2 This file is a part of libcds - Concurrent Data Structures library
4 (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2016
6 Source code repo: http://github.com/khizmax/libcds/
7 Download: http://sourceforge.net/projects/libcds/files/
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31 #ifndef CDSLIB_ALGO_FLAT_COMBINING_KERNEL_H
32 #define CDSLIB_ALGO_FLAT_COMBINING_KERNEL_H
34 #include <cds/algo/flat_combining/defs.h>
35 #include <cds/algo/flat_combining/wait_strategy.h>
37 #include <cds/sync/spinlock.h>
38 #include <cds/details/allocator.h>
39 #include <cds/opt/options.h>
40 #include <cds/algo/int_algo.h>
42 namespace cds { namespace algo {
44 /// @defgroup cds_flat_combining_intrusive Intrusive flat combining containers
45 /// @defgroup cds_flat_combining_container Non-intrusive flat combining containers
49 @anchor cds_flat_combining_description
50 Flat combining (FC) technique is invented by Hendler, Incze, Shavit and Tzafrir in their paper
51 [2010] <i>"Flat Combining and the Synchronization-Parallelism Tradeoff"</i>.
52 The technique converts a sequential data structure to its concurrent implementation.
53 A few structures are added to the sequential implementation: a <i>global lock</i>,
54 a <i>count</i> of the number of combining passes, and a pointer to the <i>head</i>
55 of a <i>publication list</i>. The publication list is a list of thread-local records
56 of a size proportional to the number of threads that are concurrently accessing the shared object.
58 Each thread \p t accessing the structure to perform an invocation of some method \p f()
59 on the shared object executes the following sequence of steps:
61 <li>Write the invocation opcode and parameters (if any) of the method \p f() to be applied
62 sequentially to the shared object in the <i>request</i> field of your thread local publication
63 record (there is no need to use a load-store memory barrier). The <i>request</i> field will later
64 be used to receive the response. If your thread local publication record is marked as active
65 continue to step 2, otherwise continue to step 5.</li>
66 <li>Check if the global lock is taken. If so (another thread is an active combiner), spin on the <i>request</i>
67 field waiting for a response to the invocation (one can add a yield at this point to allow other threads
68 on the same core to run). Once in a while while spinning check if the lock is still taken and that your
69 record is active (you may use any of \p wait_strategy instead of spinning). If your record is inactive proceed to step 5.
70 Once the response is available, reset the request field to null and return the response.</li>
71 <li>If the lock is not taken, attempt to acquire it and become a combiner. If you fail,
72 return to spinning in step 2.</li>
73 <li>Otherwise, you hold the lock and are a combiner.
75 <li>Increment the combining pass count by one.</li>
76 <li>Execute a \p fc_apply() by traversing the publication list from the head,
77 combining all non-null method call invocations, setting the <i>age</i> of each of these records
78 to the current <i>count</i>, applying the combined method calls to the structure D, and returning
79 responses to all the invocations. This traversal is guaranteed to be wait-free.</li>
80 <li>If the <i>count</i> is such that a cleanup needs to be performed, traverse the publication
81 list from the <i>head</i>. Starting from the second item (we always leave the item pointed to
82 by the head in the list), remove from the publication list all records whose <i>age</i> is
83 much smaller than the current <i>count</i>. This is done by removing the node and marking it
85 <li>Release the lock.</li>
87 <li>If you have no thread local publication record allocate one, marked as active. If you already
88 have one marked as inactive, mark it as active. Execute a store-load memory barrier. Proceed to insert
89 the record into the list with a successful CAS to the <i>head</i>. Then proceed to step 1.</li>
92 As the test results show, the flat combining technique is suitable for non-intrusive containers
93 like stack, queue, deque. For intrusive concurrent containers the flat combining demonstrates
94 less impressive results.
96 \ref cds_flat_combining_container "List of FC-based containers" in libcds.
98 \ref cds_flat_combining_intrusive "List of intrusive FC-based containers" in libcds.
100 namespace flat_combining {
102 /// Flat combining internal statistics
103 template <typename Counter = cds::atomicity::event_counter >
106 typedef Counter counter_type; ///< Event counter type
108 counter_type m_nOperationCount ; ///< How many operations have been performed
109 counter_type m_nCombiningCount ; ///< Combining call count
110 counter_type m_nCompactPublicationList; ///< Count of publication list compacting
111 counter_type m_nDeactivatePubRecord; ///< How many publication records were deactivated during compacting
112 counter_type m_nActivatePubRecord; ///< Count of publication record activating
113 counter_type m_nPubRecordCreated ; ///< Count of created publication records
114 counter_type m_nPubRecordDeleted ; ///< Count of deleted publication records
115 counter_type m_nPassiveWaitCall; ///< Count of passive waiting call (\p kernel::wait_for_combining())
116 counter_type m_nPassiveWaitIteration;///< Count of iteration inside passive waiting
117 counter_type m_nPassiveWaitWakeup; ///< Count of forcing wake-up of passive wait cycle
118 counter_type m_nInvokeExclusive; ///< Count of call \p kernel::invoke_exclusive()
119 counter_type m_nWakeupByNotifying; ///< How many times the passive thread be waked up by a notification
120 counter_type m_nPassiveToCombiner; ///< How many times the passive thread becomes the combiner
122 /// Returns current combining factor
124 Combining factor is how many operations perform in one combine pass:
125 <tt>combining_factor := m_nOperationCount / m_nCombiningCount</tt>
127 double combining_factor() const
129 return m_nCombiningCount.get() ? double( m_nOperationCount.get()) / m_nCombiningCount.get() : 0.0;
133 void onOperation() { ++m_nOperationCount; }
134 void onCombining() { ++m_nCombiningCount; }
135 void onCompactPublicationList() { ++m_nCompactPublicationList; }
136 void onDeactivatePubRecord() { ++m_nDeactivatePubRecord; }
137 void onActivatePubRecord() { ++m_nActivatePubRecord; }
138 void onCreatePubRecord() { ++m_nPubRecordCreated; }
139 void onDeletePubRecord() { ++m_nPubRecordDeleted; }
140 void onPassiveWait() { ++m_nPassiveWaitCall; }
141 void onPassiveWaitIteration() { ++m_nPassiveWaitIteration; }
142 void onPassiveWaitWakeup() { ++m_nPassiveWaitWakeup; }
143 void onInvokeExclusive() { ++m_nInvokeExclusive; }
144 void onWakeupByNotifying() { ++m_nWakeupByNotifying; }
145 void onPassiveToCombiner() { ++m_nPassiveToCombiner; }
150 /// Flat combining dummy internal statistics
154 void onOperation() const {}
155 void onCombining() const {}
156 void onCompactPublicationList() const {}
157 void onDeactivatePubRecord() const {}
158 void onActivatePubRecord() const {}
159 void onCreatePubRecord() const {}
160 void onDeletePubRecord() const {}
161 void onPassiveWait() const {}
162 void onPassiveWaitIteration() const {}
163 void onPassiveWaitWakeup() const {}
164 void onInvokeExclusive() const {}
165 void onWakeupByNotifying() const {}
166 void onPassiveToCombiner() const {}
170 /// Type traits of \ref kernel class
172 You can define different type traits for \ref kernel
173 by specifying your struct based on \p %traits
174 or by using \ref make_traits metafunction.
178 typedef cds::sync::spin lock_type; ///< Lock type
179 typedef cds::algo::flat_combining::wait_strategy::backoff< cds::backoff::delay_of<2>> wait_strategy; ///< Wait strategy
180 typedef CDS_DEFAULT_ALLOCATOR allocator; ///< Allocator used for TLS data (allocating \p publication_record derivatives)
181 typedef empty_stat stat; ///< Internal statistics
182 typedef opt::v::relaxed_ordering memory_model; ///< /// C++ memory ordering model
185 /// Metafunction converting option list to traits
188 - \p opt::lock_type - mutex type, default is \p cds::sync::spin
189 - \p opt::wait_strategy - wait strategy, see \p wait_strategy namespace, default is \p wait_strategy::backoff.
190 - \p opt::allocator - allocator type, default is \ref CDS_DEFAULT_ALLOCATOR
191 - \p opt::stat - internal statistics, possible type: \ref stat, \ref empty_stat (the default)
192 - \p opt::memory_model - C++ memory ordering model.
193 List of all available memory ordering see \p opt::memory_model.
194 Default is \p cds::opt::v::relaxed_ordering
196 template <typename... Options>
198 # ifdef CDS_DOXYGEN_INVOKED
199 typedef implementation_defined type ; ///< Metafunction result
201 typedef typename cds::opt::make_options<
202 typename cds::opt::find_type_traits< traits, Options... >::type
208 /// The kernel of flat combining
211 - \p PublicationRecord - a type derived from \ref publication_record
212 - \p Traits - a type traits of flat combining, default is \p flat_combining::traits.
213 \ref make_traits metafunction can be used to create type traits
215 The kernel object should be a member of a container class. The container cooperates with flat combining
216 kernel object. There are two ways to interact with the kernel:
217 - One-by-one processing the active records of the publication list. This mode provides by \p combine() function:
218 the container acquires its publication record by \p acquire_record(), fills its fields and calls
219 \p combine() function of its kernel object. If the current thread becomes a combiner, the kernel
220 calls \p fc_apply() function of the container for each active non-empty record. Then, the container
221 should release its publication record by \p release_record(). Only one pass through the publication
223 - Batch processing - \p batch_combine() function. It this mode the container obtains access
224 to entire publication list. This mode allows the container to perform an elimination, for example,
225 the stack can collide \p push() and \p pop() requests. The sequence of invocations is the following:
226 the container acquires its publication record by \p acquire_record(), fills its field and call
227 \p batch_combine() function of its kernel object. If the current thread becomes a combiner,
228 the kernel calls \p fc_process() function of the container passing two iterators pointing to
229 the begin and the end of publication list (see \ref iterator class). The iterators allow
230 multiple pass through active records of publication list. For each processed record the container
231 should call \p operation_done() function. On the end, the container should release
232 its record by \p release_record().
235 typename PublicationRecord
236 ,typename Traits = traits
241 typedef Traits traits; ///< Type traits
242 typedef typename traits::lock_type global_lock_type; ///< Global lock type
243 typedef typename traits::wait_strategy wait_strategy; ///< Wait strategy type
244 typedef typename traits::allocator allocator; ///< Allocator type (used for allocating publication_record_type data)
245 typedef typename traits::stat stat; ///< Internal statistics
246 typedef typename traits::memory_model memory_model; ///< C++ memory model
248 typedef typename wait_strategy::template make_publication_record<PublicationRecord>::type publication_record_type; ///< Publication record type
252 typedef cds::details::Allocator< publication_record_type, allocator > cxx11_allocator; ///< internal helper cds::details::Allocator
253 typedef std::lock_guard<global_lock_type> lock_guard;
257 atomics::atomic<unsigned int> m_nCount; ///< Total count of combining passes. Used as an age.
258 publication_record_type * m_pHead; ///< Head of publication list
259 boost::thread_specific_ptr< publication_record_type > m_pThreadRec; ///< Thread-local publication record
260 mutable global_lock_type m_Mutex; ///< Global mutex
261 mutable stat m_Stat; ///< Internal statistics
262 unsigned int const m_nCompactFactor; ///< Publication list compacting factor (the list will be compacted through \p %m_nCompactFactor combining passes)
263 unsigned int const m_nCombinePassCount; ///< Number of combining passes
264 wait_strategy m_waitStrategy; ///< Wait strategy
267 /// Initializes the object
269 Compact factor = 1024
271 Combiner pass count = 8
277 /// Initializes the object
279 unsigned int nCompactFactor ///< Publication list compacting factor (the list will be compacted through \p nCompactFactor combining passes)
280 ,unsigned int nCombinePassCount ///< Number of combining passes for combiner thread
284 , m_pThreadRec( tls_cleanup )
285 , m_nCompactFactor( (unsigned int)( cds::beans::ceil2( nCompactFactor ) - 1 )) // binary mask
286 , m_nCombinePassCount( nCombinePassCount )
291 /// Destroys the objects and mark all publication records as inactive
294 m_pThreadRec.reset(); // calls tls_cleanup()
296 // delete all publication records
297 for ( publication_record* p = m_pHead; p; ) {
298 publication_record * pRec = p;
299 p = p->pNext.load( memory_model::memory_order_relaxed );
300 free_publication_record( static_cast<publication_record_type *>( pRec ));
304 /// Gets publication list record for the current thread
306 If there is no publication record for the current thread
307 the function allocates it.
309 publication_record_type * acquire_record()
311 publication_record_type * pRec = m_pThreadRec.get();
313 // Allocate new publication record
314 pRec = cxx11_allocator().New();
315 m_pThreadRec.reset( pRec );
316 m_Stat.onCreatePubRecord();
319 if ( pRec->nState.load( memory_model::memory_order_acquire ) != active )
322 assert( pRec->op() == req_EmptyRecord );
327 /// Marks publication record for the current thread as empty
328 void release_record( publication_record_type * pRec )
330 assert( pRec->is_done());
331 pRec->nRequest.store( req_EmptyRecord, memory_model::memory_order_release );
334 /// Trying to execute operation \p nOpId
336 \p pRec is the publication record acquiring by \ref acquire_record earlier.
337 \p owner is a container that is owner of flat combining kernel object.
338 As a result the current thread can become a combiner or can wait for
339 another combiner performs \p pRec operation.
341 If the thread becomes a combiner, the kernel calls \p owner.fc_apply
342 for each active non-empty publication record.
344 template <class Container>
345 void combine( unsigned int nOpId, publication_record_type * pRec, Container& owner )
347 assert( nOpId >= req_Operation );
350 pRec->nRequest.store( nOpId, memory_model::memory_order_release );
351 m_Stat.onOperation();
353 try_combining( owner, pRec );
356 /// Trying to execute operation \p nOpId in batch-combine mode
358 \p pRec is the publication record acquiring by \p acquire_record() earlier.
359 \p owner is a container that owns flat combining kernel object.
360 As a result the current thread can become a combiner or can wait for
361 another combiner performs \p pRec operation.
363 If the thread becomes a combiner, the kernel calls \p owner.fc_process()
364 giving the container the full access over publication list. This function
365 is useful for an elimination technique if the container supports any kind of
366 that. The container can perform multiple pass through publication list.
368 \p owner.fc_process() has two arguments - forward iterators on begin and end of
369 publication list, see \ref iterator class. For each processed record the container
370 should call \p operation_done() function to mark the record as processed.
372 On the end of \p %batch_combine the \p combine() function is called
373 to process rest of publication records.
375 template <class Container>
376 void batch_combine( unsigned int nOpId, publication_record_type* pRec, Container& owner )
378 assert( nOpId >= req_Operation );
381 pRec->nRequest.store( nOpId, memory_model::memory_order_release );
382 m_Stat.onOperation();
384 try_batch_combining( owner, pRec );
387 /// Invokes \p Func in exclusive mode
389 Some operation in flat combining containers should be called in exclusive mode
390 i.e the current thread should become the combiner to process the operation.
391 The typical example is \p empty() function.
393 \p %invoke_exclusive() allows do that: the current thread becomes the combiner,
394 invokes \p f exclusively but unlike a typical usage the thread does not process any pending request.
395 Instead, after end of \p f call the current thread wakes up a pending thread if any.
397 template <typename Func>
398 void invoke_exclusive( Func f )
401 lock_guard l( m_Mutex );
404 m_waitStrategy.wakeup( *this );
405 m_Stat.onInvokeExclusive();
408 /// Marks \p rec as executed
410 This function should be called by container if \p batch_combine mode is used.
411 For usual combining (see \p combine()) this function is excess.
413 void operation_done( publication_record& rec )
415 rec.nRequest.store( req_Response, memory_model::memory_order_release );
416 m_waitStrategy.notify( *this, static_cast<publication_record_type&>( rec ));
419 /// Internal statistics
420 stat const& statistics() const
426 // For container classes based on flat combining
427 stat& internal_statistics() const
433 /// Returns the compact factor
434 unsigned int compact_factor() const
436 return m_nCompactFactor + 1;
439 /// Returns number of combining passes for combiner thread
440 unsigned int combine_pass_count() const
442 return m_nCombinePassCount;
446 /// Publication list iterator
448 Iterators are intended for batch processing by container's
449 \p fc_process function.
450 The iterator allows iterate through active publication list.
456 publication_record_type * m_pRec;
461 iterator( publication_record_type * pRec )
469 while ( m_pRec && (m_pRec->nState.load( memory_model::memory_order_acquire ) != active
470 || m_pRec->op( memory_model::memory_order_relaxed) < req_Operation ))
472 m_pRec = static_cast<publication_record_type*>(m_pRec->pNext.load( memory_model::memory_order_acquire ));
478 /// Initializes an empty iterator object
484 iterator( iterator const& src )
485 : m_pRec( src.m_pRec )
489 iterator& operator++()
492 m_pRec = static_cast<publication_record_type *>( m_pRec->pNext.load( memory_model::memory_order_acquire ));
498 iterator operator++(int)
506 /// Dereference operator, can return \p nullptr
507 publication_record_type* operator ->()
512 /// Dereference operator, the iterator should not be an end iterator
513 publication_record_type& operator*()
519 /// Iterator equality
520 friend bool operator==( iterator it1, iterator it2 )
522 return it1.m_pRec == it2.m_pRec;
525 /// Iterator inequality
526 friend bool operator!=( iterator it1, iterator it2 )
528 return !( it1 == it2 );
532 /// Returns an iterator to the first active publication record
533 iterator begin() { return iterator(m_pHead); }
535 /// Returns an iterator to the end of publication list. Should not be dereferenced.
536 iterator end() { return iterator(); }
539 /// Gets current value of \p rec.nRequest
541 This function is intended for invoking from a wait strategy
543 int get_operation( publication_record& rec )
545 return rec.op( memory_model::memory_order_acquire );
548 /// Wakes up any waiting thread
550 This function is intended for invoking from a wait strategy
554 publication_record* pRec = m_pHead;
556 if ( pRec->nState.load( memory_model::memory_order_acquire ) == active
557 && pRec->op( memory_model::memory_order_acquire ) >= req_Operation )
559 m_waitStrategy.notify( *this, static_cast<publication_record_type&>( *pRec ));
562 pRec = pRec->pNext.load( memory_model::memory_order_acquire );
568 static void tls_cleanup( publication_record_type* pRec )
571 // pRec that is TLS data should be excluded from publication list
572 pRec->nState.store( removed, memory_model::memory_order_release );
575 static void free_publication_record( publication_record_type* pRec )
577 cxx11_allocator().Delete( pRec );
582 assert( m_pThreadRec.get() == nullptr );
583 publication_record_type* pRec = cxx11_allocator().New();
585 m_pThreadRec.reset( pRec );
586 m_Stat.onCreatePubRecord();
589 void publish( publication_record_type* pRec )
591 assert( pRec->nState.load( memory_model::memory_order_relaxed ) == inactive );
593 pRec->nAge.store( m_nCount.load(memory_model::memory_order_relaxed), memory_model::memory_order_release );
594 pRec->nState.store( active, memory_model::memory_order_release );
596 // Insert record to publication list
597 if ( m_pHead != static_cast<publication_record *>(pRec)) {
598 publication_record * p = m_pHead->pNext.load(memory_model::memory_order_relaxed);
599 if ( p != static_cast<publication_record *>( pRec )) {
601 pRec->pNext.store( p, memory_model::memory_order_relaxed );
602 // Failed CAS changes p
603 } while ( !m_pHead->pNext.compare_exchange_weak( p, static_cast<publication_record *>(pRec),
604 memory_model::memory_order_release, atomics::memory_order_acquire ));
605 m_Stat.onActivatePubRecord();
610 void republish( publication_record_type* pRec )
612 if ( pRec->nState.load( memory_model::memory_order_relaxed ) != active ) {
613 // The record has been excluded from publication list. Reinsert it
618 template <class Container>
619 void try_combining( Container& owner, publication_record_type* pRec )
621 if ( m_Mutex.try_lock()) {
622 // The thread becomes a combiner
623 lock_guard l( m_Mutex, std::adopt_lock_t());
625 // The record pRec can be excluded from publication list. Re-publish it
629 assert( pRec->op( memory_model::memory_order_relaxed ) == req_Response );
632 // There is another combiner, wait while it executes our request
633 if ( !wait_for_combining( pRec )) {
634 // The thread becomes a combiner
635 lock_guard l( m_Mutex, std::adopt_lock_t());
637 // The record pRec can be excluded from publication list. Re-publish it
641 assert( pRec->op( memory_model::memory_order_relaxed ) == req_Response );
646 template <class Container>
647 void try_batch_combining( Container& owner, publication_record_type * pRec )
649 if ( m_Mutex.try_lock()) {
650 // The thread becomes a combiner
651 lock_guard l( m_Mutex, std::adopt_lock_t());
653 // The record pRec can be excluded from publication list. Re-publish it
656 batch_combining( owner );
657 assert( pRec->op( memory_model::memory_order_relaxed ) == req_Response );
660 // There is another combiner, wait while it executes our request
661 if ( !wait_for_combining( pRec )) {
662 // The thread becomes a combiner
663 lock_guard l( m_Mutex, std::adopt_lock_t());
665 // The record pRec can be excluded from publication list. Re-publish it
668 batch_combining( owner );
669 assert( pRec->op( memory_model::memory_order_relaxed ) == req_Response );
674 template <class Container>
675 void combining( Container& owner )
677 // The thread is a combiner
678 assert( !m_Mutex.try_lock());
680 unsigned int const nCurAge = m_nCount.fetch_add( 1, memory_model::memory_order_relaxed ) + 1;
682 unsigned int nEmptyPassCount = 0;
683 unsigned int nUsefulPassCount = 0;
684 for ( unsigned int nPass = 0; nPass < m_nCombinePassCount; ++nPass ) {
685 if ( combining_pass( owner, nCurAge ))
687 else if ( ++nEmptyPassCount > nUsefulPassCount )
691 m_Stat.onCombining();
692 if ( (nCurAge & m_nCompactFactor) == 0 )
693 compact_list( nCurAge );
696 template <class Container>
697 bool combining_pass( Container& owner, unsigned int nCurAge )
699 publication_record* pPrev = nullptr;
700 publication_record* p = m_pHead;
701 bool bOpDone = false;
703 switch ( p->nState.load( memory_model::memory_order_acquire )) {
705 if ( p->op() >= req_Operation ) {
706 p->nAge.store( nCurAge, memory_model::memory_order_release );
707 owner.fc_apply( static_cast<publication_record_type*>(p));
708 operation_done( *p );
713 // Only m_pHead can be inactive in the publication list
714 assert( p == m_pHead );
717 // The record should be removed
718 p = unlink_and_delete_record( pPrev, p );
721 /// ??? That is impossible
725 p = p->pNext.load( memory_model::memory_order_acquire );
730 template <class Container>
731 void batch_combining( Container& owner )
733 // The thread is a combiner
734 assert( !m_Mutex.try_lock());
736 unsigned int const nCurAge = m_nCount.fetch_add( 1, memory_model::memory_order_relaxed ) + 1;
738 for ( unsigned int nPass = 0; nPass < m_nCombinePassCount; ++nPass )
739 owner.fc_process( begin(), end());
741 combining_pass( owner, nCurAge );
742 m_Stat.onCombining();
743 if ( (nCurAge & m_nCompactFactor) == 0 )
744 compact_list( nCurAge );
747 bool wait_for_combining( publication_record_type * pRec )
749 m_waitStrategy.prepare( *pRec );
750 m_Stat.onPassiveWait();
752 while ( pRec->op( memory_model::memory_order_acquire ) != req_Response ) {
753 // The record can be excluded from publication list. Reinsert it
756 m_Stat.onPassiveWaitIteration();
758 // Wait while operation processing
759 if ( m_waitStrategy.wait( *this, *pRec ))
760 m_Stat.onWakeupByNotifying();
762 if ( m_Mutex.try_lock()) {
763 if ( pRec->op( memory_model::memory_order_acquire ) == req_Response ) {
767 // Wake up a pending threads
768 m_waitStrategy.wakeup( *this );
769 m_Stat.onPassiveWaitWakeup();
773 // The thread becomes a combiner
774 m_Stat.onPassiveToCombiner();
781 void compact_list( unsigned int const nCurAge )
783 // Thinning publication list
784 publication_record * pPrev = nullptr;
785 for ( publication_record * p = m_pHead; p; ) {
786 if ( p->nState.load( memory_model::memory_order_acquire ) == active
787 && p->nAge.load( memory_model::memory_order_acquire ) + m_nCompactFactor < nCurAge )
790 publication_record * pNext = p->pNext.load( memory_model::memory_order_acquire );
791 if ( pPrev->pNext.compare_exchange_strong( p, pNext,
792 memory_model::memory_order_release, atomics::memory_order_relaxed ))
794 p->nState.store( inactive, memory_model::memory_order_release );
796 m_Stat.onDeactivatePubRecord();
802 p = p->pNext.load( memory_model::memory_order_acquire );
805 m_Stat.onCompactPublicationList();
808 publication_record * unlink_and_delete_record( publication_record * pPrev, publication_record * p )
811 publication_record * pNext = p->pNext.load( memory_model::memory_order_acquire );
812 if ( pPrev->pNext.compare_exchange_strong( p, pNext,
813 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
815 free_publication_record( static_cast<publication_record_type *>( p ));
816 m_Stat.onDeletePubRecord();
821 m_pHead = static_cast<publication_record_type *>( p->pNext.load( memory_model::memory_order_acquire ));
822 free_publication_record( static_cast<publication_record_type *>( p ));
823 m_Stat.onDeletePubRecord();
834 template <typename PubRecord>
835 void fc_apply( PubRecord * )
840 template <typename Iterator>
841 void fc_process( Iterator, Iterator )
848 } // namespace flat_combining
849 }} // namespace cds::algo
851 #endif // #ifndef CDSLIB_ALGO_FLAT_COMBINING_KERNEL_H