|  | // Mutex pool used to limit contention -*- C++ -*- | 
|  |  | 
|  | // Copyright (C) 2016-2021 Free Software Foundation, Inc. | 
|  | // | 
|  | // This file is part of the GNU ISO C++ Library.  This library is free | 
|  | // software; you can redistribute it and/or modify it under the | 
|  | // terms of the GNU General Public License as published by the | 
|  | // Free Software Foundation; either version 3, or (at your option) | 
|  | // any later version. | 
|  |  | 
|  | // This library is distributed in the hope that it will be useful, | 
|  | // but WITHOUT ANY WARRANTY; without even the implied warranty of | 
|  | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
|  | // GNU General Public License for more details. | 
|  |  | 
|  | // Under Section 7 of GPL version 3, you are granted additional | 
|  | // permissions described in the GCC Runtime Library Exception, version | 
|  | // 3.1, as published by the Free Software Foundation. | 
|  |  | 
|  | // You should have received a copy of the GNU General Public License and | 
|  | // a copy of the GCC Runtime Library Exception along with this program; | 
|  | // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see | 
|  | // <http://www.gnu.org/licenses/>. | 
|  |  | 
|  | namespace __gnu_internal _GLIBCXX_VISIBILITY(hidden) | 
|  | { | 
|  | const unsigned char mask = 0xf; | 
|  | const unsigned char invalid = mask + 1; | 
|  |  | 
|  | /* Returns different instances of __mutex depending on the passed index | 
|  | * in order to limit contention. | 
|  | */ | 
|  | __gnu_cxx::__mutex& get_mutex(unsigned char i); | 
|  | } |