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/
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10 modification, are permitted provided that the following conditions are met:
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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
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19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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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 atomics::atomic_thread_fence( atomics::memory_order_seq_cst );
77 pRec->m_nAccessControl.store( tmp + 1, atomics::memory_order_relaxed );
81 template <typename RCUtag>
82 inline void gp_thread_gc<RCUtag>::access_unlock()
84 thread_record * pRec = get_thread_record();
85 assert( pRec != nullptr );
87 uint32_t tmp = pRec->m_nAccessControl.load( atomics::memory_order_relaxed );
88 assert( (tmp & rcu_class::c_nNestMask) > 0 );
90 #if CDS_COMPILER == CDS_COMPILER_CLANG && CDS_COMPILER_VERSION < 30800
91 // CLang 3.6-3.7: some tests of intrusive::FeldmanHashSet based on general-purpose RCU
92 // are failed even in single-threaded mode (unit tests) without magic compiler barrier below
93 CDS_COMPILER_RW_BARRIER;
95 pRec->m_nAccessControl.store( tmp - 1, atomics::memory_order_release );
98 template <typename RCUtag>
99 inline bool gp_thread_gc<RCUtag>::is_locked()
101 thread_record * pRec = get_thread_record();
102 assert( pRec != nullptr );
104 return (pRec->m_nAccessControl.load( atomics::memory_order_relaxed ) & rcu_class::c_nNestMask) != 0;
109 template <typename RCUtag>
110 inline bool gp_singleton<RCUtag>::check_grace_period( typename gp_singleton<RCUtag>::thread_record * pRec ) const
112 uint32_t const v = pRec->m_nAccessControl.load( atomics::memory_order_acquire );
113 return (v & general_purpose_rcu::c_nNestMask)
114 && (( v ^ m_nGlobalControl.load( atomics::memory_order_relaxed )) & ~general_purpose_rcu::c_nNestMask );
117 template <typename RCUtag>
118 template <class Backoff>
119 inline void gp_singleton<RCUtag>::flip_and_wait( Backoff& bkoff )
121 OS::ThreadId const nullThreadId = OS::c_NullThreadId;
122 m_nGlobalControl.fetch_xor( general_purpose_rcu::c_nControlBit, atomics::memory_order_seq_cst );
124 for ( thread_record * pRec = m_ThreadList.head( atomics::memory_order_acquire ); pRec; pRec = pRec->m_list.m_pNext ) {
125 while ( pRec->m_list.m_idOwner.load( atomics::memory_order_acquire ) != nullThreadId && check_grace_period( pRec )) {
127 CDS_COMPILER_RW_BARRIER;
134 }}} // namespace cds:urcu::details
137 #endif // #ifndef CDSLIB_URCU_DETAILS_GP_H