2 This file is a part of libcds - Concurrent Data Structures library
4 (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
6 Source code repo: http://github.com/khizmax/libcds/
7 Download: http://sourceforge.net/projects/libcds/files/
9 Redistribution and use in source and binary forms, with or without
10 modification, are permitted provided that the following conditions are met:
12 * Redistributions of source code must retain the above copyright notice, this
13 list of conditions and the following disclaimer.
15 * Redistributions in binary form must reproduce the above copyright notice,
16 this list of conditions and the following disclaimer in the documentation
17 and/or other materials provided with the distribution.
19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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31 #ifndef CDSLIB_URCU_DETAILS_GP_H
32 #define CDSLIB_URCU_DETAILS_GP_H
34 #include <cds/urcu/details/gp_decl.h>
35 #include <cds/threading/model.h>
38 namespace cds { namespace urcu { namespace details {
43 template <typename RCUtag>
44 inline gp_thread_gc<RCUtag>::gp_thread_gc()
46 if ( !threading::Manager::isThreadAttached())
47 cds::threading::Manager::attachThread();
50 template <typename RCUtag>
51 inline gp_thread_gc<RCUtag>::~gp_thread_gc()
53 cds::threading::Manager::detachThread();
56 template <typename RCUtag>
57 inline typename gp_thread_gc<RCUtag>::thread_record * gp_thread_gc<RCUtag>::get_thread_record()
59 return cds::threading::getRCU<RCUtag>();
62 template <typename RCUtag>
63 inline void gp_thread_gc<RCUtag>::access_lock()
65 thread_record * pRec = get_thread_record();
66 assert( pRec != nullptr );
68 uint32_t tmp = pRec->m_nAccessControl.load( atomics::memory_order_relaxed );
69 if ( (tmp & rcu_class::c_nNestMask) == 0 ) {
70 pRec->m_nAccessControl.store( gp_singleton<RCUtag>::instance()->global_control_word(atomics::memory_order_relaxed),
71 atomics::memory_order_relaxed );
73 # if CDS_COMPILER == CDS_COMPILER_CLANG && CDS_COMPILER_VERSION < 30800
74 // Seems, CLang 3.6-3.7 cannot handle acquire barrier correctly
75 CDS_COMPILER_RW_BARRIER;
78 pRec->m_nAccessControl.load( atomics::memory_order_acquire );
83 pRec->m_nAccessControl.store( tmp + 1, atomics::memory_order_relaxed );
87 template <typename RCUtag>
88 inline void gp_thread_gc<RCUtag>::access_unlock()
90 thread_record * pRec = get_thread_record();
91 assert( pRec != nullptr );
93 uint32_t tmp = pRec->m_nAccessControl.load( atomics::memory_order_relaxed );
94 assert( (tmp & rcu_class::c_nNestMask) > 0 );
96 pRec->m_nAccessControl.store( tmp - 1, atomics::memory_order_release );
99 template <typename RCUtag>
100 inline bool gp_thread_gc<RCUtag>::is_locked()
102 thread_record * pRec = get_thread_record();
103 assert( pRec != nullptr );
105 return (pRec->m_nAccessControl.load( atomics::memory_order_relaxed ) & rcu_class::c_nNestMask) != 0;
110 template <typename RCUtag>
111 inline bool gp_singleton<RCUtag>::check_grace_period( typename gp_singleton<RCUtag>::thread_record * pRec ) const
113 uint32_t const v = pRec->m_nAccessControl.load( atomics::memory_order_acquire );
114 return (v & general_purpose_rcu::c_nNestMask)
115 && (( v ^ m_nGlobalControl.load( atomics::memory_order_relaxed )) & ~general_purpose_rcu::c_nNestMask );
118 template <typename RCUtag>
119 template <class Backoff>
120 inline void gp_singleton<RCUtag>::flip_and_wait( Backoff& bkoff )
122 OS::ThreadId const nullThreadId = OS::c_NullThreadId;
123 m_nGlobalControl.fetch_xor( general_purpose_rcu::c_nControlBit, atomics::memory_order_seq_cst );
125 for ( thread_record * pRec = m_ThreadList.head( atomics::memory_order_acquire ); pRec; pRec = pRec->m_list.m_pNext ) {
126 while ( pRec->m_list.m_idOwner.load( atomics::memory_order_acquire ) != nullThreadId && check_grace_period( pRec )) {
128 CDS_COMPILER_RW_BARRIER;
135 }}} // namespace cds:urcu::details
138 #endif // #ifndef CDSLIB_URCU_DETAILS_GP_H