//===----------------------- random_shuffle.cpp ---------------------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#include "algorithm"

#include "random"

#ifndef _LIBCPP_HAS_NO_THREADS

#   include "mutex"

#   if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB)

#       pragma comment(lib, "pthread")

#   endif

#endif

_LIBCPP_BEGIN_NAMESPACE_STD

#ifndef _LIBCPP_HAS_NO_THREADS

_LIBCPP_SAFE_STATIC static __libcpp_mutex_t __rs_mut = _LIBCPP_MUTEX_INITIALIZER;

#endif

unsigned __rs_default::__c_ = 0;

__rs_default::__rs_default()

{

#ifndef _LIBCPP_HAS_NO_THREADS

    __libcpp_mutex_lock(&__rs_mut);

#endif

    __c_ = 1;

}

__rs_default::__rs_default(const __rs_default&)

{

    ++__c_;

}

__rs_default::~__rs_default()

{

#ifndef _LIBCPP_HAS_NO_THREADS

    if (--__c_ == 0)

       __libcpp_mutex_unlock(&__rs_mut);

#else

    --__c_;

#endif

}

__rs_default::result_type

__rs_default::operator()()

{

    static mt19937 __rs_g;

    return __rs_g();

}

__rs_default

__rs_get()

{

    return __rs_default();

}

_LIBCPP_END_NAMESPACE_STD