1 //===-------------------------- random.cpp --------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "random" 11 #include "system_error" 12 13 #ifdef __sun__ 14 #define rename solaris_headers_are_broken 15 #endif 16 #include <fcntl.h> 17 #include <unistd.h> 18 #include <errno.h> 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 random_device::random_device(const string& __token) 23 : __f_(open(__token.c_str(), O_RDONLY)) 24 { 25 if (__f_ <= 0) 26 __throw_system_error(errno, ("random_device failed to open " + __token).c_str()); 27 } 28 29 random_device::~random_device() 30 { 31 close(__f_); 32 } 33 34 unsigned 35 random_device::operator()() 36 { 37 unsigned r; 38 read(__f_, &r, sizeof(r)); 39 return r; 40 } 41 42 double 43 random_device::entropy() const _NOEXCEPT 44 { 45 return 0; 46 } 47 48 _LIBCPP_END_NAMESPACE_STD 49
