--- /dev/null
+//$$CDS-header$$
+
+#ifndef __CDS_CONTAINER_FCPRIORITY_QUEUE_H
+#define __CDS_CONTAINER_FCPRIORITY_QUEUE_H
+
+#include <cds/algo/flat_combining.h>
+#include <cds/algo/elimination_opt.h>
+#include <queue>
+
+namespace cds { namespace container {
+
+ /// FCPriorityQueue related definitions
+ /** @ingroup cds_nonintrusive_helper
+ */
+ namespace fcpqueue {
+
+ /// FCPriorityQueue internal statistics
+ template <typename Counter = cds::atomicity::event_counter >
+ struct stat: public cds::algo::flat_combining::stat<Counter>
+ {
+ typedef cds::algo::flat_combining::stat<Counter> flat_combining_stat; ///< Flat-combining statistics
+ typedef typename flat_combining_stat::counter_type counter_type; ///< Counter type
+
+ counter_type m_nPush ; ///< Count of push operations
+ counter_type m_nPushMove ; ///< Count of push operations with move semantics
+ counter_type m_nPop ; ///< Count of success pop operations
+ counter_type m_nFailedPop; ///< Count of failed pop operations (pop from empty queue)
+
+ //@cond
+ void onPush() { ++m_nPush; }
+ void onPushMove() { ++m_nPushMove; }
+ void onPop( bool bFailed ) { if ( bFailed ) ++m_nFailedPop; else ++m_nPop; }
+ //@endcond
+ };
+
+ /// FCPriorityQueue dummy statistics, no overhead
+ struct empty_stat: public cds::algo::flat_combining::empty_stat
+ {
+ //@cond
+ void onPush() {}
+ void onPushMove() {}
+ void onPop(bool) {}
+ //@endcond
+ };
+
+ /// FCPriorityQueue type traits
+ struct type_traits: public cds::algo::flat_combining::type_traits
+ {
+ typedef empty_stat stat; ///< Internal statistics
+ };
+
+ /// Metafunction converting option list to traits
+ /**
+ This is a wrapper for <tt> cds::opt::make_options< type_traits, Options...> </tt>
+ \p Options are:
+ - \p opt::lock_type - mutex type, default is \p cds::lock::Spin
+ - \p opt::back_off - back-off strategy, defalt is \p cds::backoff::Default
+ - \p opt::allocator - allocator type, default is \ref CDS_DEFAULT_ALLOCATOR
+ - \p opt::stat - internal statistics, possible type: \ref stat, \ref empty_stat (the default)
+ - \p opt::memory_model - C++ memory ordering model.
+ List of all available memory ordering see opt::memory_model.
+ Default is cds::opt::v:relaxed_ordering
+ */
+ template <CDS_DECL_OPTIONS7>
+ struct make_traits {
+# ifdef CDS_DOXYGEN_INVOKED
+ typedef implementation_defined type ; ///< Metafunction result
+# else
+ typedef typename cds::opt::make_options<
+ typename cds::opt::find_type_traits< type_traits, CDS_OPTIONS7 >::type
+ ,CDS_OPTIONS7
+ >::type type;
+# endif
+ };
+
+ } // namespace fcpqueue
+
+ /// Flat-combining priority queue
+ /**
+ @ingroup cds_nonintrusive_priority_queue
+ @ingroup cds_flat_combining_container
+
+ \ref cds_flat_combining_description "Flat combining" sequential priority queue.
+ The class can be considered as a concurrent FC-based wrapper for \p std::priority_queue.
+
+ Template parameters:
+ - \p T - a value type stored in the queue
+ - \p PriorityQueue - sequential priority queue implementation, default is \p std::priority_queue<T>
+ - \p Traits - type traits of flat combining, default is \p fcpqueue::type_traits.
+ \p fcpqueue::make_traits metafunction can be used to construct specialized \p %type_traits
+ */
+ template <typename T,
+ class PriorityQueue = std::priority_queue<T>,
+ typename Traits = fcpqueue::type_traits
+ >
+ class FCPriorityQueue
+#ifndef CDS_DOXYGEN_INVOKED
+ : public cds::algo::flat_combining::container
+#endif
+ {
+ public:
+ typedef T value_type; ///< Value type
+ typedef PriorityQueue priority_queue_type; ///< Sequential priority queue class
+ typedef Traits type_traits; ///< Priority queue type traits
+
+ typedef typename type_traits::stat stat; ///< Internal statistics type
+
+ protected:
+ //@cond
+ // Priority queue operation IDs
+ enum fc_operation {
+ op_push = cds::algo::flat_combining::req_Operation,
+ op_push_move,
+ op_pop,
+ op_clear
+ };
+
+ // Flat combining publication list record
+ struct fc_record: public cds::algo::flat_combining::publication_record
+ {
+ union {
+ value_type const * pValPush; // Value to push
+ value_type * pValPop; // Pop destination
+ };
+ bool bEmpty; // true if the queue is empty
+ };
+ //@endcond
+
+ /// Flat combining kernel
+ typedef cds::algo::flat_combining::kernel< fc_record, type_traits > fc_kernel;
+
+ protected:
+ //@cond
+ fc_kernel m_FlatCombining;
+ priority_queue_type m_PQueue;
+ //@endcond
+
+ public:
+ /// Initializes empty priority queue object
+ FCPriorityQueue()
+ {}
+
+ /// Initializes empty priority queue object and gives flat combining parameters
+ FCPriorityQueue(
+ unsigned int nCompactFactor ///< Flat combining: publication list compacting factor
+ ,unsigned int nCombinePassCount ///< Flat combining: number of combining passes for combiner thread
+ )
+ : m_FlatCombining( nCompactFactor, nCombinePassCount )
+ {}
+
+ /// Inserts a new element in the priority queue
+ /**
+ The function always returns \p true
+ */
+ bool push(
+ value_type const& val ///< Value to be copied to inserted element
+ )
+ {
+ fc_record * pRec = m_FlatCombining.acquire_record();
+ pRec->pValPush = &val;
+
+ m_FlatCombining.combine( op_push, pRec, *this );
+
+ assert( pRec->is_done() );
+ m_FlatCombining.release_record( pRec );
+ m_FlatCombining.internal_statistics().onPush();
+ return true;
+ }
+
+# ifdef CDS_MOVE_SEMANTICS_SUPPORT
+ /// Inserts a new element in the priority queue (move semantics)
+ /**
+ The function always returns \p true
+ */
+ bool push(
+ value_type&& val ///< Value to be moved to inserted element
+ )
+ {
+ fc_record * pRec = m_FlatCombining.acquire_record();
+ pRec->pValPush = &val;
+
+ m_FlatCombining.combine( op_push_move, pRec, *this );
+
+ assert( pRec->is_done() );
+ m_FlatCombining.release_record( pRec );
+ m_FlatCombining.internal_statistics().onPushMove();
+ return true;
+ }
+# endif
+
+ /// Removes the top element from priority queue
+ /**
+ The function returns \p false if the queue is empty, \p true otherwise.
+ If the queue is empty \p val is not changed.
+ */
+ bool pop(
+ value_type& val ///< Target to be received the copy of top element
+ )
+ {
+ fc_record * pRec = m_FlatCombining.acquire_record();
+ pRec->pValPop = &val;
+
+ m_FlatCombining.combine( op_pop, pRec, *this );
+
+ assert( pRec->is_done() );
+ m_FlatCombining.release_record( pRec );
+ m_FlatCombining.internal_statistics().onPop( pRec->bEmpty );
+ return !pRec->bEmpty;
+ }
+
+ /// Clears the priority queue
+ void clear()
+ {
+ fc_record * pRec = m_FlatCombining.acquire_record();
+
+ m_FlatCombining.combine( op_clear, pRec, *this );
+
+ assert( pRec->is_done() );
+ m_FlatCombining.release_record( pRec );
+ }
+
+ /// Returns the number of elements in the priority queue.
+ /**
+ Note that <tt>size() == 0</tt> does not mean that the queue is empty because
+ combining record can be in process.
+ To check emptiness use \ref empty function.
+ */
+ size_t size() const
+ {
+ return m_PQueue.size();
+ }
+
+ /// Checks if the priority queue is empty
+ /**
+ If the combining is in process the function waits while combining done.
+ */
+ bool empty() const
+ {
+ m_FlatCombining.wait_while_combining();
+ return m_PQueue.empty();
+ }
+
+ /// Internal statistics
+ stat const& statistics() const
+ {
+ return m_FlatCombining.statistics();
+ }
+
+ public: // flat combining cooperation, not for direct use!
+ //@cond
+ /*
+ The function is called by \ref cds::algo::flat_combining::kernel "flat combining kernel"
+ object if the current thread becomes a combiner. Invocation of the function means that
+ the priority queue should perform an action recorded in \p pRec.
+ */
+ void fc_apply( fc_record * pRec )
+ {
+ assert( pRec );
+
+ switch ( pRec->op() ) {
+ case op_push:
+ assert( pRec->pValPush );
+ m_PQueue.push( *(pRec->pValPush) );
+ break;
+# ifdef CDS_MOVE_SEMANTICS_SUPPORT
+ case op_push_move:
+ assert( pRec->pValPush );
+ m_PQueue.push( std::move( *(pRec->pValPush )) );
+ break;
+# endif
+ case op_pop:
+ assert( pRec->pValPop );
+ pRec->bEmpty = m_PQueue.empty();
+ if ( !pRec->bEmpty ) {
+ *(pRec->pValPop) = m_PQueue.top();
+ m_PQueue.pop();
+ }
+ break;
+ case op_clear:
+ while ( !m_PQueue.empty() )
+ m_PQueue.pop();
+ break;
+ default:
+ assert(false);
+ break;
+ }
+ }
+ //@endcond
+ };
+
+}} // namespace cds::container
+
+#endif // #ifndef __CDS_CONTAINER_FCPRIORITY_QUEUE_H
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