| // random -*- C++ -*- |
| |
| // Copyright (C) 2012-2014 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| #include <random> |
| |
| #ifdef _GLIBCXX_USE_C99_STDINT_TR1 |
| |
| #if defined __i386__ || defined __x86_64__ |
| # include <cpuid.h> |
| #endif |
| |
| #include <cstdio> |
| |
| #ifdef _GLIBCXX_HAVE_UNISTD_H |
| # include <unistd.h> |
| #endif |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| namespace |
| { |
| static unsigned long |
| _M_strtoul(const std::string& __str) |
| { |
| unsigned long __ret = 5489UL; |
| if (__str != "mt19937") |
| { |
| const char* __nptr = __str.c_str(); |
| char* __endptr; |
| __ret = std::strtoul(__nptr, &__endptr, 0); |
| if (*__nptr == '\0' || *__endptr != '\0') |
| std::__throw_runtime_error(__N("random_device::_M_strtoul" |
| "(const std::string&)")); |
| } |
| return __ret; |
| } |
| |
| #if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND |
| unsigned int |
| __attribute__ ((target("rdrnd"))) |
| __x86_rdrand(void) |
| { |
| unsigned int retries = 100; |
| unsigned int val; |
| |
| while (__builtin_ia32_rdrand32_step(&val) == 0) |
| if (--retries == 0) |
| std::__throw_runtime_error(__N("random_device::__x86_rdrand(void)")); |
| |
| return val; |
| } |
| #endif |
| } |
| |
| void |
| random_device::_M_init(const std::string& token) |
| { |
| const char *fname = token.c_str(); |
| |
| if (token == "default") |
| { |
| #if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND |
| unsigned int eax, ebx, ecx, edx; |
| // Check availability of cpuid and, for now at least, also the |
| // CPU signature for Intel's |
| if (__get_cpuid_max(0, &ebx) > 0 && ebx == signature_INTEL_ebx) |
| { |
| __cpuid(1, eax, ebx, ecx, edx); |
| if (ecx & bit_RDRND) |
| { |
| _M_file = nullptr; |
| return; |
| } |
| } |
| #endif |
| |
| fname = "/dev/urandom"; |
| } |
| else if (token != "/dev/urandom" && token != "/dev/random") |
| fail: |
| std::__throw_runtime_error(__N("random_device::" |
| "random_device(const std::string&)")); |
| |
| _M_file = static_cast<void*>(std::fopen(fname, "rb")); |
| if (!_M_file) |
| goto fail; |
| } |
| |
| void |
| random_device::_M_init_pretr1(const std::string& token) |
| { |
| _M_mt.seed(_M_strtoul(token)); |
| } |
| |
| void |
| random_device::_M_fini() |
| { |
| if (_M_file) |
| std::fclose(static_cast<FILE*>(_M_file)); |
| } |
| |
| random_device::result_type |
| random_device::_M_getval() |
| { |
| #if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND |
| if (!_M_file) |
| return __x86_rdrand(); |
| #endif |
| |
| result_type __ret; |
| #ifdef _GLIBCXX_HAVE_UNISTD_H |
| read(fileno(static_cast<FILE*>(_M_file)), |
| static_cast<void*>(&__ret), sizeof(result_type)); |
| #else |
| std::fread(static_cast<void*>(&__ret), sizeof(result_type), |
| 1, static_cast<FILE*>(_M_file)); |
| #endif |
| return __ret; |
| } |
| |
| random_device::result_type |
| random_device::_M_getval_pretr1() |
| { |
| return _M_mt(); |
| } |
| |
| template class mersenne_twister_engine< |
| uint_fast32_t, |
| 32, 624, 397, 31, |
| 0x9908b0dfUL, 11, |
| 0xffffffffUL, 7, |
| 0x9d2c5680UL, 15, |
| 0xefc60000UL, 18, 1812433253UL>; |
| } |
| #endif |