3 #ifndef __CDS_CONTAINER_MSQUEUE_H
4 #define __CDS_CONTAINER_MSQUEUE_H
7 #include <cds/intrusive/msqueue.h>
8 #include <cds/container/details/base.h>
10 namespace cds { namespace container {
12 /// MSQueue related definitions
13 /** @ingroup cds_nonintrusive_helper
16 /// Internal statistics
17 template <typename Counter = cds::intrusive::msqueue::stat<>::counter_type >
18 using stat = cds::intrusive::msqueue::stat< Counter >;
20 /// Dummy internal statistics
21 typedef cds::intrusive::msqueue::empty_stat empty_stat;
23 /// MSQueue default type traits
27 typedef CDS_DEFAULT_ALLOCATOR allocator;
30 typedef cds::backoff::empty back_off;
32 /// Item counting feature; by default, disabled. Use \p cds::atomicity::item_counter to enable item counting
33 typedef atomicity::empty_item_counter item_counter;
35 /// Internal statistics (by default, disabled)
37 Possible option value are: \p msqueue::stat, \p msqueue::empty_stat (the default),
38 user-provided class that supports \p %msqueue::stat interface.
40 typedef msqueue::empty_stat stat;
42 /// C++ memory ordering model
44 Can be \p opt::v::relaxed_ordering (relaxed memory model, the default)
45 or \p opt::v::sequential_consistent (sequentially consisnent memory model).
47 typedef opt::v::relaxed_ordering memory_model;
49 /// Alignment of internal queue data. Default is \p opt::cache_line_alignment
50 enum { alignment = opt::cache_line_alignment };
53 /// Metafunction converting option list to \p msqueue::traits
55 This is a wrapper for <tt> cds::opt::make_options< type_traits, Options...> </tt>
56 Supported \p Options are:
57 - opt::allocator - allocator (like \p std::allocator) used for allocating queue nodes. Default is \ref CDS_DEFAULT_ALLOCATOR
58 - opt::back_off - back-off strategy used, default is \p cds::backoff::empty.
59 - opt::item_counter - the type of item counting feature. Default is \p cds::atomicity::empty_item_counter (item counting disabled)
60 To enable item counting use \p cds::atomicity::item_counter
61 - opt::stat - the type to gather internal statistics.
62 Possible statistics types are: \p msqueue::stat, \p msqueue::empty_stat, user-provided class that supports \p %msqueue::stat interface.
63 Default is \p %msqueue::empty_stat.
64 - opt::alignment - the alignment for internal queue data. Default is \p opt::cache_line_alignment
65 - opt::memory_model - C++ memory ordering model. Can be \p opt::v::relaxed_ordering (relaxed memory model, the default)
66 or \p opt::v::sequential_consistent (sequentially consisnent memory model).
68 Example: declare \p %MSQueue with item counting and internal statistics
70 typedef cds::container::MSQueue< cds::gc::HP, Foo,
71 typename cds::container::msqueue::make_traits<
72 cds::opt::item_counte< cds::atomicity::item_counter >,
73 cds::opt::stat< cds::intrusive::msqueue::stat<> >
78 template <typename... Options>
80 # ifdef CDS_DOXYGEN_INVOKED
81 typedef implementation_defined type; ///< Metafunction result
83 typedef typename cds::opt::make_options<
84 typename cds::opt::find_type_traits< traits, Options... >::type
89 } // namespace msqueue
93 template <typename GC, typename T, typename Traits>
98 typedef Traits traits;
100 struct node_type : public intrusive::msqueue::node< gc >
104 node_type( value_type const& val )
108 template <typename... Args>
109 node_type( Args&&... args )
110 : m_value( std::forward<Args>( args )... )
114 typedef typename traits::allocator::template rebind<node_type>::other allocator_type;
115 typedef cds::details::Allocator< node_type, allocator_type > cxx_allocator;
117 struct node_deallocator
119 void operator ()( node_type * pNode )
121 cxx_allocator().Delete( pNode );
125 struct intrusive_traits : public traits
127 typedef cds::intrusive::base_hook< cds::opt::gc<gc> > hook;
128 typedef node_deallocator disposer;
131 typedef intrusive::MSQueue< gc, node_type, intrusive_traits > type;
136 /// Michael & Scott lock-free queue
137 /** @ingroup cds_nonintrusive_queue
138 It is non-intrusive version of Michael & Scott's queue algorithm based on intrusive implementation
139 \p cds::intrusive::MSQueue.
142 - \p GC - garbage collector type: \p gc::HP, \p gc::DHP
143 - \p T is a type stored in the queue.
144 - \p Traits - queue traits, default is \p msqueue::traits. You can use \p msqueue::make_traits
145 metafunction to make your traits or just derive your traits from \p %msqueue::traits:
147 struct myTraits: public cds::container::msqueue::traits {
148 typedef cds::intrusive::msqueue::stat<> stat;
149 typedef cds::atomicity::item_counter item_counter;
151 typedef cds::container::MSQueue< cds::gc::HP, Foo, myTraits > myQueue;
153 // Equivalent make_traits example:
154 typedef cds::container::MSQueue< cds::gc::HP, Foo,
155 typename cds::container::msqueue::make_traits<
156 cds::opt::stat< cds::container::msqueue::stat<> >,
157 cds::opt::item_counter< cds::atomicity::item_counter >
162 template <typename GC, typename T, typename Traits = msqueue::traits>
164 #ifdef CDS_DOXYGEN_INVOKED
165 intrusive::MSQueue< GC, cds::intrusive::msqueue::node< T >, Traits >
167 details::make_msqueue< GC, T, Traits >::type
171 typedef details::make_msqueue< GC, T, Traits > maker;
172 typedef typename maker::type base_class;
176 /// Rebind template arguments
177 template <typename GC2, typename T2, typename Traits2>
179 typedef MSQueue< GC2, T2, Traits2> other ; ///< Rebinding result
183 typedef T value_type; ///< Value type stored in the queue
184 typedef typename base_class::gc gc; ///< Garbage collector used
185 typedef typename base_class::back_off back_off; ///< Back-off strategy used
186 typedef typename maker::allocator_type allocator_type; ///< Allocator type used for allocate/deallocate the nodes
187 typedef typename base_class::item_counter item_counter; ///< Item counting policy used
188 typedef typename base_class::stat stat; ///< Internal statistics policy used
189 typedef typename base_class::memory_model memory_model; ///< Memory ordering. See cds::opt::memory_model option
193 typedef typename maker::node_type node_type; ///< queue node type (derived from \p intrusive::msqueue::node)
195 typedef typename maker::cxx_allocator cxx_allocator;
196 typedef typename maker::node_deallocator node_deallocator; // deallocate node
197 typedef typename base_class::node_traits node_traits;
202 static node_type * alloc_node()
204 return cxx_allocator().New();
206 static node_type * alloc_node( value_type const& val )
208 return cxx_allocator().New( val );
210 template <typename... Args>
211 static node_type * alloc_node_move( Args&&... args )
213 return cxx_allocator().MoveNew( std::forward<Args>( args )... );
215 static void free_node( node_type * p )
217 node_deallocator()( p );
220 struct node_disposer {
221 void operator()( node_type * pNode )
226 typedef std::unique_ptr< node_type, node_disposer > scoped_node_ptr;
230 /// Initializes empty queue
234 /// Destructor clears the queue
238 /// Enqueues \p val value into the queue.
240 The function makes queue node in dynamic memory calling copy constructor for \p val
241 and then it calls intrusive::MSQueue::enqueue.
242 Returns \p true if success, \p false otherwise.
244 bool enqueue( value_type const& val )
246 scoped_node_ptr p( alloc_node(val) );
247 if ( base_class::enqueue( *p ) ) {
254 /// Enqueues \p data to queue using a functor
256 \p Func is a functor called to create node.
257 The functor \p f takes one argument - a reference to a new node of type \ref value_type:
259 cds:container::MSQueue< cds::gc::HP, Foo > myQueue;
261 myQueue.enqueue_with( [&bar]( Foo& dest ) { dest = bar; } );
264 template <typename Func>
265 bool enqueue_with( Func f )
267 scoped_node_ptr p( alloc_node() );
269 if ( base_class::enqueue( *p )) {
276 /// Enqueues data of type \ref value_type constructed from <tt>std::forward<Args>(args)...</tt>
277 template <typename... Args>
278 bool emplace( Args&&... args )
280 scoped_node_ptr p( alloc_node_move( std::forward<Args>( args )... ) );
281 if ( base_class::enqueue( *p ) ) {
288 /// Synonym for \p enqueue() function
289 bool push( value_type const& val )
291 return enqueue( val );
294 /// Synonym for \p enqueue_with() function
295 template <typename Func>
296 bool push_with( Func f )
298 return enqueue_with( f );
301 /// Dequeues a value from the queue
303 If queue is not empty, the function returns \p true, \p dest contains copy of
304 dequeued value. The assignment operator for type \ref value_type is invoked.
305 If queue is empty, the function returns \p false, \p dest is unchanged.
307 bool dequeue( value_type& dest )
309 return dequeue_with( [&dest]( value_type& src ) { dest = src; } );
312 /// Dequeues a value using a functor
314 \p Func is a functor called to copy dequeued value.
315 The functor takes one argument - a reference to removed node:
317 cds:container::MSQueue< cds::gc::HP, Foo > myQueue;
319 myQueue.dequeue_with( [&bar]( Foo& src ) { bar = std::move( src );});
321 The functor is called only if the queue is not empty.
323 template <typename Func>
324 bool dequeue_with( Func f )
326 typename base_class::dequeue_result res;
327 if ( base_class::do_dequeue( res )) {
328 f( node_traits::to_value_ptr( *res.pNext )->m_value );
329 base_class::dispose_result( res );
335 /// Synonym for \p dequeue() function
336 bool pop( value_type& dest )
338 return dequeue( dest );
341 /// Synonym for \p dequeue_with() function
342 template <typename Func>
343 bool pop_with( Func f )
345 return dequeue_with( f );
350 The function repeatedly calls \ref dequeue until it returns \p nullptr.
357 /// Checks if the queue is empty
360 return base_class::empty();
363 /// Returns queue's item count (see \ref intrusive::MSQueue::size for explanation)
366 return base_class::size();
369 /// Returns reference to internal statistics
370 const stat& statistics() const
372 return base_class::statistics();
376 }} // namespace cds::container
378 #endif // #ifndef __CDS_CONTAINER_MSQUEUE_H