src/mem/ruby/eventqueue/RubyEventQueue.hh

   1
   2 /*
   3  * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met: redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer;
  10  * redistributions in binary form must reproduce the above copyright
  11  * notice, this list of conditions and the following disclaimer in the
  12  * documentation and/or other materials provided with the distribution;
  13  * neither the name of the copyright holders nor the names of its
  14  * contributors may be used to endorse or promote products derived from
  15  * this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  20  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  23  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * $Id$
  32  *
  33  * Description: The EventQueue class implements an event queue which
  34  * can be trigger events, allowing our simulation to be event driven.
  35  *
  36  * Currently, the only event we support is a Consumer being signaled
  37  * by calling the consumer's wakeup() routine.  Adding the event to
  38  * the queue does not require a virtual function call, though calling
  39  * wakeup() is a virtual function call.
  40  *
  41  * The method triggerEvents() is called with a global time.  All
  42  * events which are before or at this time are triggered in timestamp
  43  * order.  No ordering is enforced for events scheduled to occur at
  44  * the same time.  Events scheduled to wakeup the same consumer at the
  45  * same time are combined into a single event.
  46  *
  47  * The method scheduleConsumerWakeup() is called with a global time
  48  * and a consumer pointer.  The event queue will call the wakeup()
  49  * method of the consumer at the appropriate time.
  50  *
  51  * This implementation of EventQueue uses a dynamically sized array
  52  * managed as a heap.  The algorithms used has O(lg n) for insert and
  53  * O(lg n) for extract minimum element. (Based on chapter 7 of Cormen,
  54  * Leiserson, and Rivest.)  The array is dynamically sized and is
  55  * automatically doubled in size when necessary.
  56  *
  57  */
  58
  59 #ifndef RUBYEVENTQUEUE_H
  60 #define RUBYEVENTQUEUE_H
  61
  62 #include "Global.hh"
  63 #include "Vector.hh"
  64
  65 class Consumer;
  66 template <class TYPE> class PrioHeap;
  67 class RubyEventQueueNode;
  68
  69 class RubyEventQueue {
  70 public:
  71   // Constructors
  72   RubyEventQueue();
  73
  74   // Destructor
  75   ~RubyEventQueue();
  76
  77   // Public Methods
  78
  79   Time getTime() const { return m_globalTime; }
  80   void scheduleEvent(Consumer* consumer, Time timeDelta) { scheduleEventAbsolute(consumer, timeDelta + m_globalTime); }
  81   void scheduleEventAbsolute(Consumer* consumer, Time timeAbs);
  82   void triggerEvents(Time t); // called to handle all events <= time t
  83   void triggerAllEvents();
  84   void print(ostream& out) const;
  85   bool isEmpty() const;
  86
  87   Time getTimeOfLastRecovery() {return m_timeOfLastRecovery;}
  88   void setTimeOfLastRecovery(Time t) {m_timeOfLastRecovery = t;}
  89
  90   // Private Methods
  91 private:
  92   // Private copy constructor and assignment operator
  93   void init();
  94   RubyEventQueue(const RubyEventQueue& obj);
  95   RubyEventQueue& operator=(const RubyEventQueue& obj);
  96
  97   // Data Members (m_ prefix)
  98   PrioHeap<RubyEventQueueNode>* m_prio_heap_ptr;
  99   Time m_globalTime;
 100   Time m_timeOfLastRecovery;
 101 };
 102
 103 // Output operator declaration
 104 inline extern
 105 ostream& operator<<(ostream& out, const RubyEventQueue& obj);
 106
 107 // ******************* Definitions *******************
 108
 109 // Output operator definition
 110 inline extern
 111 ostream& operator<<(ostream& out, const RubyEventQueue& obj)
 112 {
 113   obj.print(out);
 114   out << flush;
 115   return out;
 116 }
 117
 118 #endif //EVENTQUEUE_H