queuing_rw_mutex.h

00001 /*
00002     Copyright 2005-2012 Intel Corporation.  All Rights Reserved.
00003 
00004     The source code contained or described herein and all documents related
00005     to the source code ("Material") are owned by Intel Corporation or its
00006     suppliers or licensors.  Title to the Material remains with Intel
00007     Corporation or its suppliers and licensors.  The Material is protected
00008     by worldwide copyright laws and treaty provisions.  No part of the
00009     Material may be used, copied, reproduced, modified, published, uploaded,
00010     posted, transmitted, distributed, or disclosed in any way without
00011     Intel's prior express written permission.
00012 
00013     No license under any patent, copyright, trade secret or other
00014     intellectual property right is granted to or conferred upon you by
00015     disclosure or delivery of the Materials, either expressly, by
00016     implication, inducement, estoppel or otherwise.  Any license under such
00017     intellectual property rights must be express and approved by Intel in
00018     writing.
00019 */
00020 
00021 #ifndef __TBB_queuing_rw_mutex_H
00022 #define __TBB_queuing_rw_mutex_H
00023 
00024 #include "tbb_config.h"
00025 
00026 #if !TBB_USE_EXCEPTIONS && _MSC_VER
00027     // Suppress "C++ exception handler used, but unwind semantics are not enabled" warning in STL headers
00028     #pragma warning (push)
00029     #pragma warning (disable: 4530)
00030 #endif
00031 
00032 #include <cstring>
00033 
00034 #if !TBB_USE_EXCEPTIONS && _MSC_VER
00035     #pragma warning (pop)
00036 #endif
00037 
00038 #include "atomic.h"
00039 #include "tbb_profiling.h"
00040 
00041 namespace tbb {
00042 
00044 
00047 class queuing_rw_mutex {
00048 public:
00050     queuing_rw_mutex() {
00051         q_tail = NULL;
00052 #if TBB_USE_THREADING_TOOLS
00053         internal_construct();
00054 #endif
00055     }
00056 
00058     ~queuing_rw_mutex() {
00059 #if TBB_USE_ASSERT
00060         __TBB_ASSERT( !q_tail, "destruction of an acquired mutex");
00061 #endif
00062     }
00063 
00065 
00067     class scoped_lock: internal::no_copy {
00069         void initialize() {
00070             my_mutex = NULL;
00071 #if TBB_USE_ASSERT
00072             my_state = 0xFF; // Set to invalid state
00073             internal::poison_pointer(my_next);
00074             internal::poison_pointer(my_prev);
00075 #endif /* TBB_USE_ASSERT */
00076         }
00077 
00078     public:
00080 
00081         scoped_lock() {initialize();}
00082 
00084         scoped_lock( queuing_rw_mutex& m, bool write=true ) {
00085             initialize();
00086             acquire(m,write);
00087         }
00088 
00090         ~scoped_lock() {
00091             if( my_mutex ) release();
00092         }
00093 
00095         void acquire( queuing_rw_mutex& m, bool write=true );
00096 
00098         bool try_acquire( queuing_rw_mutex& m, bool write=true );
00099 
00101         void release();
00102 
00104 
00105         bool upgrade_to_writer();
00106 
00108         bool downgrade_to_reader();
00109 
00110     private:
00112         queuing_rw_mutex* my_mutex;
00113 
00115         scoped_lock *__TBB_atomic my_prev, *__TBB_atomic my_next;
00116 
00117         typedef unsigned char state_t;
00118 
00120         atomic<state_t> my_state;
00121 
00123 
00124         unsigned char __TBB_atomic my_going;
00125 
00127         unsigned char my_internal_lock;
00128 
00130         void acquire_internal_lock();
00131 
00133 
00134         bool try_acquire_internal_lock();
00135 
00137         void release_internal_lock();
00138 
00140         void wait_for_release_of_internal_lock();
00141 
00143         void unblock_or_wait_on_internal_lock( uintptr_t );
00144     };
00145 
00146     void __TBB_EXPORTED_METHOD internal_construct();
00147 
00148     // Mutex traits
00149     static const bool is_rw_mutex = true;
00150     static const bool is_recursive_mutex = false;
00151     static const bool is_fair_mutex = true;
00152 
00153 private:
00155     atomic<scoped_lock*> q_tail;
00156 
00157 };
00158 
00159 __TBB_DEFINE_PROFILING_SET_NAME(queuing_rw_mutex)
00160 
00161 } // namespace tbb
00162 
00163 #endif /* __TBB_queuing_rw_mutex_H */

Copyright © 2005-2012 Intel Corporation. All Rights Reserved.

Intel, Pentium, Intel Xeon, Itanium, Intel XScale and VTune are registered trademarks or trademarks of Intel Corporation or its subsidiaries in the United States and other countries.

* Other names and brands may be claimed as the property of others.