src/mem/ruby/network/MessageBuffer.hh

   1 /*
   2  * Copyright (c) 2019,2020 ARM Limited
   3  * All rights reserved.
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
  15  * All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions are
  19  * met: redistributions of source code must retain the above copyright
  20  * notice, this list of conditions and the following disclaimer;
  21  * redistributions in binary form must reproduce the above copyright
  22  * notice, this list of conditions and the following disclaimer in the
  23  * documentation and/or other materials provided with the distribution;
  24  * neither the name of the copyright holders nor the names of its
  25  * contributors may be used to endorse or promote products derived from
  26  * this software without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  31  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  32  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  34  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 /*
  42  * Unordered buffer of messages that can be inserted such
  43  * that they can be dequeued after a given delta time has expired.
  44  */
  45
  46 #ifndef __MEM_RUBY_NETWORK_MESSAGEBUFFER_HH__
  47 #define __MEM_RUBY_NETWORK_MESSAGEBUFFER_HH__
  48
  49 #include <algorithm>
  50 #include <cassert>
  51 #include <functional>
  52 #include <iostream>
  53 #include <string>
  54 #include <unordered_map>
  55 #include <vector>
  56
  57 #include "base/trace.hh"
  58 #include "debug/RubyQueue.hh"
  59 #include "mem/packet.hh"
  60 #include "mem/port.hh"
  61 #include "mem/ruby/common/Address.hh"
  62 #include "mem/ruby/common/Consumer.hh"
  63 #include "mem/ruby/network/dummy_port.hh"
  64 #include "mem/ruby/slicc_interface/Message.hh"
  65 #include "params/MessageBuffer.hh"
  66 #include "sim/sim_object.hh"
  67
  68 class MessageBuffer : public SimObject
  69 {
  70   public:
  71     typedef MessageBufferParams Params;
  72     MessageBuffer(const Params &p);
  73
  74     void reanalyzeMessages(Addr addr, Tick current_time);
  75     void reanalyzeAllMessages(Tick current_time);
  76     void stallMessage(Addr addr, Tick current_time);
  77     // return true if the stall map has a message of this address
  78     bool hasStalledMsg(Addr addr) const;
  79
  80     // TRUE if head of queue timestamp <= SystemTime
  81     bool isReady(Tick current_time) const;
  82
  83     void
  84     delayHead(Tick current_time, Tick delta)
  85     {
  86         MsgPtr m = m_prio_heap.front();
  87         std::pop_heap(m_prio_heap.begin(), m_prio_heap.end(),
  88                       std::greater<MsgPtr>());
  89         m_prio_heap.pop_back();
  90         enqueue(m, current_time, delta);
  91     }
  92
  93     bool areNSlotsAvailable(unsigned int n, Tick curTime);
  94     int getPriority() { return m_priority_rank; }
  95     void setPriority(int rank) { m_priority_rank = rank; }
  96     void setConsumer(Consumer* consumer)
  97     {
  98         DPRINTF(RubyQueue, "Setting consumer: %s\n", *consumer);
  99         if (m_consumer != NULL) {
 100             fatal("Trying to connect %s to MessageBuffer %s. \
 101                   \n%s already connected. Check the cntrl_id's.\n",
 102                   *consumer, *this, *m_consumer);
 103         }
 104         m_consumer = consumer;
 105     }
 106
 107     Consumer* getConsumer() { return m_consumer; }
 108
 109     bool getOrdered() { return m_strict_fifo; }
 110
 111     //! Function for extracting the message at the head of the
 112     //! message queue.  The function assumes that the queue is nonempty.
 113     const Message* peek() const;
 114
 115     const MsgPtr &peekMsgPtr() const { return m_prio_heap.front(); }
 116
 117     void enqueue(MsgPtr message, Tick curTime, Tick delta);
 118
 119     // Defer enqueueing a message to a later cycle by putting it aside and not
 120     // enqueueing it in this cycle
 121     // The corresponding controller will need to explicitly enqueue the
 122     // deferred message into the message buffer. Otherwise, the message will
 123     // be lost.
 124     void deferEnqueueingMessage(Addr addr, MsgPtr message);
 125
 126     // enqueue all previously deferred messages that are associated with the
 127     // input address
 128     void enqueueDeferredMessages(Addr addr, Tick curTime, Tick delay);
 129     bool isDeferredMsgMapEmpty(Addr addr) const;
 130
 131     //! Updates the delay cycles of the message at the head of the queue,
 132     //! removes it from the queue and returns its total delay.
 133     Tick dequeue(Tick current_time, bool decrement_messages = true);
 134
 135     void registerDequeueCallback(std::function<void()> callback);
 136     void unregisterDequeueCallback();
 137
 138     void recycle(Tick current_time, Tick recycle_latency);
 139     bool isEmpty() const { return m_prio_heap.size() == 0; }
 140     bool isStallMapEmpty() { return m_stall_msg_map.size() == 0; }
 141     unsigned int getStallMapSize() { return m_stall_msg_map.size(); }
 142
 143     unsigned int getSize(Tick curTime);
 144
 145     void clear();
 146     void print(std::ostream& out) const;
 147     void clearStats() { m_not_avail_count = 0; m_msg_counter = 0; }
 148
 149     void setIncomingLink(int link_id) { m_input_link_id = link_id; }
 150     void setVnet(int net) { m_vnet_id = net; }
 151
 152     Port &
 153     getPort(const std::string &, PortID idx=InvalidPortID) override
 154     {
 155         return RubyDummyPort::instance();
 156     }
 157
 158     // Function for figuring out if any of the messages in the buffer need
 159     // to be updated with the data from the packet.
 160     // Return value indicates the number of messages that were updated.
 161     uint32_t functionalWrite(Packet *pkt)
 162     {
 163         return functionalAccess(pkt, false);
 164     }
 165
 166     // Function for figuring if message in the buffer has valid data for
 167     // the packet.
 168     // Returns true only if a message was found with valid data and the
 169     // read was performed.
 170     bool functionalRead(Packet *pkt)
 171     {
 172         return functionalAccess(pkt, true) == 1;
 173     }
 174
 175   private:
 176     void reanalyzeList(std::list<MsgPtr> &, Tick);
 177
 178     uint32_t functionalAccess(Packet *pkt, bool is_read);
 179
 180   private:
 181     // Data Members (m_ prefix)
 182     //! Consumer to signal a wakeup(), can be NULL
 183     Consumer* m_consumer;
 184     std::vector<MsgPtr> m_prio_heap;
 185
 186     std::function<void()> m_dequeue_callback;
 187
 188     // use a std::map for the stalled messages as this container is
 189     // sorted and ensures a well-defined iteration order
 190     typedef std::map<Addr, std::list<MsgPtr> > StallMsgMapType;
 191
 192     /**
 193      * A map from line addresses to lists of stalled messages for that line.
 194      * If this buffer allows the receiver to stall messages, on a stall
 195      * request, the stalled message is removed from the m_prio_heap and placed
 196      * in the m_stall_msg_map. Messages are held there until the receiver
 197      * requests they be reanalyzed, at which point they are moved back to
 198      * m_prio_heap.
 199      *
 200      * NOTE: The stall map holds messages in the order in which they were
 201      * initially received, and when a line is unblocked, the messages are
 202      * moved back to the m_prio_heap in the same order. This prevents starving
 203      * older requests with younger ones.
 204      */
 205     StallMsgMapType m_stall_msg_map;
 206
 207     /**
 208      * A map from line addresses to corresponding vectors of messages that
 209      * are deferred for enqueueing. Messages in this map are waiting to be
 210      * enqueued into the message buffer.
 211      */
 212     typedef std::unordered_map<Addr, std::vector<MsgPtr>> DeferredMsgMapType;
 213     DeferredMsgMapType m_deferred_msg_map;
 214
 215     /**
 216      * Current size of the stall map.
 217      * Track the number of messages held in stall map lists. This is used to
 218      * ensure that if the buffer is finite-sized, it blocks further requests
 219      * when the m_prio_heap and m_stall_msg_map contain m_max_size messages.
 220      */
 221     int m_stall_map_size;
 222
 223     /**
 224      * The maximum capacity. For finite-sized buffers, m_max_size stores a
 225      * number greater than 0 to indicate the maximum allowed number of messages
 226      * in the buffer at any time. To get infinitely-sized buffers, set buffer
 227      * size: m_max_size = 0
 228      */
 229     const unsigned int m_max_size;
 230
 231     Tick m_time_last_time_size_checked;
 232     unsigned int m_size_last_time_size_checked;
 233
 234     // variables used so enqueues appear to happen immediately, while
 235     // pop happen the next cycle
 236     Tick m_time_last_time_enqueue;
 237     Tick m_time_last_time_pop;
 238     Tick m_last_arrival_time;
 239
 240     unsigned int m_size_at_cycle_start;
 241     unsigned int m_stalled_at_cycle_start;
 242     unsigned int m_msgs_this_cycle;
 243
 244     uint64_t m_msg_counter;
 245     int m_priority_rank;
 246     const bool m_strict_fifo;
 247     const MessageRandomization m_randomization;
 248     const bool m_allow_zero_latency;
 249
 250     int m_input_link_id;
 251     int m_vnet_id;
 252
 253     Stats::Scalar m_not_avail_count;  // count the # of times I didn't have N
 254                                       // slots available
 255     Stats::Average m_buf_msgs;
 256     Stats::Average m_stall_time;
 257     Stats::Scalar m_stall_count;
 258     Stats::Formula m_occupancy;
 259 };
 260
 261 Tick random_time();
 262
 263 inline std::ostream&
 264 operator<<(std::ostream& out, const MessageBuffer& obj)
 265 {
 266     obj.print(out);
 267     out << std::flush;
 268     return out;
 269 }
 270
 271 #endif //__MEM_RUBY_NETWORK_MESSAGEBUFFER_HH__