1 //===----------------------- random_shuffle.cpp ---------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "algorithm" 10 #include "random" 11 #ifndef _LIBCPP_HAS_NO_THREADS 12 # include "mutex" 13 # if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB) 14 # pragma comment(lib, "pthread") 15 # endif 16 #endif 17 18 _LIBCPP_BEGIN_NAMESPACE_STD 19 20 #ifndef _LIBCPP_HAS_NO_THREADS 21 _LIBCPP_SAFE_STATIC static __libcpp_mutex_t __rs_mut = _LIBCPP_MUTEX_INITIALIZER; 22 #endif 23 unsigned __rs_default::__c_ = 0; 24 25 __rs_default::__rs_default() 26 { 27 #ifndef _LIBCPP_HAS_NO_THREADS 28 __libcpp_mutex_lock(&__rs_mut); 29 #endif 30 __c_ = 1; 31 } 32 33 __rs_default::__rs_default(const __rs_default&) 34 { 35 ++__c_; 36 } 37 38 __rs_default::~__rs_default() 39 { 40 #ifndef _LIBCPP_HAS_NO_THREADS 41 if (--__c_ == 0) 42 __libcpp_mutex_unlock(&__rs_mut); 43 #else 44 --__c_; 45 #endif 46 } 47 48 __rs_default::result_type 49 __rs_default::operator()() 50 { 51 static mt19937 __rs_g; 52 return __rs_g(); 53 } 54 55 __rs_default 56 __rs_get() 57 { 58 return __rs_default(); 59 } 60 61 _LIBCPP_END_NAMESPACE_STD 62