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