ruby: move files from ruby/system to ruby/structures

The directory ruby/system is crowded and unorganized. Hence, the files the
hold actual physical structures, are being moved to the directory
ruby/structures.  This includes Cache Memory, Directory Memory,
Memory Controller, Wire Buffer, TBE Table, Perfect Cache Memory, Timer Table,
Bank Array.

The directory ruby/systems has the glue code that holds these structures
together.

--HG--
rename : src/mem/ruby/system/MachineID.hh => src/mem/ruby/common/MachineID.hh
rename : src/mem/ruby/buffers/MessageBuffer.cc => src/mem/ruby/network/MessageBuffer.cc
rename : src/mem/ruby/buffers/MessageBuffer.hh => src/mem/ruby/network/MessageBuffer.hh
rename : src/mem/ruby/buffers/MessageBufferNode.cc => src/mem/ruby/network/MessageBufferNode.cc
rename : src/mem/ruby/buffers/MessageBufferNode.hh => src/mem/ruby/network/MessageBufferNode.hh
rename : src/mem/ruby/system/AbstractReplacementPolicy.hh => src/mem/ruby/structures/AbstractReplacementPolicy.hh
rename : src/mem/ruby/system/BankedArray.cc => src/mem/ruby/structures/BankedArray.cc
rename : src/mem/ruby/system/BankedArray.hh => src/mem/ruby/structures/BankedArray.hh
rename : src/mem/ruby/system/Cache.py => src/mem/ruby/structures/Cache.py
rename : src/mem/ruby/system/CacheMemory.cc => src/mem/ruby/structures/CacheMemory.cc
rename : src/mem/ruby/system/CacheMemory.hh => src/mem/ruby/structures/CacheMemory.hh
rename : src/mem/ruby/system/DirectoryMemory.cc => src/mem/ruby/structures/DirectoryMemory.cc
rename : src/mem/ruby/system/DirectoryMemory.hh => src/mem/ruby/structures/DirectoryMemory.hh
rename : src/mem/ruby/system/DirectoryMemory.py => src/mem/ruby/structures/DirectoryMemory.py
rename : src/mem/ruby/system/LRUPolicy.hh => src/mem/ruby/structures/LRUPolicy.hh
rename : src/mem/ruby/system/MemoryControl.cc => src/mem/ruby/structures/MemoryControl.cc
rename : src/mem/ruby/system/MemoryControl.hh => src/mem/ruby/structures/MemoryControl.hh
rename : src/mem/ruby/system/MemoryControl.py => src/mem/ruby/structures/MemoryControl.py
rename : src/mem/ruby/system/MemoryNode.cc => src/mem/ruby/structures/MemoryNode.cc
rename : src/mem/ruby/system/MemoryNode.hh => src/mem/ruby/structures/MemoryNode.hh
rename : src/mem/ruby/system/MemoryVector.hh => src/mem/ruby/structures/MemoryVector.hh
rename : src/mem/ruby/system/PerfectCacheMemory.hh => src/mem/ruby/structures/PerfectCacheMemory.hh
rename : src/mem/ruby/system/PersistentTable.cc => src/mem/ruby/structures/PersistentTable.cc
rename : src/mem/ruby/system/PersistentTable.hh => src/mem/ruby/structures/PersistentTable.hh
rename : src/mem/ruby/system/PseudoLRUPolicy.hh => src/mem/ruby/structures/PseudoLRUPolicy.hh
rename : src/mem/ruby/system/RubyMemoryControl.cc => src/mem/ruby/structures/RubyMemoryControl.cc
rename : src/mem/ruby/system/RubyMemoryControl.hh => src/mem/ruby/structures/RubyMemoryControl.hh
rename : src/mem/ruby/system/RubyMemoryControl.py => src/mem/ruby/structures/RubyMemoryControl.py
rename : src/mem/ruby/system/SparseMemory.cc => src/mem/ruby/structures/SparseMemory.cc
rename : src/mem/ruby/system/SparseMemory.hh => src/mem/ruby/structures/SparseMemory.hh
rename : src/mem/ruby/system/TBETable.hh => src/mem/ruby/structures/TBETable.hh
rename : src/mem/ruby/system/TimerTable.cc => src/mem/ruby/structures/TimerTable.cc
rename : src/mem/ruby/system/TimerTable.hh => src/mem/ruby/structures/TimerTable.hh
rename : src/mem/ruby/system/WireBuffer.cc => src/mem/ruby/structures/WireBuffer.cc
rename : src/mem/ruby/system/WireBuffer.hh => src/mem/ruby/structures/WireBuffer.hh
rename : src/mem/ruby/system/WireBuffer.py => src/mem/ruby/structures/WireBuffer.py
rename : src/mem/ruby/recorder/CacheRecorder.cc => src/mem/ruby/system/CacheRecorder.cc
rename : src/mem/ruby/recorder/CacheRecorder.hh => src/mem/ruby/system/CacheRecorder.hh

12 files changed, 760 insertions, 7 deletions

diff --git a/src/mem/ruby/network/MessageBuffer.cc b/src/mem/ruby/network/MessageBuffer.cc
new file mode 100644
index 000000000..1961765c5
--- /dev/null
+++ b/src/mem/ruby/network/MessageBuffer.cc
@@ -0,0 +1,422 @@
+/*
+ * 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.
+ */
+
+#include <cassert>
+
+#include "base/cprintf.hh"
+#include "base/misc.hh"
+#include "base/stl_helpers.hh"
+#include "debug/RubyQueue.hh"
+#include "mem/ruby/network/MessageBuffer.hh"
+#include "mem/ruby/system/System.hh"
+
+using namespace std;
+using m5::stl_helpers::operator<<;
+
+MessageBuffer::MessageBuffer(const string &name)
+    : m_time_last_time_size_checked(0), m_time_last_time_enqueue(0),
+    m_time_last_time_pop(0), m_last_arrival_time(0)
+{
+    m_msg_counter = 0;
+    m_consumer = NULL;
+    m_sender = NULL;
+    m_receiver = NULL;
+
+    m_ordering_set = false;
+    m_strict_fifo = true;
+    m_max_size = 0;
+    m_randomization = true;
+    m_size_last_time_size_checked = 0;
+    m_size_at_cycle_start = 0;
+    m_msgs_this_cycle = 0;
+    m_not_avail_count = 0;
+    m_priority_rank = 0;
+    m_name = name;
+
+    m_stall_msg_map.clear();
+    m_input_link_id = 0;
+    m_vnet_id = 0;
+}
+
+unsigned int
+MessageBuffer::getSize()
+{
+    if (m_time_last_time_size_checked != m_receiver->curCycle()) {
+        m_time_last_time_size_checked = m_receiver->curCycle();
+        m_size_last_time_size_checked = m_prio_heap.size();
+    }
+
+    return m_size_last_time_size_checked;
+}
+
+bool
+MessageBuffer::areNSlotsAvailable(unsigned int n)
+{
+
+    // fast path when message buffers have infinite size
+    if (m_max_size == 0) {
+        return true;
+    }
+
+    // determine the correct size for the current cycle
+    // pop operations shouldn't effect the network's visible size
+    // until next cycle, but enqueue operations effect the visible
+    // size immediately
+    unsigned int current_size = 0;
+
+    if (m_time_last_time_pop < m_sender->clockEdge()) {
+        // no pops this cycle - heap size is correct
+        current_size = m_prio_heap.size();
+    } else {
+        if (m_time_last_time_enqueue < m_sender->curCycle()) {
+            // no enqueues this cycle - m_size_at_cycle_start is correct
+            current_size = m_size_at_cycle_start;
+        } else {
+            // both pops and enqueues occured this cycle - add new
+            // enqueued msgs to m_size_at_cycle_start
+            current_size = m_size_at_cycle_start + m_msgs_this_cycle;
+        }
+    }
+
+    // now compare the new size with our max size
+    if (current_size + n <= m_max_size) {
+        return true;
+    } else {
+        DPRINTF(RubyQueue, "n: %d, current_size: %d, heap size: %d, "
+                "m_max_size: %d\n",
+                n, current_size, m_prio_heap.size(), m_max_size);
+        m_not_avail_count++;
+        return false;
+    }
+}
+
+const Message*
+MessageBuffer::peek() const
+{
+    DPRINTF(RubyQueue, "Peeking at head of queue.\n");
+    assert(isReady());
+
+    const Message* msg_ptr = m_prio_heap.front().m_msgptr.get();
+    assert(msg_ptr);
+
+    DPRINTF(RubyQueue, "Message: %s\n", (*msg_ptr));
+    return msg_ptr;
+}
+
+// FIXME - move me somewhere else
+Cycles
+random_time()
+{
+    Cycles time(1);
+    time += Cycles(random() & 0x3);  // [0...3]
+    if ((random() & 0x7) == 0) {  // 1 in 8 chance
+        time += Cycles(100 + (random() % 0xf)); // 100 + [1...15]
+    }
+    return time;
+}
+
+void
+MessageBuffer::enqueue(MsgPtr message, Cycles delta)
+{
+    m_msg_counter++;
+
+    // record current time incase we have a pop that also adjusts my size
+    if (m_time_last_time_enqueue < m_sender->curCycle()) {
+        m_msgs_this_cycle = 0;  // first msg this cycle
+        m_time_last_time_enqueue = m_sender->curCycle();
+    }
+    m_msgs_this_cycle++;
+
+    assert(m_ordering_set);
+
+    // Calculate the arrival time of the message, that is, the first
+    // cycle the message can be dequeued.
+    assert(delta > 0);
+    Tick current_time = m_sender->clockEdge();
+    Tick arrival_time = 0;
+
+    if (!RubySystem::getRandomization() || !m_randomization) {
+        // No randomization
+        arrival_time = current_time + delta * m_sender->clockPeriod();
+    } else {
+        // Randomization - ignore delta
+        if (m_strict_fifo) {
+            if (m_last_arrival_time < current_time) {
+                m_last_arrival_time = current_time;
+            }
+            arrival_time = m_last_arrival_time +
+                           random_time() * m_sender->clockPeriod();
+        } else {
+            arrival_time = current_time +
+                           random_time() * m_sender->clockPeriod();
+        }
+    }
+
+    // Check the arrival time
+    assert(arrival_time > current_time);
+    if (m_strict_fifo) {
+        if (arrival_time < m_last_arrival_time) {
+            panic("FIFO ordering violated: %s name: %s current time: %d "
+                  "delta: %d arrival_time: %d last arrival_time: %d\n",
+                  *this, m_name, current_time,
+                  delta * m_sender->clockPeriod(),
+                  arrival_time, m_last_arrival_time);
+        }
+    }
+
+    // If running a cache trace, don't worry about the last arrival checks
+    if (!g_system_ptr->m_warmup_enabled) {
+        m_last_arrival_time = arrival_time;
+    }
+
+    // compute the delay cycles and set enqueue time
+    Message* msg_ptr = message.get();
+    assert(msg_ptr != NULL);
+
+    assert(m_sender->clockEdge() >= msg_ptr->getLastEnqueueTime() &&
+           "ensure we aren't dequeued early");
+
+    msg_ptr->updateDelayedTicks(m_sender->clockEdge());
+    msg_ptr->setLastEnqueueTime(arrival_time);
+
+    // Insert the message into the priority heap
+    MessageBufferNode thisNode(arrival_time, m_msg_counter, message);
+    m_prio_heap.push_back(thisNode);
+    push_heap(m_prio_heap.begin(), m_prio_heap.end(),
+        greater<MessageBufferNode>());
+
+    DPRINTF(RubyQueue, "Enqueue arrival_time: %lld, Message: %s\n",
+            arrival_time, *(message.get()));
+
+    // Schedule the wakeup
+    assert(m_consumer != NULL);
+    m_consumer->scheduleEventAbsolute(arrival_time);
+    m_consumer->storeEventInfo(m_vnet_id);
+}
+
+Cycles
+MessageBuffer::dequeue()
+{
+    DPRINTF(RubyQueue, "Popping\n");
+    assert(isReady());
+
+    // get MsgPtr of the message about to be dequeued
+    MsgPtr message = m_prio_heap.front().m_msgptr;
+
+    // get the delay cycles
+    message->updateDelayedTicks(m_receiver->clockEdge());
+    Cycles delayCycles =
+        m_receiver->ticksToCycles(message->getDelayedTicks());
+
+    // record previous size and time so the current buffer size isn't
+    // adjusted until next cycle
+    if (m_time_last_time_pop < m_receiver->clockEdge()) {
+        m_size_at_cycle_start = m_prio_heap.size();
+        m_time_last_time_pop = m_receiver->clockEdge();
+    }
+
+    pop_heap(m_prio_heap.begin(), m_prio_heap.end(),
+        greater<MessageBufferNode>());
+    m_prio_heap.pop_back();
+
+    return delayCycles;
+}
+
+void
+MessageBuffer::clear()
+{
+    m_prio_heap.clear();
+
+    m_msg_counter = 0;
+    m_time_last_time_enqueue = Cycles(0);
+    m_time_last_time_pop = 0;
+    m_size_at_cycle_start = 0;
+    m_msgs_this_cycle = 0;
+}
+
+void
+MessageBuffer::recycle()
+{
+    DPRINTF(RubyQueue, "Recycling.\n");
+    assert(isReady());
+    MessageBufferNode node = m_prio_heap.front();
+    pop_heap(m_prio_heap.begin(), m_prio_heap.end(),
+        greater<MessageBufferNode>());
+
+    node.m_time = m_receiver->clockEdge(m_recycle_latency);
+    m_prio_heap.back() = node;
+    push_heap(m_prio_heap.begin(), m_prio_heap.end(),
+        greater<MessageBufferNode>());
+    m_consumer->
+        scheduleEventAbsolute(m_receiver->clockEdge(m_recycle_latency));
+}
+
+void
+MessageBuffer::reanalyzeList(list<MsgPtr> &lt, Tick nextTick)
+{
+    while(!lt.empty()) {
+        m_msg_counter++;
+        MessageBufferNode msgNode(nextTick, m_msg_counter, lt.front());
+
+        m_prio_heap.push_back(msgNode);
+        push_heap(m_prio_heap.begin(), m_prio_heap.end(),
+                  greater<MessageBufferNode>());
+
+        m_consumer->scheduleEventAbsolute(nextTick);
+        lt.pop_front();
+    }
+}
+
+void
+MessageBuffer::reanalyzeMessages(const Address& addr)
+{
+    DPRINTF(RubyQueue, "ReanalyzeMessages\n");
+    assert(m_stall_msg_map.count(addr) > 0);
+    Tick nextTick = m_receiver->clockEdge(Cycles(1));
+
+    //
+    // Put all stalled messages associated with this address back on the
+    // prio heap
+    //
+    reanalyzeList(m_stall_msg_map[addr], nextTick);
+    m_stall_msg_map.erase(addr);
+}
+
+void
+MessageBuffer::reanalyzeAllMessages()
+{
+    DPRINTF(RubyQueue, "ReanalyzeAllMessages\n");
+    Tick nextTick = m_receiver->clockEdge(Cycles(1));
+
+    //
+    // Put all stalled messages associated with this address back on the
+    // prio heap
+    //
+    for (StallMsgMapType::iterator map_iter = m_stall_msg_map.begin();
+         map_iter != m_stall_msg_map.end(); ++map_iter) {
+        reanalyzeList(map_iter->second, nextTick);
+    }
+    m_stall_msg_map.clear();
+}
+
+void
+MessageBuffer::stallMessage(const Address& addr)
+{
+    DPRINTF(RubyQueue, "Stalling due to %s\n", addr);
+    assert(isReady());
+    assert(addr.getOffset() == 0);
+    MsgPtr message = m_prio_heap.front().m_msgptr;
+
+    dequeue();
+
+    //
+    // Note: no event is scheduled to analyze the map at a later time.
+    // Instead the controller is responsible to call reanalyzeMessages when
+    // these addresses change state.
+    //
+    (m_stall_msg_map[addr]).push_back(message);
+}
+
+void
+MessageBuffer::print(ostream& out) const
+{
+    ccprintf(out, "[MessageBuffer: ");
+    if (m_consumer != NULL) {
+        ccprintf(out, " consumer-yes ");
+    }
+
+    vector<MessageBufferNode> copy(m_prio_heap);
+    sort_heap(copy.begin(), copy.end(), greater<MessageBufferNode>());
+    ccprintf(out, "%s] %s", copy, m_name);
+}
+
+bool
+MessageBuffer::isReady() const
+{
+    return ((m_prio_heap.size() > 0) &&
+            (m_prio_heap.front().m_time <= m_receiver->clockEdge()));
+}
+
+bool
+MessageBuffer::functionalRead(Packet *pkt)
+{
+    // Check the priority heap and read any messages that may
+    // correspond to the address in the packet.
+    for (unsigned int i = 0; i < m_prio_heap.size(); ++i) {
+        Message *msg = m_prio_heap[i].m_msgptr.get();
+        if (msg->functionalRead(pkt)) return true;
+    }
+
+    // Read the messages in the stall queue that correspond
+    // to the address in the packet.
+    for (StallMsgMapType::iterator map_iter = m_stall_msg_map.begin();
+         map_iter != m_stall_msg_map.end();
+         ++map_iter) {
+
+        for (std::list<MsgPtr>::iterator it = (map_iter->second).begin();
+            it != (map_iter->second).end(); ++it) {
+
+            Message *msg = (*it).get();
+            if (msg->functionalRead(pkt)) return true;
+        }
+    }
+    return false;
+}
+
+uint32_t
+MessageBuffer::functionalWrite(Packet *pkt)
+{
+    uint32_t num_functional_writes = 0;
+
+    // Check the priority heap and write any messages that may
+    // correspond to the address in the packet.
+    for (unsigned int i = 0; i < m_prio_heap.size(); ++i) {
+        Message *msg = m_prio_heap[i].m_msgptr.get();
+        if (msg->functionalWrite(pkt)) {
+            num_functional_writes++;
+        }
+    }
+
+    // Check the stall queue and write any messages that may
+    // correspond to the address in the packet.
+    for (StallMsgMapType::iterator map_iter = m_stall_msg_map.begin();
+         map_iter != m_stall_msg_map.end();
+         ++map_iter) {
+
+        for (std::list<MsgPtr>::iterator it = (map_iter->second).begin();
+            it != (map_iter->second).end(); ++it) {
+
+            Message *msg = (*it).get();
+            if (msg->functionalWrite(pkt)) {
+                num_functional_writes++;
+            }
+        }
+    }
+
+    return num_functional_writes;
+}
diff --git a/src/mem/ruby/network/MessageBuffer.hh b/src/mem/ruby/network/MessageBuffer.hh
new file mode 100644
index 000000000..6d51eade9
--- /dev/null
+++ b/src/mem/ruby/network/MessageBuffer.hh
@@ -0,0 +1,215 @@
+/*
+ * 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/ruby/common/Address.hh"
+#include "mem/ruby/common/Consumer.hh"
+#include "mem/ruby/network/MessageBufferNode.hh"
+#include "mem/ruby/slicc_interface/Message.hh"
+#include "mem/packet.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(unsigned 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; }
+
+    //! Function for extracting the message at the head of the
+    //! message queue.  The function assumes that the queue is nonempty.
+    const Message* peek() const;
+
+    const MsgPtr&
+    peekMsgPtr() const
+    {
+        assert(isReady());
+        return m_prio_heap.front().m_msgptr;
+    }
+
+    void enqueue(MsgPtr message) { enqueue(message, Cycles(1)); }
+    void enqueue(MsgPtr message, Cycles delta);
+
+    //! Updates the delay cycles of the message at the head of the queue,
+    //! removes it from the queue and returns its total delay.
+    Cycles dequeue();
+
+    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(unsigned int size) { m_max_size = size; }
+    unsigned int getSize();
+    void setRandomization(bool random_flag) { m_randomization = random_flag; }
+
+    void clear();
+    void print(std::ostream& out) const;
+    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:
+    void reanalyzeList(std::list<MsgPtr> &, Tick);
+
+  private:
+    //added by SS
+    Cycles m_recycle_latency;
+
+    // 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;
+
+    StallMsgMapType m_stall_msg_map;
+    std::string m_name;
+
+    unsigned int m_max_size;
+    Cycles m_time_last_time_size_checked;
+    unsigned 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;
+    Tick m_time_last_time_pop;
+    Tick m_last_arrival_time;
+
+    unsigned int m_size_at_cycle_start;
+    unsigned 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;
+
+    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__
diff --git a/src/mem/ruby/network/MessageBufferNode.cc b/src/mem/ruby/network/MessageBufferNode.cc
new file mode 100644
index 000000000..2e682b096
--- /dev/null
+++ b/src/mem/ruby/network/MessageBufferNode.cc
@@ -0,0 +1,39 @@
+/*
+ * 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.
+ */
+
+#include "mem/ruby/network/MessageBufferNode.hh"
+
+void
+MessageBufferNode::print(std::ostream& out) const
+{
+    out << "[";
+    out << m_time << ", ";
+    out << m_msg_counter << ", ";
+    out << *m_msgptr << "; ";
+    out << "]";
+}
diff --git a/src/mem/ruby/network/MessageBufferNode.hh b/src/mem/ruby/network/MessageBufferNode.hh
new file mode 100644
index 000000000..16aec8a1b
--- /dev/null
+++ b/src/mem/ruby/network/MessageBufferNode.hh
@@ -0,0 +1,75 @@
+/*
+ * 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.
+ */
+
+#ifndef __MEM_RUBY_BUFFERS_MESSAGEBUFFERNODE_HH__
+#define __MEM_RUBY_BUFFERS_MESSAGEBUFFERNODE_HH__
+
+#include <iostream>
+
+#include "mem/ruby/slicc_interface/Message.hh"
+
+class MessageBufferNode
+{
+  public:
+    MessageBufferNode()
+        : m_time(0), m_msg_counter(0)
+    {}
+
+    MessageBufferNode(const Tick time, uint64_t counter,
+                      const MsgPtr& msgptr)
+        : m_time(time), m_msg_counter(counter), m_msgptr(msgptr)
+    {}
+
+    void print(std::ostream& out) const;
+
+  public:
+    Tick m_time;
+    uint64_t m_msg_counter; // FIXME, should this be a 64-bit value?
+    MsgPtr m_msgptr;
+};
+
+inline bool
+operator>(const MessageBufferNode& n1, const MessageBufferNode& n2)
+{
+    if (n1.m_time == n2.m_time) {
+        assert(n1.m_msg_counter != n2.m_msg_counter);
+        return n1.m_msg_counter > n2.m_msg_counter;
+    } else {
+        return n1.m_time > n2.m_time;
+    }
+}
+
+inline std::ostream&
+operator<<(std::ostream& out, const MessageBufferNode& obj)
+{
+    obj.print(out);
+    out << std::flush;
+    return out;
+}
+
+#endif // __MEM_RUBY_BUFFERS_MESSAGEBUFFERNODE_HH__
diff --git a/src/mem/ruby/network/SConscript b/src/mem/ruby/network/SConscript
index c4abba716..1b0b1c94b 100644
--- a/src/mem/ruby/network/SConscript
+++ b/src/mem/ruby/network/SConscript
@@ -39,5 +39,7 @@ SimObject('Network.py')
 
 Source('BasicLink.cc')
 Source('BasicRouter.cc')
+Source('MessageBuffer.cc')
+Source('MessageBufferNode.cc')
 Source('Network.cc')
 Source('Topology.cc')
diff --git a/src/mem/ruby/network/garnet/BaseGarnetNetwork.cc b/src/mem/ruby/network/garnet/BaseGarnetNetwork.cc
index f237c4dcc..01f1b80ed 100644
--- a/src/mem/ruby/network/garnet/BaseGarnetNetwork.cc
+++ b/src/mem/ruby/network/garnet/BaseGarnetNetwork.cc
@@ -28,8 +28,8 @@
  * Authors: Niket Agarwal
  */
 
-#include "mem/ruby/buffers/MessageBuffer.hh"
 #include "mem/ruby/network/garnet/BaseGarnetNetwork.hh"
+#include "mem/ruby/network/MessageBuffer.hh"
 
 using namespace std;
 
diff --git a/src/mem/ruby/network/garnet/fixed-pipeline/NetworkInterface_d.cc b/src/mem/ruby/network/garnet/fixed-pipeline/NetworkInterface_d.cc
index 3e4088038..5f9493806 100644
--- a/src/mem/ruby/network/garnet/fixed-pipeline/NetworkInterface_d.cc
+++ b/src/mem/ruby/network/garnet/fixed-pipeline/NetworkInterface_d.cc
@@ -34,7 +34,7 @@
 #include "base/cast.hh"
 #include "base/stl_helpers.hh"
 #include "debug/RubyNetwork.hh"
-#include "mem/ruby/buffers/MessageBuffer.hh"
+#include "mem/ruby/network/MessageBuffer.hh"
 #include "mem/ruby/network/garnet/fixed-pipeline/NetworkInterface_d.hh"
 #include "mem/ruby/network/garnet/fixed-pipeline/flitBuffer_d.hh"
 #include "mem/ruby/slicc_interface/NetworkMessage.hh"
diff --git a/src/mem/ruby/network/garnet/flexible-pipeline/NetworkInterface.cc b/src/mem/ruby/network/garnet/flexible-pipeline/NetworkInterface.cc
index ba32abd44..13bbe2b08 100644
--- a/src/mem/ruby/network/garnet/flexible-pipeline/NetworkInterface.cc
+++ b/src/mem/ruby/network/garnet/flexible-pipeline/NetworkInterface.cc
@@ -34,7 +34,7 @@
 #include "base/cast.hh"
 #include "base/stl_helpers.hh"
 #include "debug/RubyNetwork.hh"
-#include "mem/ruby/buffers/MessageBuffer.hh"
+#include "mem/ruby/network/MessageBuffer.hh"
 #include "mem/ruby/network/garnet/flexible-pipeline/NetworkInterface.hh"
 #include "mem/ruby/network/garnet/flexible-pipeline/flitBuffer.hh"
 #include "mem/ruby/slicc_interface/NetworkMessage.hh"
diff --git a/src/mem/ruby/network/simple/PerfectSwitch.cc b/src/mem/ruby/network/simple/PerfectSwitch.cc
index cf2430e36..0c6111c48 100644
--- a/src/mem/ruby/network/simple/PerfectSwitch.cc
+++ b/src/mem/ruby/network/simple/PerfectSwitch.cc
@@ -30,7 +30,7 @@
 
 #include "base/cast.hh"
 #include "debug/RubyNetwork.hh"
-#include "mem/ruby/buffers/MessageBuffer.hh"
+#include "mem/ruby/network/MessageBuffer.hh"
 #include "mem/ruby/network/simple/PerfectSwitch.hh"
 #include "mem/ruby/network/simple/SimpleNetwork.hh"
 #include "mem/ruby/network/simple/Switch.hh"
diff --git a/src/mem/ruby/network/simple/SimpleNetwork.cc b/src/mem/ruby/network/simple/SimpleNetwork.cc
index 05b729183..9eca157f6 100644
--- a/src/mem/ruby/network/simple/SimpleNetwork.cc
+++ b/src/mem/ruby/network/simple/SimpleNetwork.cc
@@ -31,8 +31,8 @@
 
 #include "base/cast.hh"
 #include "base/stl_helpers.hh"
-#include "mem/ruby/buffers/MessageBuffer.hh"
 #include "mem/ruby/common/NetDest.hh"
+#include "mem/ruby/network/MessageBuffer.hh"
 #include "mem/ruby/network/simple/SimpleLink.hh"
 #include "mem/ruby/network/simple/SimpleNetwork.hh"
 #include "mem/ruby/network/simple/Switch.hh"
diff --git a/src/mem/ruby/network/simple/Switch.cc b/src/mem/ruby/network/simple/Switch.cc
index 1e153be76..6e116d82c 100644
--- a/src/mem/ruby/network/simple/Switch.cc
+++ b/src/mem/ruby/network/simple/Switch.cc
@@ -30,7 +30,7 @@
 
 #include "base/cast.hh"
 #include "base/stl_helpers.hh"
-#include "mem/ruby/buffers/MessageBuffer.hh"
+#include "mem/ruby/network/MessageBuffer.hh"
 #include "mem/ruby/network/simple/PerfectSwitch.hh"
 #include "mem/ruby/network/simple/SimpleNetwork.hh"
 #include "mem/ruby/network/simple/Switch.hh"
diff --git a/src/mem/ruby/network/simple/Throttle.cc b/src/mem/ruby/network/simple/Throttle.cc
index da7b1732b..40958a6da 100644
--- a/src/mem/ruby/network/simple/Throttle.cc
+++ b/src/mem/ruby/network/simple/Throttle.cc
@@ -31,8 +31,8 @@
 #include "base/cast.hh"
 #include "base/cprintf.hh"
 #include "debug/RubyNetwork.hh"
-#include "mem/ruby/buffers/MessageBuffer.hh"
 #include "mem/ruby/network/simple/Throttle.hh"
+#include "mem/ruby/network/MessageBuffer.hh"
 #include "mem/ruby/network/Network.hh"
 #include "mem/ruby/slicc_interface/NetworkMessage.hh"
 #include "mem/ruby/system/System.hh"