llvm-project/libcxx/src/random.cpp

49 lines
1002 B
C++

//===-------------------------- random.cpp --------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "random"
#include "system_error"
#ifdef __sun__
#define rename solaris_headers_are_broken
#endif
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
_LIBCPP_BEGIN_NAMESPACE_STD
random_device::random_device(const string& __token)
: __f_(open(__token.c_str(), O_RDONLY))
{
if (__f_ <= 0)
__throw_system_error(errno, ("random_device failed to open " + __token).c_str());
}
random_device::~random_device()
{
close(__f_);
}
unsigned
random_device::operator()()
{
unsigned r;
read(__f_, &r, sizeof(r));
return r;
}
double
random_device::entropy() const
{
return 0;
}
_LIBCPP_END_NAMESPACE_STD