//$$CDS-header$$
-#ifndef __CDS_CONTAINER_MICHAEL_MAP_RCU_H
-#define __CDS_CONTAINER_MICHAEL_MAP_RCU_H
+#ifndef CDSLIB_CONTAINER_MICHAEL_MAP_RCU_H
+#define CDSLIB_CONTAINER_MICHAEL_MAP_RCU_H
-#include <cds/container/michael_map_base.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.
+ - \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
- 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.
-
- 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 cds::urcu::gc< RCU > gc; ///< RCU used as garbage collector
+ typedef OrderedList bucket_type; ///< type of ordered list used as a bucket implementation
+ typedef Traits traits; ///< Map traits
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
/// 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
/// Bucket table allocator
- typedef cds::details::Allocator< bucket_type, typename options::allocator > bucket_table_allocator;
+ typedef cds::details::Allocator< bucket_type, typename traits::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
+ 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 = bucket_type::c_bExtractLockExternal;
protected:
- item_counter m_ItemCounter ; ///< Item counter
- hash m_HashFunctor ; ///< Hash functor
-
- bucket_type * m_Buckets ; ///< bucket table
+ item_counter m_ItemCounter; ///< Item counter
+ hash m_HashFunctor; ///< Hash functor
+ bucket_type * m_Buckets; ///< bucket table
private:
//@cond
//@endcond
protected:
+ //@cond
/// Calculates hash value of \p key
template <typename Q>
size_t hash_value( Q const& key ) const
}
/// Returns the bucket (ordered list) for \p key
- //@{
template <typename Q>
bucket_type& bucket( Q const& key )
{
{
return m_Buckets[ hash_value( key ) ];
}
- //@}
+ //@endcond
protected:
/// Forward iterator
/**
{
return get_const_begin();
}
- const_iterator cbegin()
+ const_iterator cbegin() const
{
return get_const_begin();
}
{
return get_const_end();
}
- const_iterator cend()
+ const_iterator cend() const
{
return get_const_end();
}
public:
/// Initializes the map
- /**
- The Michael's hash map is non-expandable container. You should point the average count of items \p nMaxItemCount
- when you create an object.
- \p nLoadFactor parameter defines average count of items per bucket and it should be small number between 1 and 10.
- Remember, since the bucket implementation is an ordered list, searching in the bucket is linear [<tt>O(nLoadFactor)</tt>].
- Note, that many popular STL hash map implementation uses load factor 1.
-
- The ctor defines hash table size as rounding <tt>nMacItemCount / nLoadFactor</tt> up to nearest power of two.
+ /** @copydetails cds_nonintrusive_MichaelHashMap_hp_ctor
*/
MichaelHashMap(
size_t nMaxItemCount, ///< estimation of max item count in the hash map
) : m_nHashBitmask( michael_map::details::init_hash_bitmask( nMaxItemCount, nLoadFactor ))
{
// 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");
+ 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");
+ 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");
m_Buckets = bucket_table_allocator().NewArray( bucket_count() );
}
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;
- \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.
-
- 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 \ref mapped_type.
The function applies RCU lock internally.
Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
\p second is true if new item has been added or \p false if the item with \p key
already is in the list.
+
+ @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 )
return bRet;
}
-# 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
// Now, you can apply extract function
// Note that you must not delete the item found inside the RCU lock
- if ( theMap.extract( p, 10 )) {
+ p = theMap.extract( 10 );
+ if ( p ) {
// do something with p
...
}
\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
\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
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.
/// 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
{
};
}} // namespace cds::container
-#endif // ifndef __CDS_CONTAINER_MICHAEL_MAP_RCU_H
+#endif // ifndef CDSLIB_CONTAINER_MICHAEL_MAP_RCU_H
projects / libcds.git / blobdiff