src/base/random.cc

   1 /*
   2  * Copyright (c) 2014 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) 2003-2005 The Regents of The University of Michigan
  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  * Authors: Nathan Binkert
  41  *          Ali Saidi
  42  *          Andreas Hansson
  43  */
  44
  45 #include "base/random.hh"
  46
  47 #include <sstream>
  48
  49 #include "base/misc.hh"
  50 #include "sim/serialize.hh"
  51
  52 Random::Random()
  53 {
  54     // default random seed
  55     init(5489);
  56 }
  57
  58 Random::Random(uint32_t s)
  59 {
  60     init(s);
  61 }
  62
  63 Random::~Random()
  64 {
  65 }
  66
  67 void
  68 Random::init(uint32_t s)
  69 {
  70     gen.seed(s);
  71 }
  72
  73 void
  74 Random::serialize(CheckpointOut &cp) const
  75 {
  76     panic("Currently not used anywhere.\n");
  77
  78     // get the state from the generator
  79     std::ostringstream oss;
  80     oss << gen;
  81     std::string state = oss.str();
  82     paramOut(cp, "mt_state", state);
  83 }
  84
  85 void
  86 Random::unserialize(CheckpointIn &cp)
  87 {
  88     panic("Currently not used anywhere.\n");
  89
  90     // the random generator state did not use to be part of the
  91     // checkpoint state, so be forgiving in the unserialization and
  92     // keep on going if the parameter is not there
  93     std::string state;
  94     if (optParamIn(cp, "mt_state", state)) {
  95         std::istringstream iss(state);
  96         iss >> gen;
  97     }
  98 }
  99
 100 Random random_mt;