16e6e1d72f
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@111751 91177308-0d34-0410-b5e6-96231b3b80d8
46 lines
923 B
C++
46 lines
923 B
C++
//===-------------------------- random.cpp --------------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "random"
|
|
#include "system_error"
|
|
|
|
#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
|