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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24 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
26 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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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 pRec->m_nAccessControl.store( tmp - 1, atomics::memory_order_release );
93 template <typename RCUtag>
94 inline bool gp_thread_gc<RCUtag>::is_locked()
96 thread_record * pRec = get_thread_record();
97 assert( pRec != nullptr );
99 return (pRec->m_nAccessControl.load( atomics::memory_order_relaxed ) & rcu_class::c_nNestMask) != 0;
104 template <typename RCUtag>
105 inline bool gp_singleton<RCUtag>::check_grace_period( typename gp_singleton<RCUtag>::thread_record * pRec ) const
107 uint32_t const v = pRec->m_nAccessControl.load( atomics::memory_order_acquire );
108 return (v & general_purpose_rcu::c_nNestMask)
109 && (( v ^ m_nGlobalControl.load( atomics::memory_order_relaxed )) & ~general_purpose_rcu::c_nNestMask );
112 template <typename RCUtag>
113 template <class Backoff>
114 inline void gp_singleton<RCUtag>::flip_and_wait( Backoff& bkoff )
116 OS::ThreadId const nullThreadId = OS::c_NullThreadId;
117 m_nGlobalControl.fetch_xor( general_purpose_rcu::c_nControlBit, atomics::memory_order_seq_cst );
119 for ( thread_record * pRec = m_ThreadList.head( atomics::memory_order_acquire ); pRec; pRec = pRec->m_list.m_pNext ) {
120 while ( pRec->m_list.m_idOwner.load( atomics::memory_order_acquire ) != nullThreadId && check_grace_period( pRec )) {
122 CDS_COMPILER_RW_BARRIER;
129 }}} // namespace cds:urcu::details
132 #endif // #ifndef CDSLIB_URCU_DETAILS_GP_H