src/mem/ruby/system/TimerTable.cc

   1
   2 /*
   3  * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met: redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer;
  10  * redistributions in binary form must reproduce the above copyright
  11  * notice, this list of conditions and the following disclaimer in the
  12  * documentation and/or other materials provided with the distribution;
  13  * neither the name of the copyright holders nor the names of its
  14  * contributors may be used to endorse or promote products derived from
  15  * this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  20  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  23  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * $Id$
  32  */
  33
  34 #include "mem/ruby/common/Global.hh"
  35 #include "mem/ruby/system/TimerTable.hh"
  36 #include "mem/ruby/eventqueue/RubyEventQueue.hh"
  37
  38 TimerTable::TimerTable()
  39 {
  40   m_consumer_ptr  = NULL;
  41   m_next_valid = false;
  42   m_next_address = Address(0);
  43   m_next_time = 0;
  44 }
  45
  46
  47 bool TimerTable::isReady() const
  48 {
  49   if (m_map.size() == 0) {
  50     return false;
  51   }
  52
  53   if (!m_next_valid) {
  54     updateNext();
  55   }
  56   assert(m_next_valid);
  57   return (g_eventQueue_ptr->getTime() >= m_next_time);
  58 }
  59
  60 const Address& TimerTable::readyAddress() const
  61 {
  62   assert(isReady());
  63
  64   if (!m_next_valid) {
  65     updateNext();
  66   }
  67   assert(m_next_valid);
  68   return m_next_address;
  69 }
  70
  71 void TimerTable::set(const Address& address, Time relative_latency)
  72 {
  73   assert(address == line_address(address));
  74   assert(relative_latency > 0);
  75   assert(m_map.exist(address) == false);
  76   Time ready_time = g_eventQueue_ptr->getTime() + relative_latency;
  77   m_map.add(address, ready_time);
  78   assert(m_consumer_ptr != NULL);
  79   g_eventQueue_ptr->scheduleEventAbsolute(m_consumer_ptr, ready_time);
  80   m_next_valid = false;
  81
  82   // Don't always recalculate the next ready address
  83   if (ready_time <= m_next_time) {
  84     m_next_valid = false;
  85   }
  86 }
  87
  88 void TimerTable::unset(const Address& address)
  89 {
  90   assert(address == line_address(address));
  91   assert(m_map.exist(address) == true);
  92   m_map.remove(address);
  93
  94   // Don't always recalculate the next ready address
  95   if (address == m_next_address) {
  96     m_next_valid = false;
  97   }
  98 }
  99
 100 void TimerTable::print(ostream& out) const
 101 {
 102 }
 103
 104
 105 void TimerTable::updateNext() const
 106 {
 107   if (m_map.size() == 0) {
 108     assert(m_next_valid == false);
 109     return;
 110   }
 111
 112   Vector<Address> addresses = m_map.keys();
 113   m_next_address = addresses[0];
 114   m_next_time = m_map.lookup(m_next_address);
 115
 116   // Search for the minimum time
 117   int size = addresses.size();
 118   for (int i=1; i<size; i++) {
 119     Address maybe_next_address = addresses[i];
 120     Time maybe_next_time = m_map.lookup(maybe_next_address);
 121     if (maybe_next_time < m_next_time) {
 122       m_next_time = maybe_next_time;
 123       m_next_address= maybe_next_address;
 124     }
 125   }
 126   m_next_valid = true;
 127 }