src/mem/ruby/eventqueue/RubyEventQueue.hh

   1 /*
   2  * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
   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
  29 /*
  30  * The RubyEventQueue class implements an event queue which
  31  * can be trigger events, allowing our simulation to be event driven.
  32  *
  33  * Currently, the only event we support is a Consumer being signaled
  34  * by calling the consumer's wakeup() routine.  Adding the event to
  35  * the queue does not require a virtual function call, though calling
  36  * wakeup() is a virtual function call.
  37  *
  38  * The method triggerEvents() is called with a global time.  All
  39  * events which are before or at this time are triggered in timestamp
  40  * order.  No ordering is enforced for events scheduled to occur at
  41  * the same time.  Events scheduled to wakeup the same consumer at the
  42  * same time are combined into a single event.
  43  *
  44  * The method scheduleConsumerWakeup() is called with a global time
  45  * and a consumer pointer.  The event queue will call the wakeup()
  46  * method of the consumer at the appropriate time.
  47  *
  48  * This implementation of RubyEventQueue uses a dynamically sized array
  49  * managed as a heap.  The algorithms used has O(lg n) for insert and
  50  * O(lg n) for extract minimum element. (Based on chapter 7 of Cormen,
  51  * Leiserson, and Rivest.)  The array is dynamically sized and is
  52  * automatically doubled in size when necessary.
  53  *
  54  */
  55
  56 #ifndef __MEM_RUBY_EVENTQUEUE_RUBYEVENTQUEUE_HH__
  57 #define __MEM_RUBY_EVENTQUEUE_RUBYEVENTQUEUE_HH__
  58
  59 #include <iostream>
  60
  61 #include "config/no_vector_bounds_checks.hh"
  62 #include "mem/ruby/common/Global.hh"
  63 #include "sim/eventq.hh"
  64
  65 class Consumer;
  66 class RubyEventQueueNode;
  67
  68 class RubyEventQueue : public EventManager
  69 {
  70   public:
  71     RubyEventQueue(EventQueue* eventq, Tick _clock);
  72     ~RubyEventQueue();
  73
  74     Time getTime() const { return curTick()/m_clock; }
  75     Tick getClock() const { return m_clock; }
  76     void scheduleEvent(Consumer* consumer, Time timeDelta);
  77     void scheduleEventAbsolute(Consumer* consumer, Time timeAbs);
  78     void print(std::ostream& out) const;
  79
  80     void triggerEvents(Time t) { assert(0); }
  81     void triggerAllEvents() { assert(0); }
  82
  83   private:
  84     // Private copy constructor and assignment operator
  85     RubyEventQueue(const RubyEventQueue& obj);
  86     RubyEventQueue& operator=(const RubyEventQueue& obj);
  87
  88     // Data Members (m_ prefix)
  89     Tick m_clock;
  90 };
  91
  92 inline std::ostream&
  93 operator<<(std::ostream& out, const RubyEventQueue& obj)
  94 {
  95     obj.print(out);
  96     out << std::flush;
  97     return out;
  98 }
  99
 100 #endif // __MEM_RUBY_EVENTQUEUE_RUBYEVENTQUEUE_HH__