ifndef __CALLBACK_HH__
304484Sbinkertn@umich.edu#define __CALLBACK_HH__
314484Sbinkertn@umich.edu
324484Sbinkertn@umich.edu#include <list>
334484Sbinkertn@umich.edu
344484Sbinkertn@umich.edu/**
354484Sbinkertn@umich.edu * Generic callback class.  This base class provides a virutal process
364484Sbinkertn@umich.edu * function that gets called when the callback queue is processed.
374484Sbinkertn@umich.edu */
384484Sbinkertn@umich.educlass Callback
394484Sbinkertn@umich.edu{
404484Sbinkertn@umich.edu  public:
414484Sbinkertn@umich.edu    /**
424484Sbinkertn@umich.edu     * virtualize the destructor to make sure that the correct one
434484Sbinkertn@umich.edu     * gets called.
444484Sbinkertn@umich.edu     */
454484Sbinkertn@umich.edu    virtual ~Callback() {}
464484Sbinkertn@umich.edu
474484Sbinkertn@umich.edu    /**
484484Sbinkertn@umich.edu     * virtual process function that is invoked when the callback
494484Sbinkertn@umich.edu     * queue is executed.
504484Sbinkertn@umich.edu     */
514484Sbinkertn@umich.edu    virtual void process() = 0;
52};
53
54class CallbackQueue
55{
56  protected:
57    /**
58     * Simple typedef for the data structure that stores all of the
59     * callbacks.
60     */
61    typedef std::list<Callback *> queue;
62
63    /**
64     * List of all callbacks.  To be called in fifo order.
65     */
66    queue callbacks;
67
68  public:
69    /**
70     * Add a callback to the end of the queue
71     * @param callback the callback to be added to the queue
72     */
73    void add(Callback *callback)
74    {
75        callbacks.push_back(callback);
76    }
77
78    /**
79     * Find out if there are any callbacks in the queue
80     */
81    bool empty() const { return callbacks.empty(); }
82
83    /**
84     * process all callbacks
85     */
86    void process()
87    {
88        queue::iterator i = callbacks.begin();
89        queue::iterator end = callbacks.end();
90
91        while (i != end) {
92            (*i)->process();
93            ++i;
94        }
95    }
96
97    /**
98     * clear the callback queue
99     */
100    void clear()
101    {
102        callbacks.clear();
103    }
104};
105
106template <class T, void (T::* F)()>
107class MakeCallback : public Callback
108{
109  private:
110    T *object;
111
112  public:
113    MakeCallback(T *o)
114    : object(o)
115    { }
116    void process() { (object->*F)(); }
117};
118
119#endif // __CALLBACK_HH__
120