1 /* 2 Copyright (c) 2005-2020 Intel Corporation 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 #ifndef __TBB_null_mutex_H 18 #define __TBB_null_mutex_H 19 20 #include "tbb_stddef.h" 21 22 namespace tbb { 23 24 //! A mutex which does nothing 25 /** A null_mutex does no operation and simulates success. 26 @ingroup synchronization */ 27 class null_mutex : internal::mutex_copy_deprecated_and_disabled { 28 public: 29 //! Represents acquisition of a mutex. 30 class scoped_lock : internal::no_copy { 31 public: scoped_lock()32 scoped_lock() {} scoped_lock(null_mutex &)33 scoped_lock( null_mutex& ) {} ~scoped_lock()34 ~scoped_lock() {} acquire(null_mutex &)35 void acquire( null_mutex& ) {} try_acquire(null_mutex &)36 bool try_acquire( null_mutex& ) { return true; } release()37 void release() {} 38 }; 39 null_mutex()40 null_mutex() {} 41 42 // Mutex traits 43 static const bool is_rw_mutex = false; 44 static const bool is_recursive_mutex = true; 45 static const bool is_fair_mutex = true; 46 }; 47 48 } 49 50 #endif /* __TBB_null_mutex_H */ 51