random.hh revision 10349:939094c17866 
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/*
46 * Mersenne twister random number generator.
47 */
48
49#ifndef __BASE_RANDOM_HH__
50#define __BASE_RANDOM_HH__
51
52#include <random>
53#include <string>
54#include <type_traits>
55
56#include "base/types.hh"
57
58class Checkpoint;
59
60class Random
61{
62
63  private:
64
65    std::mt19937_64 gen;
66
67  public:
68
69    Random();
70    Random(uint32_t s);
71    ~Random();
72
73    void init(uint32_t s);
74
75    /**
76     * Use the SFINAE idiom to choose an implementation based on
77     * whether the type is integral or floating point.
78     */
79    template <typename T>
80    typename std::enable_if<std::is_integral<T>::value, T>::type
81    random()
82    {
83        // [0, max_value] for integer types
84        std::uniform_int_distribution<T> dist;
85        return dist(gen);
86    }
87
88    template <typename T>
89    typename std::enable_if<std::is_floating_point<T>::value, T>::type
90    random()
91    {
92        // [0, 1) for real types
93        std::uniform_real_distribution<T> dist;
94        return dist(gen);
95    }
96
97    template <typename T>
98    typename std::enable_if<std::is_integral<T>::value, T>::type
99    random(T min, T max)
100    {
101        std::uniform_int_distribution<T> dist(min, max);
102        return dist(gen);
103    }
104
105    void serialize(std::ostream &os);
106    void unserialize(Checkpoint *cp, const std::string &section);
107};
108
109extern Random random_mt;
110
111#endif // __BASE_RANDOM_HH__
112