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Diffstat (limited to 'src/base/callback.hh')
-rw-r--r-- | src/base/callback.hh | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/src/base/callback.hh b/src/base/callback.hh new file mode 100644 index 000000000..7b3023505 --- /dev/null +++ b/src/base/callback.hh @@ -0,0 +1,122 @@ +/* + * Copyright (c) 2003-2005 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef __CALLBACK_HH__ +#define __CALLBACK_HH__ + +#include <list> + +/** + * Generic callback class. This base class provides a virtual process + * function that gets called when the callback queue is processed. + */ +class Callback +{ + public: + /** + * virtualize the destructor to make sure that the correct one + * gets called. + */ + virtual ~Callback() {} + + /** + * virtual process function that is invoked when the callback + * queue is executed. + */ + virtual void process() = 0; +}; + +class CallbackQueue +{ + protected: + /** + * Simple typedef for the data structure that stores all of the + * callbacks. + */ + typedef std::list<Callback *> queue; + + /** + * List of all callbacks. To be called in fifo order. + */ + queue callbacks; + + public: + /** + * Add a callback to the end of the queue + * @param callback the callback to be added to the queue + */ + void add(Callback *callback) + { + callbacks.push_back(callback); + } + + /** + * Find out if there are any callbacks in the queue + */ + bool empty() const { return callbacks.empty(); } + + /** + * process all callbacks + */ + void process() + { + queue::iterator i = callbacks.begin(); + queue::iterator end = callbacks.end(); + + while (i != end) { + (*i)->process(); + ++i; + } + } + + /** + * clear the callback queue + */ + void clear() + { + callbacks.clear(); + } +}; + +/// Helper template class to turn a simple class member function into +/// a callback. +template <class T, void (T::* F)()> +class MakeCallback : public Callback +{ + private: + T *object; + + public: + MakeCallback(T *o) + : object(o) + { } + + void process() { (object->*F)(); } +}; + +#endif // __CALLBACK_HH__ |