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
22random_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
29random_device::~random_device()
30{
31    close(__f_);
32}
33
34unsigned
35random_device::operator()()
36{
37    unsigned r;
38    read(__f_, &r, sizeof(r));
39    return r;
40}
41
42double
43random_device::entropy() const _NOEXCEPT
44{
45    return 0;
46}
47
48_LIBCPP_END_NAMESPACE_STD
49