--- /dev/null
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
+
+ Source code repo: http://github.com/khizmax/libcds/
+ Download: http://sourceforge.net/projects/libcds/files/
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CDSLIB_CONTAINER_FCQUEUE_H
+#define CDSLIB_CONTAINER_FCQUEUE_H
+
+#include <cds/algo/flat_combining.h>
+#include <cds/algo/elimination_opt.h>
+#include <queue>
+
+namespace cds { namespace container {
+
+ /// FCQueue related definitions
+ /** @ingroup cds_nonintrusive_helper
+ */
+ namespace fcqueue {
+
+ /// FCQueue 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_nEnqueue ; ///< Count of enqueue operations
+ counter_type m_nEnqMove ; ///< Count of enqueue operations with move semantics
+ counter_type m_nDequeue ; ///< Count of success dequeue operations
+ counter_type m_nFailedDeq ; ///< Count of failed dequeue operations (pop from empty queue)
+ counter_type m_nCollided ; ///< How many pairs of enqueue/dequeue were collided, if elimination is enabled
+
+ //@cond
+ void onEnqueue() { ++m_nEnqueue; }
+ void onEnqMove() { ++m_nEnqMove; }
+ void onDequeue( bool bFailed ) { if ( bFailed ) ++m_nFailedDeq; else ++m_nDequeue; }
+ void onCollide() { ++m_nCollided; }
+ //@endcond
+ };
+
+ /// FCQueue dummy statistics, no overhead
+ struct empty_stat: public cds::algo::flat_combining::empty_stat
+ {
+ //@cond
+ void onEnqueue() {}
+ void onEnqMove() {}
+ void onDequeue(bool) {}
+ void onCollide() {}
+ //@endcond
+ };
+
+ /// FCQueue type traits
+ struct traits: public cds::algo::flat_combining::traits
+ {
+ typedef empty_stat stat; ///< Internal statistics
+ static constexpr const bool enable_elimination = false; ///< Enable \ref cds_elimination_description "elimination"
+ };
+
+ /// Metafunction converting option list to traits
+ /**
+ \p Options are:
+ - any \p cds::algo::flat_combining::make_traits options
+ - \p opt::stat - internal statistics, possible type: \p fcqueue::stat, \p fcqueue::empty_stat (the default)
+ - \p opt::enable_elimination - enable/disable operation \ref cds_elimination_description "elimination"
+ By default, the elimination is disabled. For queue, the elimination is possible if the queue
+ is empty.
+ */
+ template <typename... Options>
+ 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< traits, Options... >::type
+ ,Options...
+ >::type type;
+# endif
+ };
+
+ } // namespace fcqueue
+
+ /// Flat-combining queue
+ /**
+ @ingroup cds_nonintrusive_queue
+ @ingroup cds_flat_combining_container
+
+ \ref cds_flat_combining_description "Flat combining" sequential queue.
+ The class can be considered as a concurrent FC-based wrapper for \p std::queue.
+
+ Template parameters:
+ - \p T - a value type stored in the queue
+ - \p Queue - sequential queue implementation, default is \p std::queue<T>
+ - \p Trats - type traits of flat combining, default is \p fcqueue::traits.
+ \p fcqueue::make_traits metafunction can be used to construct \p %fcqueue::traits specialization.
+ */
+ template <typename T,
+ class Queue = std::queue<T>,
+ typename Traits = fcqueue::traits
+ >
+ class FCQueue
+#ifndef CDS_DOXYGEN_INVOKED
+ : public cds::algo::flat_combining::container
+#endif
+ {
+ public:
+ typedef T value_type; ///< Value type
+ typedef Queue queue_type; ///< Sequential queue class
+ typedef Traits traits; ///< Queue type traits
+
+ typedef typename traits::stat stat; ///< Internal statistics type
+ static constexpr const bool c_bEliminationEnabled = traits::enable_elimination; ///< \p true if elimination is enabled
+
+ protected:
+ //@cond
+ /// Queue operation IDs
+ enum fc_operation {
+ op_enq = cds::algo::flat_combining::req_Operation, ///< Enqueue
+ op_enq_move, ///< Enqueue (move semantics)
+ op_deq, ///< Dequeue
+ op_clear ///< Clear
+ };
+
+ /// Flat combining publication list record
+ struct fc_record: public cds::algo::flat_combining::publication_record
+ {
+ union {
+ value_type const * pValEnq; ///< Value to enqueue
+ value_type * pValDeq; ///< Dequeue destination
+ };
+ bool bEmpty; ///< \p true if the queue is empty
+ };
+ //@endcond
+
+ /// Flat combining kernel
+ typedef cds::algo::flat_combining::kernel< fc_record, traits > fc_kernel;
+
+ protected:
+ //@cond
+ mutable fc_kernel m_FlatCombining;
+ queue_type m_Queue;
+ //@endcond
+
+ public:
+ /// Initializes empty queue object
+ FCQueue()
+ {}
+
+ /// Initializes empty queue object and gives flat combining parameters
+ FCQueue(
+ 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 at the end of the queue
+ /**
+ The content of the new element initialized to a copy of \p val.
+
+ The function always returns \p true
+ */
+ bool enqueue( value_type const& val )
+ {
+ auto pRec = m_FlatCombining.acquire_record();
+ pRec->pValEnq = &val;
+
+ constexpr_if ( c_bEliminationEnabled )
+ m_FlatCombining.batch_combine( op_enq, pRec, *this );
+ else
+ m_FlatCombining.combine( op_enq, pRec, *this );
+
+ assert( pRec->is_done());
+ m_FlatCombining.release_record( pRec );
+ m_FlatCombining.internal_statistics().onEnqueue();
+ return true;
+ }
+
+ /// Inserts a new element at the end of the queue (a synonym for \ref enqueue)
+ bool push( value_type const& val )
+ {
+ return enqueue( val );
+ }
+
+ /// Inserts a new element at the end of the queue (move semantics)
+ /**
+ \p val is moved to inserted element
+ */
+ bool enqueue( value_type&& val )
+ {
+ auto pRec = m_FlatCombining.acquire_record();
+ pRec->pValEnq = &val;
+
+ constexpr_if ( c_bEliminationEnabled )
+ m_FlatCombining.batch_combine( op_enq_move, pRec, *this );
+ else
+ m_FlatCombining.combine( op_enq_move, pRec, *this );
+
+ assert( pRec->is_done());
+ m_FlatCombining.release_record( pRec );
+
+ m_FlatCombining.internal_statistics().onEnqMove();
+ return true;
+ }
+
+ /// Inserts a new element at the end of the queue (move semantics, synonym for \p enqueue)
+ bool push( value_type&& val )
+ {
+ return enqueue( val );
+ }
+
+ /// Removes the next element from the queue
+ /**
+ \p val takes a copy of the element
+ */
+ bool dequeue( value_type& val )
+ {
+ auto pRec = m_FlatCombining.acquire_record();
+ pRec->pValDeq = &val;
+
+ constexpr_if ( c_bEliminationEnabled )
+ m_FlatCombining.batch_combine( op_deq, pRec, *this );
+ else
+ m_FlatCombining.combine( op_deq, pRec, *this );
+
+ assert( pRec->is_done());
+ m_FlatCombining.release_record( pRec );
+
+ m_FlatCombining.internal_statistics().onDequeue( pRec->bEmpty );
+ return !pRec->bEmpty;
+ }
+
+ /// Removes the next element from the queue (a synonym for \ref dequeue)
+ bool pop( value_type& val )
+ {
+ return dequeue( val );
+ }
+
+ /// Clears the queue
+ void clear()
+ {
+ auto pRec = m_FlatCombining.acquire_record();
+
+ constexpr_if ( c_bEliminationEnabled )
+ m_FlatCombining.batch_combine( op_clear, pRec, *this );
+ else
+ m_FlatCombining.combine( op_clear, pRec, *this );
+
+ assert( pRec->is_done());
+ m_FlatCombining.release_record( pRec );
+ }
+
+ /// Exclusive access to underlying queue object
+ /**
+ The functor \p f can do any operation with underlying \p queue_type in exclusive mode.
+ For example, you can iterate over the queue.
+ \p Func signature is:
+ \code
+ void f( queue_type& queue );
+ \endcode
+ */
+ template <typename Func>
+ void apply( Func f )
+ {
+ auto& queue = m_Queue;
+ m_FlatCombining.invoke_exclusive( [&queue, &f]() { f( queue ); } );
+ }
+
+ /// Exclusive access to underlying queue object
+ /**
+ The functor \p f can do any operation with underlying \p queue_type in exclusive mode.
+ For example, you can iterate over the queue.
+ \p Func signature is:
+ \code
+ void f( queue_type const& queue );
+ \endcode
+ */
+ template <typename Func>
+ void apply( Func f ) const
+ {
+ auto const& queue = m_Queue;
+ m_FlatCombining.invoke_exclusive( [&queue, &f]() { f( queue ); } );
+ }
+
+ /// Returns the number of elements in the queue.
+ /**
+ Note that <tt>size() == 0</tt> is 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_Queue.size();
+ }
+
+ /// Checks if the queue is empty
+ /**
+ If the combining is in process the function waits while combining done.
+ */
+ bool empty() const
+ {
+ bool bRet = false;
+ auto const& queue = m_Queue;
+ m_FlatCombining.invoke_exclusive( [&queue, &bRet]() { bRet = queue.empty(); } );
+ return bRet;
+ }
+
+ /// Internal statistics
+ stat const& statistics() const
+ {
+ return m_FlatCombining.statistics();
+ }
+
+ public: // flat combining cooperation, not for direct use!
+ //@cond
+ /// Flat combining supporting function. Do not call it directly!
+ /**
+ 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 queue should perform an action recorded in \p pRec.
+ */
+ void fc_apply( fc_record * pRec )
+ {
+ assert( pRec );
+
+ switch ( pRec->op()) {
+ case op_enq:
+ assert( pRec->pValEnq );
+ m_Queue.push( *(pRec->pValEnq ));
+ break;
+ case op_enq_move:
+ assert( pRec->pValEnq );
+ m_Queue.push( std::move( *(pRec->pValEnq )));
+ break;
+ case op_deq:
+ assert( pRec->pValDeq );
+ pRec->bEmpty = m_Queue.empty();
+ if ( !pRec->bEmpty ) {
+ *(pRec->pValDeq) = std::move( m_Queue.front());
+ m_Queue.pop();
+ }
+ break;
+ case op_clear:
+ while ( !m_Queue.empty())
+ m_Queue.pop();
+ break;
+ default:
+ assert(false);
+ break;
+ }
+ }
+
+ /// Batch-processing flat combining
+ void fc_process( typename fc_kernel::iterator itBegin, typename fc_kernel::iterator itEnd )
+ {
+ typedef typename fc_kernel::iterator fc_iterator;
+
+ for ( fc_iterator it = itBegin, itPrev = itEnd; it != itEnd; ++it ) {
+ switch ( it->op( atomics::memory_order_acquire )) {
+ case op_enq:
+ case op_enq_move:
+ case op_deq:
+ if ( m_Queue.empty()) {
+ if ( itPrev != itEnd && collide( *itPrev, *it ))
+ itPrev = itEnd;
+ else
+ itPrev = it;
+ }
+ break;
+ }
+ }
+ }
+ //@endcond
+
+ private:
+ //@cond
+ bool collide( fc_record& rec1, fc_record& rec2 )
+ {
+ switch ( rec1.op()) {
+ case op_enq:
+ if ( rec2.op() == op_deq ) {
+ assert(rec1.pValEnq);
+ assert(rec2.pValDeq);
+ *rec2.pValDeq = *rec1.pValEnq;
+ rec2.bEmpty = false;
+ goto collided;
+ }
+ break;
+ case op_enq_move:
+ if ( rec2.op() == op_deq ) {
+ assert(rec1.pValEnq);
+ assert(rec2.pValDeq);
+ *rec2.pValDeq = std::move( *rec1.pValEnq );
+ rec2.bEmpty = false;
+ goto collided;
+ }
+ break;
+ case op_deq:
+ switch ( rec2.op()) {
+ case op_enq:
+ case op_enq_move:
+ return collide( rec2, rec1 );
+ }
+ }
+ return false;
+
+ collided:
+ m_FlatCombining.operation_done( rec1 );
+ m_FlatCombining.operation_done( rec2 );
+ m_FlatCombining.internal_statistics().onCollide();
+ return true;
+ }
+ //@endcond
+
+ };
+}} // namespace cds::container
+
+#endif // #ifndef CDSLIB_CONTAINER_FCQUEUE_H
projects / c11concurrency-benchmarks.git / blobdiff