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
23 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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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28 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 #ifndef CDSLIB_URCU_DETAILS_SH_H
32 #define CDSLIB_URCU_DETAILS_SH_H
34 #include <memory.h> //memset
35 #include <cds/urcu/details/sh_decl.h>
37 #ifdef CDS_URCU_SIGNAL_HANDLING_ENABLED
38 #include <cds/threading/model.h>
41 namespace cds { namespace urcu { namespace details {
46 template <typename RCUtag>
47 inline sh_thread_gc<RCUtag>::sh_thread_gc()
49 if ( !threading::Manager::isThreadAttached())
50 cds::threading::Manager::attachThread();
53 template <typename RCUtag>
54 inline sh_thread_gc<RCUtag>::~sh_thread_gc()
56 cds::threading::Manager::detachThread();
59 template <typename RCUtag>
60 inline typename sh_thread_gc<RCUtag>::thread_record * sh_thread_gc<RCUtag>::get_thread_record()
62 return cds::threading::getRCU<RCUtag>();
65 template <typename RCUtag>
66 inline void sh_thread_gc<RCUtag>::access_lock()
68 thread_record * pRec = get_thread_record();
69 assert( pRec != nullptr );
71 uint32_t tmp = pRec->m_nAccessControl.load( atomics::memory_order_relaxed );
72 assert( ( tmp & rcu_class::c_nNestMask ) > 0 );
74 if ( (tmp & rcu_class::c_nNestMask) == 0 ) {
75 pRec->m_nAccessControl.store( sh_singleton<RCUtag>::instance()->global_control_word(atomics::memory_order_relaxed),
76 atomics::memory_order_relaxed );
79 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 sh_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 sh_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 void sh_singleton<RCUtag>::set_signal_handler()
113 //TODO: OS-specific code must be moved to cds::OS namespace
114 struct sigaction sigact;
115 memset( &sigact, 0, sizeof(sigact));
116 sigact.sa_sigaction = signal_handler;
117 sigact.sa_flags = SA_SIGINFO;
118 sigemptyset( &sigact.sa_mask );
119 sigaction( m_nSigNo, &sigact, nullptr );
121 sigaddset( &sigact.sa_mask, m_nSigNo );
122 pthread_sigmask( SIG_UNBLOCK, &sigact.sa_mask, nullptr );
125 template <typename RCUtag>
126 inline void sh_singleton<RCUtag>::clear_signal_handler()
129 template <typename RCUtag>
130 inline void sh_singleton<RCUtag>::raise_signal( cds::OS::ThreadId tid )
132 pthread_kill( tid, m_nSigNo );
135 template <typename RCUtag>
136 template <class Backoff>
137 inline void sh_singleton<RCUtag>::force_membar_all_threads( Backoff& bkOff )
139 OS::ThreadId const nullThreadId = OS::c_NullThreadId;
141 // Send "need membar" signal to all RCU threads
142 for ( thread_record * pRec = m_ThreadList.head( atomics::memory_order_acquire); pRec; pRec = pRec->m_list.m_pNext ) {
143 OS::ThreadId tid = pRec->m_list.m_idOwner.load( atomics::memory_order_acquire);
144 if ( tid != nullThreadId ) {
145 pRec->m_bNeedMemBar.store( true, atomics::memory_order_release );
150 // Wait while all RCU threads process the signal
151 for ( thread_record * pRec = m_ThreadList.head( atomics::memory_order_acquire); pRec; pRec = pRec->m_list.m_pNext ) {
152 OS::ThreadId tid = pRec->m_list.m_idOwner.load( atomics::memory_order_acquire);
153 if ( tid != nullThreadId ) {
155 while ( (tid = pRec->m_list.m_idOwner.load( atomics::memory_order_acquire )) != nullThreadId
156 && pRec->m_bNeedMemBar.load( atomics::memory_order_acquire ))
158 // Some versions of OSes can lose signals
159 // So, we resend the signal
167 template <typename RCUtag>
168 bool sh_singleton<RCUtag>::check_grace_period( thread_record * pRec ) const
170 uint32_t const v = pRec->m_nAccessControl.load( atomics::memory_order_acquire );
171 return (v & signal_handling_rcu::c_nNestMask)
172 && ((( v ^ m_nGlobalControl.load( atomics::memory_order_relaxed )) & ~signal_handling_rcu::c_nNestMask ));
175 template <typename RCUtag>
176 template <class Backoff>
177 void sh_singleton<RCUtag>::wait_for_quiescent_state( Backoff& bkOff )
179 OS::ThreadId const nullThreadId = OS::c_NullThreadId;
181 for ( thread_record * pRec = m_ThreadList.head( atomics::memory_order_acquire); pRec; pRec = pRec->m_list.m_pNext ) {
182 while ( pRec->m_list.m_idOwner.load( atomics::memory_order_acquire) != nullThreadId && check_grace_period( pRec ))
187 }}} // namespace cds:urcu::details
190 #endif // #ifdef CDS_URCU_SIGNAL_HANDLING_ENABLED
191 #endif // #ifndef CDSLIB_URCU_DETAILS_SH_H