MessageBuffer.hh

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/*
 * Copyright (c) 2019-2021 ARM Limited
 * All rights reserved.
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * 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
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 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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/*
 * Unordered buffer of messages that can be inserted such
 * that they can be dequeued after a given delta time has expired.
 */
 
#ifndef __MEM_RUBY_NETWORK_MESSAGEBUFFER_HH__
#define __MEM_RUBY_NETWORK_MESSAGEBUFFER_HH__
 
#include <algorithm>
#include <cassert>
#include <functional>
#include <iostream>
#include <string>
#include <unordered_map>
#include <vector>
 
#include "base/trace.hh"
#include "debug/RubyQueue.hh"
#include "mem/packet.hh"
#include "mem/port.hh"
#include "mem/ruby/common/Address.hh"
#include "mem/ruby/common/Consumer.hh"
#include "mem/ruby/network/dummy_port.hh"
#include "mem/ruby/slicc_interface/Message.hh"
#include "params/MessageBuffer.hh"
#include "sim/sim_object.hh"
 
namespace gem5
{
 
namespace ruby
{
 
class MessageBuffer : public SimObject
{
  public:
    typedef MessageBufferParams Params;
    MessageBuffer(const Params &p);
 
    void reanalyzeMessages(Addr addr, Tick current_time);
    void reanalyzeAllMessages(Tick current_time);
    void stallMessage(Addr addr, Tick current_time);
    // return true if the stall map has a message of this address
    bool hasStalledMsg(Addr addr) const;
 
    // TRUE if head of queue timestamp <= SystemTime
    bool isReady(Tick current_time) const;
 
    // earliest tick the head of queue will be ready, or MaxTick if empty
    Tick readyTime() const;
 
    void
    delayHead(Tick current_time, Tick delta)
    {
        MsgPtr m = m_prio_heap.front();
        std::pop_heap(m_prio_heap.begin(), m_prio_heap.end(),
                      std::greater<MsgPtr>());
        m_prio_heap.pop_back();
        enqueue(m, current_time, delta);
    }
 
    bool areNSlotsAvailable(unsigned int n, Tick curTime);
    int getPriority() { return m_priority_rank; }
    void setPriority(int rank) { m_priority_rank = rank; }
    void setConsumer(Consumer* consumer)
    {
        DPRINTF(RubyQueue, "Setting consumer: %s\n", *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;
    }
 
    Consumer* getConsumer() { return m_consumer; }
 
    bool getOrdered() { return m_strict_fifo; }
 
    const Message* peek() const;
 
    const MsgPtr &peekMsgPtr() const { return m_prio_heap.front(); }
 
    void enqueue(MsgPtr message, Tick curTime, Tick delta,
                bool bypassStrictFIFO = false);
 
    // Defer enqueueing a message to a later cycle by putting it aside and not
    // enqueueing it in this cycle
    // The corresponding controller will need to explicitly enqueue the
    // deferred message into the message buffer. Otherwise, the message will
    // be lost.
    void deferEnqueueingMessage(Addr addr, MsgPtr message);
 
    // enqueue all previously deferred messages that are associated with the
    // input address
    void enqueueDeferredMessages(Addr addr, Tick curTime, Tick delay);
    bool isDeferredMsgMapEmpty(Addr addr) const;
 
    Tick dequeue(Tick current_time, bool decrement_messages = true);
 
    void registerDequeueCallback(std::function<void()> callback);
    void unregisterDequeueCallback();
 
    void recycle(Tick current_time, Tick recycle_latency);
    bool isEmpty() const { return m_prio_heap.size() == 0; }
    bool isStallMapEmpty() { return m_stall_msg_map.size() == 0; }
    unsigned int getStallMapSize() { return m_stall_msg_map.size(); }
 
    unsigned int getSize(Tick curTime);
 
    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; }
 
    int getIncomingLink() const { return m_input_link_id; }
    int getVnet() const { return m_vnet_id; }
 
    Port &
    getPort(const std::string &, PortID idx=InvalidPortID) override
    {
        return RubyDummyPort::instance();
    }
 
    // 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.
    uint32_t functionalWrite(Packet *pkt)
    {
        return functionalAccess(pkt, false, nullptr);
    }
 
    // Function for figuring if message in the buffer has valid data for
    // the packet.
    // Returns true only if a message was found with valid data and the
    // read was performed.
    bool functionalRead(Packet *pkt)
    {
        return functionalAccess(pkt, true, nullptr) == 1;
    }
 
    // Functional read with mask
    bool functionalRead(Packet *pkt, WriteMask &mask)
    {
        return functionalAccess(pkt, true, &mask) == 1;
    }
 
    int routingPriority() const { return m_routing_priority; }
 
  private:
    void reanalyzeList(std::list<MsgPtr> &, Tick);
 
    uint32_t functionalAccess(Packet *pkt, bool is_read, WriteMask *mask);
 
  private:
    // Data Members (m_ prefix)
    Consumer* m_consumer;
    std::vector<MsgPtr> m_prio_heap;
 
    std::function<void()> m_dequeue_callback;
 
    // use a std::map for the stalled messages as this container is
    // sorted and ensures a well-defined iteration order
    typedef std::map<Addr, std::list<MsgPtr> > StallMsgMapType;
 
    StallMsgMapType m_stall_msg_map;
 
    typedef std::unordered_map<Addr, std::vector<MsgPtr>> DeferredMsgMapType;
    DeferredMsgMapType m_deferred_msg_map;
 
    int m_stall_map_size;
 
    const unsigned int m_max_size;
 
    const unsigned int m_max_dequeue_rate;
 
    unsigned int m_dequeues_this_cy;
 
    Tick m_time_last_time_size_checked;
    unsigned int m_size_last_time_size_checked;
 
    // variables used so enqueues appear to happen immediately, while
    // pop happen the next cycle
    Tick 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_stalled_at_cycle_start;
    unsigned int m_msgs_this_cycle;
 
    uint64_t m_msg_counter;
    int m_priority_rank;
 
    bool m_last_message_strict_fifo_bypassed;
 
    const bool m_strict_fifo;
    const MessageRandomization m_randomization;
    const bool m_allow_zero_latency;
 
    const int m_routing_priority;
 
    int m_input_link_id;
    int m_vnet_id;
 
    // Count the # of times I didn't have N slots available
    statistics::Scalar m_not_avail_count;
    statistics::Scalar m_msg_count;
    statistics::Average m_buf_msgs;
    statistics::Scalar m_stall_time;
    statistics::Scalar m_stall_count;
    statistics::Formula m_avg_stall_time;
    statistics::Formula m_occupancy;
};
 
Tick random_time();
 
inline std::ostream&
operator<<(std::ostream& out, const MessageBuffer& obj)
{
    obj.print(out);
    out << std::flush;
    return out;
}
 
} // namespace ruby
} // namespace gem5
 
#endif //__MEM_RUBY_NETWORK_MESSAGEBUFFER_HH__