text: /*
   * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
   * 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.
   */
  
  /*
   * Unordered buffer of messages that can be inserted such
   * that they can be dequeued after a given delta time has expired.
   */
  
  #ifndef __MEM_RUBY_BUFFERS_MESSAGEBUFFER_HH__
  #define __MEM_RUBY_BUFFERS_MESSAGEBUFFER_HH__
  
  #include <algorithm>
  #include <cassert>
  #include <functional>
  #include <iostream>
  #include <string>
  #include <vector>
  
  #include "mem/packet.hh"
  #include "mem/ruby/buffers/MessageBufferNode.hh"
  #include "mem/ruby/common/Address.hh"
  #include "mem/ruby/common/Consumer.hh"
  #include "mem/ruby/slicc_interface/Message.hh"
  
  class MessageBuffer
  {
    public:
      MessageBuffer(const std::string &name = "");
  
      std::string name() const { return m_name; }
  
      void setRecycleLatency(Cycles recycle_latency)
      { m_recycle_latency = recycle_latency; }
  
      void reanalyzeMessages(const Address& addr);
      void reanalyzeAllMessages();
      void stallMessage(const Address& addr);
  
      // TRUE if head of queue timestamp <= SystemTime
      bool isReady() const;
  
      void
      delayHead()
      {
          MessageBufferNode node = m_prio_heap.front();
          std::pop_heap(m_prio_heap.begin(), m_prio_heap.end(),
                        std::greater<MessageBufferNode>());
          m_prio_heap.pop_back();
          enqueue(node.m_msgptr, Cycles(1));
      }
  
      bool areNSlotsAvailable(int n);
      int getPriority() { return m_priority_rank; }
      void setPriority(int rank) { m_priority_rank = rank; }
      void setConsumer(Consumer* consumer)
      {
          if (m_consumer != NULL) {
              fatal("Trying to connect %s to MessageBuffer %s. \
                    \n%s already connected. Check the cntrl_id's.\n",
                    *consumer, *this, *m_consumer);
          }
          m_consumer = consumer;
      }
  
      void setSender(ClockedObject* obj)
      {
          assert(m_sender == NULL || m_sender == obj);
          m_sender = obj;
      }
  
      void setReceiver(ClockedObject* obj)
      {
          assert(m_receiver == NULL || m_receiver == obj);
          m_receiver = obj;
      }
  
      void setDescription(const std::string& name) { m_name = name; }
      std::string getDescription() { return m_name;}
  
      Consumer* getConsumer() { return m_consumer; }
  
      const Message* peekAtHeadOfQueue() const;
      const Message* peek() const { return peekAtHeadOfQueue(); }
      const MsgPtr getMsgPtrCopy() const;
  
      const MsgPtr&
      peekMsgPtr() const
      {
          assert(isReady());
          return m_prio_heap.front().m_msgptr;
      }
  
      const MsgPtr&
      peekMsgPtrEvenIfNotReady() const
      {
          return m_prio_heap.front().m_msgptr;
      }
  
      void enqueue(MsgPtr message) { enqueue(message, Cycles(1)); }
      void enqueue(MsgPtr message, Cycles delta);
  
      //!  returns delay ticks of the message.
      Cycles dequeue_getDelayCycles(MsgPtr& message);
      void dequeue(MsgPtr& message);
  
      //! returns delay cycles of the message
      Cycles dequeue_getDelayCycles();
      void dequeue() { pop(); }
      void pop();
      void recycle();
      bool isEmpty() const { return m_prio_heap.size() == 0; }
  
      void
      setOrdering(bool order)
      {
          m_strict_fifo = order;
          m_ordering_set = true;
      }
      void resize(int size) { m_max_size = size; }
      int getSize();
      void setRandomization(bool random_flag) { m_randomization = random_flag; }
  
      void clear();
  
      void print(std::ostream& out) const;
      void printStats(std::ostream& out);
      void clearStats() { m_not_avail_count = 0; m_msg_counter = 0; }
  
      void setIncomingLink(int link_id) { m_input_link_id = link_id; }
      void setVnet(int net) { m_vnet_id = net; }
  
      // Function for figuring out if any of the messages in the buffer can
      // satisfy the read request for the address in the packet.
      // Return value, if true, indicates that the request was fulfilled.
      bool functionalRead(Packet *pkt);
  
      // Function for figuring out if any of the messages in the buffer need
      // to be updated with the data from the packet.
      // Return value indicates the number of messages that were updated.
      // This required for debugging the code.
      uint32_t functionalWrite(Packet *pkt);
  
    private:
      //added by SS
      Cycles m_recycle_latency;
  
      // Private Methods
      Cycles setAndReturnDelayCycles(MsgPtr message);
  
      // Private copy constructor and assignment operator
      MessageBuffer(const MessageBuffer& obj);
      MessageBuffer& operator=(const MessageBuffer& obj);
  
      // Data Members (m_ prefix)
      //! The two ends of the buffer.
      ClockedObject* m_sender;
      ClockedObject* m_receiver;
  
      //! Consumer to signal a wakeup(), can be NULL
      Consumer* m_consumer;
      std::vector<MessageBufferNode> m_prio_heap;
  
      // use a std::map for the stalled messages as this container is
      // sorted and ensures a well-defined iteration order
      typedef std::map< Address, std::list<MsgPtr> > StallMsgMapType;
      typedef std::vector<MsgPtr>::iterator MsgListIter;
  
      StallMsgMapType m_stall_msg_map;
      std::string m_name;
  
      int m_max_size;
      int m_size;
  
      Cycles m_time_last_time_size_checked;
      int m_size_last_time_size_checked;
  
      // variables used so enqueues appear to happen imediately, while
      // pop happen the next cycle
      Cycles m_time_last_time_enqueue;
      Cycles m_time_last_time_pop;
      int m_size_at_cycle_start;
      int m_msgs_this_cycle;
  
      int m_not_avail_count;  // count the # of times I didn't have N
                              // slots available
      uint64 m_msg_counter;
      int m_priority_rank;
      bool m_strict_fifo;
      bool m_ordering_set;
      bool m_randomization;
  
      Tick m_last_arrival_time;
  
      int m_input_link_id;
      int m_vnet_id;
  };
  
  Cycles random_time();
  
  inline std::ostream&
  operator<<(std::ostream& out, const MessageBuffer& obj)
  {
      obj.print(out);
      out << std::flush;
      return out;
  }
  
  #endif // __MEM_RUBY_BUFFERS_MESSAGEBUFFER_HH__
  