Ruby: Add new object called WireBuffer to mimic a Wire.

This is a substitute for MessageBuffers between controllers where you don't
want messages to actually go through the Network, because requests/responses can
always get reordered wrt to one another (even if you turn off Randomization and turn on Ordered)
because you are, after all, going through a network with contention. For systems where you model
multiple controllers that are very tightly coupled and do not actually go through a network,
it is a pain to have to write a coherence protocol to account for mixed up request/response orderings
despite the fact that it's completely unrealistic.  This is *not* meant as a substitute for real
MessageBuffers when messages do in fact go over a network.

4 files changed, 316 insertions, 0 deletions

diff --git a/src/mem/ruby/system/SConscript b/src/mem/ruby/system/SConscript
index edc9d451f..f1e7c425c 100644
--- a/src/mem/ruby/system/SConscript
+++ b/src/mem/ruby/system/SConscript
@@ -37,6 +37,7 @@ SimObject('Cache.py')
 SimObject('Sequencer.py')
 SimObject('DirectoryMemory.py')
 SimObject('MemoryControl.py')
+SimObject('WireBuffer.py')
 SimObject('RubySystem.py')
 
 Source('DMASequencer.cc')
@@ -44,6 +45,7 @@ Source('DirectoryMemory.cc')
 Source('SparseMemory.cc')
 Source('CacheMemory.cc')
 Source('MemoryControl.cc')
+Source('WireBuffer.cc')
 Source('MemoryNode.cc')
 Source('PersistentTable.cc')
 Source('RubyPort.cc')
diff --git a/src/mem/ruby/system/WireBuffer.cc b/src/mem/ruby/system/WireBuffer.cc
new file mode 100644
index 000000000..bab935c5d
--- /dev/null
+++ b/src/mem/ruby/system/WireBuffer.cc
@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2010 Advanced Micro Devices, Inc.
+ * 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.
+ *
+ * Author:  Lisa Hsu
+ *
+ */
+
+#include <algorithm>
+#include <functional>
+
+#include "base/cprintf.hh"
+#include "base/stl_helpers.hh"
+#include "mem/ruby/system/WireBuffer.hh"
+
+using namespace std;
+
+class Consumer;
+
+
+// Output operator definition
+
+ostream&
+operator<<(ostream& out, const WireBuffer& obj)
+{
+    obj.print(out);
+    out << flush;
+    return out;
+}
+
+
+// ****************************************************************
+
+// CONSTRUCTOR
+WireBuffer::WireBuffer(const Params *p)
+    : SimObject(p)
+{
+    m_msg_counter = 0;
+}
+
+void
+WireBuffer::init()
+{
+}
+
+WireBuffer::~WireBuffer()
+{
+}
+
+void
+WireBuffer::enqueue(MsgPtr message, int latency)
+{
+    m_msg_counter++;
+    Time current_time = g_eventQueue_ptr->getTime();
+    Time arrival_time = current_time + latency;
+    assert(arrival_time > current_time);
+    MessageBufferNode thisNode(arrival_time, m_msg_counter, message);
+    m_message_queue.push_back(thisNode);
+    if (m_consumer_ptr != NULL) {
+        g_eventQueue_ptr->scheduleEventAbsolute(m_consumer_ptr, arrival_time);
+    } else {
+        panic("No Consumer for WireBuffer! %s\n", *this);
+    }
+}
+
+void
+WireBuffer::dequeue()
+{
+    assert(isReady());
+    pop_heap(m_message_queue.begin(), m_message_queue.end(),
+        greater<MessageBufferNode>());
+    m_message_queue.pop_back();
+}
+
+const Message*
+WireBuffer::peek()
+{
+    MessageBufferNode node = peekNode();
+    Message* msg_ptr = node.m_msgptr.get();
+    assert(msg_ptr != NULL);
+    return msg_ptr;
+}
+
+MessageBufferNode
+WireBuffer::peekNode()
+{
+    assert(isReady());
+    MessageBufferNode req = m_message_queue.front();
+    return req;
+}
+
+void
+WireBuffer::recycle()
+{
+    // Because you don't want anything reordered, make sure the recycle latency
+    // is just 1 cycle. As a result, you really want to use this only in
+    // Wire-like situations because you don't want to deadlock as a result of
+    // being stuck behind something if you're not actually supposed to.
+    assert(isReady());
+    MessageBufferNode node = m_message_queue.front();
+    pop_heap(m_message_queue.begin(), m_message_queue.end(),
+        greater<MessageBufferNode>());
+    node.m_time = g_eventQueue_ptr->getTime() + 1;
+    m_message_queue.back() = node;
+    push_heap(m_message_queue.begin(), m_message_queue.end(),
+        greater<MessageBufferNode>());
+    g_eventQueue_ptr->scheduleEventAbsolute(m_consumer_ptr,
+        g_eventQueue_ptr->getTime() + 1);
+}
+
+bool
+WireBuffer::isReady()
+{
+    return ((!m_message_queue.empty()) &&
+            (m_message_queue.front().m_time <= g_eventQueue_ptr->getTime()));
+}
+
+void
+WireBuffer::print(ostream& out) const
+{
+}
+
+void
+WireBuffer::printConfig(ostream& out)
+{
+}
+
+void
+WireBuffer::clearStats() const
+{
+}
+
+void
+WireBuffer::printStats(ostream& out) const
+{
+}
+
+void
+WireBuffer::wakeup()
+{
+}
+
+WireBuffer *
+RubyWireBufferParams::create()
+{
+    return new WireBuffer(this);
+}
+
diff --git a/src/mem/ruby/system/WireBuffer.hh b/src/mem/ruby/system/WireBuffer.hh
new file mode 100644
index 000000000..1404f5561
--- /dev/null
+++ b/src/mem/ruby/system/WireBuffer.hh
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2010 Advanced Micro Devices, Inc.
+ * 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.
+ *
+ * Author: Lisa Hsu
+ *
+ */
+
+#ifndef __MEM_RUBY_SYSTEM_WIREBUFFER_HH__
+#define __MEM_RUBY_SYSTEM_WIREBUFFER_HH__
+
+#include <iostream>
+#include <vector>
+#include <string>
+
+#include "mem/ruby/buffers/MessageBufferNode.hh"
+#include "mem/ruby/common/Global.hh"
+#include "mem/ruby/eventqueue/RubyEventQueue.hh"
+#include "params/RubyWireBuffer.hh"
+#include "sim/sim_object.hh"
+
+
+//////////////////////////////////////////////////////////////////////////////
+// This object was written to literally mimic a Wire in Ruby, in the sense
+// that there is no way for messages to get reordered en route on the WireBuffer.
+// With Message Buffers, even if randomization is off and ordered is on,
+// messages can arrive in different orders than they were sent because of
+// network issues. This mimics a Wire, such that that is not possible. This can
+// allow for messages between closely coupled controllers that are not actually
+// separated by a network in real systems to simplify coherence.
+/////////////////////////////////////////////////////////////////////////////
+
+class Consumer;
+class Message;  // I added this and removed Message.hh
+
+class WireBuffer : public SimObject
+{
+  public:
+    typedef RubyWireBufferParams Params;
+    WireBuffer(const Params *p);
+    void init();
+
+    ~WireBuffer();
+
+    void wakeup();
+
+    void setConsumer(Consumer* consumer_ptr)
+    {
+        m_consumer_ptr = consumer_ptr;
+    }
+    Consumer* getConsumer() { return m_consumer_ptr; };
+    void setDescription(const std::string& name) { m_description = name; };
+    std::string getDescription() { return m_description; };
+
+    void enqueue(MsgPtr message, int latency );
+    void dequeue();
+    const Message* peek();
+    MessageBufferNode peekNode();
+    void recycle();
+    bool isReady();
+    bool areNSlotsAvailable(int n) { return true; };  // infinite queue length
+
+    void printConfig(std::ostream& out);
+    void print(std::ostream& out) const;
+    void clearStats() const;
+    void printStats(std::ostream& out) const;
+
+//    int m_dummy;
+    uint64_t m_msg_counter;
+
+  private:
+    // Private copy constructor and assignment operator
+    WireBuffer (const WireBuffer& obj);
+    WireBuffer& operator=(const WireBuffer& obj);
+
+    // data members
+    Consumer* m_consumer_ptr;  // Consumer to signal a wakeup()
+    std::string m_description;
+
+    // queues where memory requests live
+    std::vector<MessageBufferNode> m_message_queue;
+
+};
+
+#endif // __MEM_RUBY_SYSTEM_WireBuffer_HH__
diff --git a/src/mem/ruby/system/WireBuffer.py b/src/mem/ruby/system/WireBuffer.py
new file mode 100644
index 000000000..0bcc291bb
--- /dev/null
+++ b/src/mem/ruby/system/WireBuffer.py
@@ -0,0 +1,35 @@
+# Copyright (c) 2010 Advanced Micro Devices, Inc.
+# 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.
+#
+# Author: Lisa Hsu
+
+from m5.params import *
+from m5.SimObject import SimObject
+#from Controller import RubyController
+
+class RubyWireBuffer(SimObject):
+    type = 'RubyWireBuffer'
+    cxx_class = 'WireBuffer'