-//$$CDS-header$$
-
-#ifndef __CDS_CONTAINER_MICHAEL_MAP_RCU_H
-#define __CDS_CONTAINER_MICHAEL_MAP_RCU_H
-
-#include <cds/container/michael_map_base.h>
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2016
+
+ 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_MICHAEL_MAP_RCU_H
+#define CDSLIB_CONTAINER_MICHAEL_MAP_RCU_H
+
+#include <cds/container/details/michael_map_base.h>
#include <cds/details/allocator.h>
namespace cds { namespace container {
Template parameters are:
- \p RCU - one of \ref cds_urcu_gc "RCU type"
- - \p OrderedList - ordered key-value list implementation used as bucket for hash map, for example, MichaelKVList.
+ - \p OrderedList - ordered key-value list implementation used as bucket for hash map, for example, \p MichaelKVList.
The ordered list implementation specifies the \p Key and \p Value types stored in the hash-map, the reclamation
schema \p GC used by hash-map, the comparison functor for the type \p Key and other features specific for
the ordered list.
- - \p Traits - type traits. See michael_map::type_traits for explanation.
-
- Instead of defining \p Traits struct you may use option-based syntax with \p michael_map::make_traits metafunction
- (this metafunction is a synonym for michael_set::make_traits).
- For \p michael_map::make_traits the following option may be used:
- - opt::hash - mandatory option, specifies hash functor.
- - opt::item_counter - optional, specifies item counting policy. See michael_map::type_traits for explanation.
- - opt::allocator - optional, bucket table allocator. Default is \ref CDS_DEFAULT_ALLOCATOR.
+ - \p Traits - map traits, default is \p michael_map::traits.
+ Instead of defining \p Traits struct you may use option-based syntax with \p michael_map::make_traits metafunction
- Many of the class function take a key argument of type \p K that in general is not \ref key_type.
+ Many of the class function take a key argument of type \p K that in general is not \p key_type.
\p key_type and an argument of template type \p K must meet the following requirements:
- \p key_type should be constructible from value of type \p K;
- the hash functor should be able to calculate correct hash value from argument \p key of type \p K:
class RCU,
class OrderedList,
#ifdef CDS_DOXYGEN_INVOKED
- class Traits = michael_map::type_traits
+ class Traits = michael_map::traits
#else
class Traits
#endif
class MichaelHashMap< cds::urcu::gc< RCU >, OrderedList, Traits >
{
public:
- typedef OrderedList bucket_type ; ///< type of ordered list used as a bucket implementation
- typedef Traits options ; ///< Traits template parameters
-
- typedef typename bucket_type::key_type key_type ; ///< key type
- typedef typename bucket_type::mapped_type mapped_type ; ///< value type
- typedef typename bucket_type::value_type value_type ; ///< key/value pair stored in the list
-
- typedef cds::urcu::gc< RCU > gc ; ///< RCU used as garbage collector
- typedef typename bucket_type::key_comparator key_comparator ; ///< key comparison functor
+ typedef cds::urcu::gc< RCU > gc; ///< RCU used as garbage collector
+ typedef OrderedList ordered_list; ///< type of ordered list used as a bucket implementation
+ typedef Traits traits; ///< Map traits
+
+ typedef typename ordered_list::key_type key_type; ///< key type
+ typedef typename ordered_list::mapped_type mapped_type; ///< value type
+ typedef typename ordered_list::value_type value_type; ///< key/value pair stored in the list
+ typedef typename ordered_list::key_comparator key_comparator;///< key comparison functor
+#ifdef CDS_DOXYGEN_INVOKED
+ typedef typename ordered_list::stat stat; ///< Internal statistics
+ typedef typename ordered_list::exempt_ptr exempt_ptr; ///< pointer to extracted node
+ /// Type of \p get() member function return value
+ typedef typename ordered_list::raw_ptr raw_ptr;
+ typedef typename ordered_list::rcu_lock rcu_lock; ///< RCU scoped lock
+#endif
/// Hash functor for \ref key_type and all its derivatives that you use
- typedef typename cds::opt::v::hash_selector< typename options::hash >::type hash;
- typedef typename options::item_counter item_counter ; ///< Item counter type
+ typedef typename cds::opt::v::hash_selector< typename traits::hash >::type hash;
+ typedef typename traits::item_counter item_counter; ///< Item counter type
+ typedef typename traits::allocator allocator; ///< Bucket table allocator
- /// Bucket table allocator
- typedef cds::details::Allocator< bucket_type, typename options::allocator > bucket_table_allocator;
-
- typedef typename bucket_type::rcu_lock rcu_lock ; ///< RCU scoped lock
- typedef typename bucket_type::exempt_ptr exempt_ptr ; ///< pointer to extracted node
/// Group of \p extract_xxx functions require external locking if underlying ordered list requires that
- static CDS_CONSTEXPR_CONST bool c_bExtractLockExternal = bucket_type::c_bExtractLockExternal;
+ static CDS_CONSTEXPR const bool c_bExtractLockExternal = ordered_list::c_bExtractLockExternal;
+
+ // GC and OrderedList::gc must be the same
+ static_assert(std::is_same<gc, typename ordered_list::gc>::value, "GC and OrderedList::gc must be the same");
+
+ // atomicity::empty_item_counter is not allowed as a item counter
+ static_assert(!std::is_same<item_counter, cds::atomicity::empty_item_counter>::value,
+ "cds::atomicity::empty_item_counter is not allowed as a item counter");
protected:
- item_counter m_ItemCounter ; ///< Item counter
- hash m_HashFunctor ; ///< Hash functor
+ //@cond
+ typedef typename ordered_list::template select_stat_wrapper< typename ordered_list::stat > bucket_stat;
- bucket_type * m_Buckets ; ///< bucket table
+ typedef typename ordered_list::template rebind_traits<
+ cds::opt::item_counter< cds::atomicity::empty_item_counter >
+ , cds::opt::stat< typename bucket_stat::wrapped_stat >
+ >::type internal_bucket_type;
- private:
+ /// Bucket table allocator
+ typedef typename allocator::template rebind< internal_bucket_type >::other bucket_table_allocator;
+ //@endcond
+
+ public:
//@cond
- const size_t m_nHashBitmask;
+ typedef typename bucket_stat::stat stat;
+ typedef typename internal_bucket_type::exempt_ptr exempt_ptr;
+ typedef typename internal_bucket_type::raw_ptr raw_ptr;
+ typedef typename internal_bucket_type::rcu_lock rcu_lock;
//@endcond
protected:
- /// Calculates hash value of \p key
- template <typename Q>
- size_t hash_value( Q const& key ) const
- {
- return m_HashFunctor( key ) & m_nHashBitmask;
- }
+ //@cond
+ const size_t m_nHashBitmask;
+ item_counter m_ItemCounter; ///< Item counter
+ hash m_HashFunctor; ///< Hash functor
+ internal_bucket_type * m_Buckets; ///< bucket table
+ stat m_Stat; ///< Internal statistics
+ //@endcond
- /// Returns the bucket (ordered list) for \p key
- //@{
- template <typename Q>
- bucket_type& bucket( Q const& key )
- {
- return m_Buckets[ hash_value( key ) ];
- }
- template <typename Q>
- bucket_type const& bucket( Q const& key ) const
- {
- return m_Buckets[ hash_value( key ) ];
- }
- //@}
protected:
- /// Forward iterator
- /**
- \p IsConst - constness boolean flag
-
- The forward iterator for Michael's map is based on \p OrderedList forward iterator and has the following features:
- - it has no post-increment operator, only pre-increment
- - it iterates items in unordered fashion
- - The iterator cannot be moved across thread boundary since it may contain GC's guard that is thread-private GC data.
- - Iterator ensures thread-safety even if you delete the item that iterator points to. However, in case of concurrent
- deleting operations it is no guarantee that you iterate all item in the map.
-
- Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator for the concurrent container
- for debug purpose only.
- */
+ //@cond
template <bool IsConst>
- class iterator_type: private cds::intrusive::michael_set::details::iterator< bucket_type, IsConst >
+ class iterator_type: private cds::intrusive::michael_set::details::iterator< internal_bucket_type, IsConst >
{
- //@cond
- typedef cds::intrusive::michael_set::details::iterator< bucket_type, IsConst > base_class;
+ typedef cds::intrusive::michael_set::details::iterator< internal_bucket_type, IsConst > base_class;
friend class MichaelHashMap;
- //@endcond
protected:
- //@cond
- //typedef typename base_class::bucket_type bucket_type;
typedef typename base_class::bucket_ptr bucket_ptr;
typedef typename base_class::list_iterator list_iterator;
- //typedef typename bucket_type::key_type key_type;
- //@endcond
-
public:
/// Value pointer type (const for const_iterator)
typedef typename cds::details::make_const_type<typename MichaelHashMap::mapped_type, IsConst>::pointer value_ptr;
typedef typename cds::details::make_const_type<typename MichaelHashMap::value_type, IsConst>::reference pair_ref;
protected:
- //@cond
iterator_type( list_iterator const& it, bucket_ptr pFirst, bucket_ptr pLast )
: base_class( it, pFirst, pLast )
{}
- //@endcond
public:
/// Default ctor
/// Dereference operator
pair_ptr operator ->() const
{
- assert( base_class::m_pCurBucket != null_ptr<bucket_ptr>() );
+ assert( base_class::m_pCurBucket != nullptr );
return base_class::m_itList.operator ->();
}
/// Dereference operator
pair_ref operator *() const
{
- assert( base_class::m_pCurBucket != null_ptr<bucket_ptr>() );
+ assert( base_class::m_pCurBucket != nullptr );
return base_class::m_itList.operator *();
}
return !( *this == i );
}
};
+ //@endcond
public:
+ ///@name Forward iterators (thread-safe under RCU lock)
+ //@{
+
/// Forward iterator
+ /**
+ The forward iterator for Michael's map is based on \p OrderedList forward iterator and has some features:
+ - it has no post-increment operator
+ - it iterates items in unordered fashion
+
+ You may safely use iterators in multi-threaded environment only under RCU lock.
+ Otherwise, a crash is possible if another thread deletes the element the iterator points to.
+
+ The iterator interface:
+ \code
+ class iterator {
+ public:
+ // Default constructor
+ iterator();
+
+ // Copy construtor
+ iterator( iterator const& src );
+
+ // Dereference operator
+ value_type * operator ->() const;
+
+ // Dereference operator
+ value_type& operator *() const;
+
+ // Preincrement operator
+ iterator& operator ++();
+
+ // Assignment operator
+ iterator& operator = (iterator const& src);
+
+ // Equality operators
+ bool operator ==(iterator const& i ) const;
+ bool operator !=(iterator const& i ) const;
+ };
+ \endcode
+ */
typedef iterator_type< false > iterator;
/// Const forward iterator
}
/// Returns a forward const iterator addressing the first element in a map
- //@{
const_iterator begin() const
{
return get_const_begin();
}
- const_iterator cbegin()
+
+ /// Returns a forward const iterator addressing the first element in a map
+ const_iterator cbegin() const
{
return get_const_begin();
}
- //@}
/// Returns an const iterator that addresses the location succeeding the last element in a map
- //@{
const_iterator end() const
{
return get_const_end();
}
- const_iterator cend()
- {
- return get_const_end();
- }
- //@}
- private:
- //@cond
- const_iterator get_const_begin() const
- {
- return const_iterator( const_cast<bucket_type const&>(m_Buckets[0]).begin(), m_Buckets, m_Buckets + bucket_count() );
- }
- const_iterator get_const_end() const
+ /// Returns an const iterator that addresses the location succeeding the last element in a map
+ const_iterator cend() const
{
- return const_iterator( const_cast<bucket_type const&>(m_Buckets[bucket_count() - 1]).end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count() );
+ return get_const_end();
}
- //@endcond
+ //@}
public:
/// Initializes the map
size_t nMaxItemCount, ///< estimation of max item count in the hash map
size_t nLoadFactor ///< load factor: estimation of max number of items in the bucket
) : m_nHashBitmask( michael_map::details::init_hash_bitmask( nMaxItemCount, nLoadFactor ))
+ , m_Buckets( bucket_table_allocator().allocate( bucket_count()))
{
- // GC and OrderedList::gc must be the same
- static_assert(( std::is_same<gc, typename bucket_type::gc>::value ), "GC and OrderedList::gc must be the same");
-
- // atomicity::empty_item_counter is not allowed as a item counter
- static_assert(( !std::is_same<item_counter, atomicity::empty_item_counter>::value ), "atomicity::empty_item_counter is not allowed as a item counter");
-
- m_Buckets = bucket_table_allocator().NewArray( bucket_count() );
+ for ( auto it = m_Buckets, itEnd = m_Buckets + bucket_count(); it != itEnd; ++it )
+ construct_bucket<bucket_stat>( it );
}
/// Clears hash map and destroys it
~MichaelHashMap()
{
clear();
- bucket_table_allocator().Delete( m_Buckets, bucket_count() );
+ for ( auto it = m_Buckets, itEnd = m_Buckets + bucket_count(); it != itEnd; ++it )
+ it->~internal_bucket_type();
+ bucket_table_allocator().deallocate( m_Buckets, bucket_count() );
}
/// Inserts new node with key and default value
The function creates a node with \p key and default value, and then inserts the node created into the map.
Preconditions:
- - The \ref key_type should be constructible from value of type \p K.
+ - The \p key_type should be constructible from value of type \p K.
In trivial case, \p K is equal to \ref key_type.
- - The \ref mapped_type should be default-constructible.
+ - The \p mapped_type should be default-constructible.
The function applies RCU lock internally.
and then inserts the node created into the map.
Preconditions:
- - The \ref key_type should be constructible from \p key of type \p K.
- - The \ref mapped_type should be constructible from \p val of type \p V.
+ - The \p key_type should be constructible from \p key of type \p K.
+ - The \p mapped_type should be constructible from \p val of type \p V.
The function applies RCU lock internally.
- <tt>item.first</tt> is a const reference to item's key that cannot be changed.
- <tt>item.second</tt> is a reference to item's value that may be changed.
- User-defined functor \p func should guarantee that during changing item's value no any other changes
- could be made on this map's item by concurrent threads.
- The user-defined functor can be passed by reference using <tt>boost::ref</tt>
- and it is called only if inserting is successful.
+ The user-defined functor is called only if inserting is successful.
The key_type should be constructible from value of type \p K.
it is preferable that the initialization should be completed only if inserting is successful.
The function applies RCU lock internally.
+
+ @warning For \ref cds_nonintrusive_MichaelKVList_rcu "MichaelKVList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_nonintrusive_LazyKVList_rcu "LazyKVList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
*/
template <typename K, typename Func>
- bool insert_key( const K& key, Func func )
+ bool insert_with( const K& key, Func func )
{
- const bool bRet = bucket( key ).insert_key( key, func );
+ const bool bRet = bucket( key ).insert_with( key, func );
if ( bRet )
++m_ItemCounter;
return bRet;
}
-
- /// Ensures that the \p key exists in the map
+ /// Updates data by \p key
/**
- The operation performs inserting or changing data with lock-free manner.
+ The operation performs inserting or replacing the element with lock-free manner.
If the \p key not found in the map, then the new item created from \p key
- is inserted into the map (note that in this case the \ref key_type should be
- constructible from type \p K).
- Otherwise, the functor \p func is called with item found.
- The functor \p Func may be a function with signature:
- \code
- void func( bool bNew, value_type& item );
- \endcode
- or a functor:
+ will be inserted into the map iff \p bAllowInsert is \p true.
+ (note that in this case the \ref key_type should be constructible from type \p K).
+ Otherwise, if \p key is found, the functor \p func is called with item found.
+
+ The functor \p Func signature is:
\code
struct my_functor {
void operator()( bool bNew, value_type& item );
};
\endcode
-
with arguments:
- \p bNew - \p true if the item has been inserted, \p false otherwise
- - \p item - item of the list
-
- The functor may change any fields of the \p item.second that is \ref mapped_type;
- however, \p func must guarantee that during changing no any other modifications
- could be made on this item by concurrent threads.
+ - \p item - the item found or inserted
- You may pass \p func argument by reference using <tt>boost::ref</tt>.
+ The functor may change any fields of the \p item.second that is \p mapped_type.
The function applies RCU lock internally.
- Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
+ Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successful,
\p second is true if new item has been added or \p false if the item with \p key
- already is in the list.
+ already exists.
+
+ @warning For \ref cds_nonintrusive_MichaelKVList_rcu "MichaelKVList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_nonintrusive_LazyKVList_rcu "LazyKVList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
*/
template <typename K, typename Func>
- std::pair<bool, bool> ensure( K const& key, Func func )
+ std::pair<bool, bool> update( K const& key, Func func, bool bAllowInsert = true )
{
- std::pair<bool, bool> bRet = bucket( key ).ensure( key, func );
- if ( bRet.first && bRet.second )
+ std::pair<bool, bool> bRet = bucket( key ).update( key, func, bAllowInsert );
+ if ( bRet.second )
++m_ItemCounter;
return bRet;
}
+ //@cond
+ template <typename K, typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
+ std::pair<bool, bool> ensure( K const& key, Func func )
+ {
+ return update( key, func, true );
+ }
+ //@endcond
-# ifdef CDS_EMPLACE_SUPPORT
- /// For key \p key inserts data of type \ref mapped_type constructed with <tt>std::forward<Args>(args)...</tt>
+ /// For key \p key inserts data of type \p mapped_type created from \p args
/**
\p key_type should be constructible from type \p K
Returns \p true if inserting successful, \p false otherwise.
-
- The function applies RCU lock internally.
-
- @note This function is available only for compiler that supports
- variadic template and move semantics
*/
template <typename K, typename... Args>
bool emplace( K&& key, Args&&... args )
++m_ItemCounter;
return bRet;
}
-# endif
/// Deletes \p key from the map
/** \anchor cds_nonintrusive_MichaelMap_rcu_erase_val
void operator()(value_type& item) { ... }
};
\endcode
- The functor may be passed by reference using <tt>boost:ref</tt>
RCU \p synchronize method can be called. RCU should not be locked.
/// Extracts an item from the map
/** \anchor cds_nonintrusive_MichaelHashMap_rcu_extract
The function searches an item with key equal to \p key,
- unlinks it from the map, places item pointer into \p dest argument, and returns \p true.
- If the item is not found the function return \p false.
+ unlinks it from the map, and returns \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the item found.
+ If the item is not found the function return an empty \p exempt_ptr.
- @note The function does NOT call RCU read-side lock or synchronization,
- and does NOT dispose the item found. It just excludes the item from the map
- and returns a pointer to item found.
- You should lock RCU before calling of the function, and you should synchronize RCU
- outside the RCU lock to free extracted item
+ The function just excludes the key from the map and returns a pointer to item found.
+ Depends on \p ordered_list you should or should not lock RCU before calling of this function:
+ - for the set based on \ref cds_nonintrusive_MichaelList_rcu "MichaelList" RCU should not be locked
+ - for the set based on \ref cds_nonintrusive_LazyList_rcu "LazyList" RCU should be locked
+ See ordered list implementation for details.
\code
#include <cds/urcu/general_buffered.h>
// ...
rcu_michael_map::exempt_ptr p;
- {
- // first, we should lock RCU
- rcu_michael_map::rcu_lock lock;
-
- // Now, you can apply extract function
- // Note that you must not delete the item found inside the RCU lock
- if ( theMap.extract( p, 10 )) {
- // do something with p
- ...
- }
+
+ // For MichaelList we should not lock RCU
+
+ // Note that you must not delete the item found inside the RCU lock
+ p = theMap.extract( 10 );
+ if ( p ) {
+ // do something with p
+ ...
}
// We may safely release p here
\endcode
*/
template <typename K>
- bool extract( exempt_ptr& dest, K const& key )
+ exempt_ptr extract( K const& key )
{
- if ( bucket( key ).extract( dest, key )) {
+ exempt_ptr p = bucket( key ).extract( key );
+ if ( p )
--m_ItemCounter;
- return true;
- }
- return false;
+ return p;
}
/// Extracts an item from the map using \p pred predicate for searching
/**
- The function is an analog of \ref cds_nonintrusive_MichaelHashMap_rcu_extract "extract(exempt_ptr&, K const&)"
- but \p pred is used for key comparing.
+ The function is an analog of \p extract(K const&) but \p pred is used for key comparing.
\p Less functor has the interface like \p std::less.
\p pred must imply the same element order as the comparator used for building the map.
*/
template <typename K, typename Less>
- bool extract_with( exempt_ptr& dest, K const& key, Less pred )
+ exempt_ptr extract_with( K const& key, Less pred )
{
- if ( bucket( key ).extract_with( dest, key, pred )) {
+ exempt_ptr p = bucket( key ).extract_with( key, pred );
+ if ( p )
--m_ItemCounter;
- return true;
- }
- return false;
+ return p;
}
/// Finds the key \p key
\endcode
where \p item is the item found.
- You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
-
The functor may change \p item.second. Note that the functor is only guarantee
that \p item cannot be disposed during functor is executing.
The functor does not serialize simultaneous access to the map's \p item. If such access is
The function returns \p true if \p key is found, \p false otherwise.
*/
template <typename K, typename Func>
- bool find( K const& key, Func f ) const
+ bool find( K const& key, Func f )
{
return bucket( key ).find( key, f );
}
\p Less must imply the same element order as the comparator used for building the map.
*/
template <typename K, typename Less, typename Func>
- bool find_with( K const& key, Less pred, Func f ) const
+ bool find_with( K const& key, Less pred, Func f )
{
return bucket( key ).find_with( key, pred, f );
}
- /// Finds the key \p key
- /** \anchor cds_nonintrusive_MichaelMap_rcu_find_val
-
+ /// Checks whether the map contains \p key
+ /**
The function searches the item with key equal to \p key
and returns \p true if it is found, and \p false otherwise.
The function applies RCU lock internally.
*/
template <typename K>
- bool find( K const& key ) const
+ bool contains( K const& key )
{
- return bucket( key ).find( key );
+ return bucket( key ).contains( key );
}
+ //@cond
+ template <typename K>
+ CDS_DEPRECATED("deprecated, use contains()")
+ bool find( K const& key )
+ {
+ return bucket( key ).contains( key );
+ }
+ //@endcond
- /// Finds the key \p val using \p pred predicate for searching
+ /// Checks whether the map contains \p key using \p pred predicate for searching
/**
- The function is an analog of \ref cds_nonintrusive_MichaelMap_rcu_find_val "find(K const&)"
- but \p pred is used for key comparing.
+ The function is an analog of <tt>contains( key )</tt> but \p pred is used for key comparing.
\p Less functor has the interface like \p std::less.
\p Less must imply the same element order as the comparator used for building the map.
*/
template <typename K, typename Less>
- bool find_with( K const& key, Less pred ) const
+ bool contains( K const& key, Less pred )
+ {
+ return bucket( key ).contains( key, pred );
+ }
+ //@cond
+ template <typename K, typename Less>
+ CDS_DEPRECATED("deprecated, use contains()")
+ bool find_with( K const& key, Less pred )
{
- return bucket( key ).find_with( key, pred );
+ return bucket( key ).contains( key, pred );
}
+ //@endcond
/// Finds \p key and return the item found
/** \anchor cds_nonintrusive_MichaelHashMap_rcu_get
The function searches the item with key equal to \p key and returns the pointer to item found.
- If \p key is not found it returns \p NULL.
+ If \p key is not found it returns \p nullptr.
+ Note the type of returned value depends on underlying \p ordered_list.
+ For details, see documentation of ordered list you use.
Note the compare functor should accept a parameter of type \p K that can be not the same as \p key_type.
typedef cds::container::MichaelHashMap< your_template_parameters > hash_map;
hash_map theMap;
// ...
+ typename hash_map::raw_ptr gp;
{
// Lock RCU
hash_map::rcu_lock lock;
- hash_map::value_type * = theMap.get( 5 );
- if ( pVal ) {
- // Deal with pVal
+ gp = theMap.get( 5 );
+ if ( gp ) {
+ // Deal with gp
//...
}
// Unlock RCU by rcu_lock destructor
- // pVal can be freed at any time after RCU has been unlocked
+ // gp can be reclaimed at any time after RCU has been unlocked
}
\endcode
*/
template <typename K>
- value_type * get( K const& key ) const
+ raw_ptr get( K const& key )
{
return bucket( key ).get( key );
}
\p pred must imply the same element order as the comparator used for building the map.
*/
template <typename K, typename Less>
- value_type * get_with( K const& key, Less pred ) const
+ raw_ptr get_with( K const& key, Less pred )
{
return bucket( key ).get_with( key, pred );
}
- /// Clears the map (non-atomic)
+ /// Clears the map (not atomic)
/**
The function erases all items from the map.
return m_ItemCounter;
}
+ /// Returns const reference to internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
/// Returns the size of hash table
/**
- Since MichaelHashMap cannot dynamically extend the hash table size,
+ Since \p %MichaelHashMap cannot dynamically extend the hash table size,
the value returned is an constant depending on object initialization parameters;
- see MichaelHashMap::MichaelHashMap for explanation.
+ see \p MichaelHashMap::MichaelHashMap for explanation.
*/
size_t bucket_count() const
{
return m_nHashBitmask + 1;
}
+
+ protected:
+ //@cond
+ /// Calculates hash value of \p key
+ template <typename Q>
+ size_t hash_value( Q const& key ) const
+ {
+ return m_HashFunctor( key ) & m_nHashBitmask;
+ }
+
+ /// Returns the bucket (ordered list) for \p key
+ template <typename Q>
+ internal_bucket_type& bucket( Q const& key )
+ {
+ return m_Buckets[hash_value( key )];
+ }
+ template <typename Q>
+ internal_bucket_type const& bucket( Q const& key ) const
+ {
+ return m_Buckets[hash_value( key )];
+ }
+ //@endcond
+ private:
+ //@cond
+ const_iterator get_const_begin() const
+ {
+ return const_iterator( const_cast<internal_bucket_type const&>(m_Buckets[0]).begin(), m_Buckets, m_Buckets + bucket_count() );
+ }
+ const_iterator get_const_end() const
+ {
+ return const_iterator( const_cast<internal_bucket_type const&>(m_Buckets[bucket_count() - 1]).end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count() );
+ }
+
+ template <typename Stat>
+ typename std::enable_if< Stat::empty >::type construct_bucket( internal_bucket_type* bucket )
+ {
+ new (bucket) internal_bucket_type;
+ }
+
+ template <typename Stat>
+ typename std::enable_if< !Stat::empty >::type construct_bucket( internal_bucket_type* bucket )
+ {
+ new (bucket) internal_bucket_type( m_Stat );
+ }
+ //@endcond
};
}} // namespace cds::container
-#endif // ifndef __CDS_CONTAINER_MICHAEL_MAP_RCU_H
+#endif // ifndef CDSLIB_CONTAINER_MICHAEL_MAP_RCU_H
projects / libcds.git / blobdiff