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