//$$CDS-header$$
-#ifndef __CDS_CONTAINER_MICHAEL_SET_RCU_H
-#define __CDS_CONTAINER_MICHAEL_SET_RCU_H
+#ifndef CDSLIB_CONTAINER_MICHAEL_SET_RCU_H
+#define CDSLIB_CONTAINER_MICHAEL_SET_RCU_H
#include <cds/container/details/michael_set_base.h>
#include <cds/details/allocator.h>
Template parameters are:
- \p RCU - one of \ref cds_urcu_gc "RCU type"
- - \p OrderedList - ordered list implementation used as bucket for hash set, for example, MichaelList.
+ - \p OrderedList - ordered list implementation used as the bucket for hash set, for example,
+ \ref cds_nonintrusive_MichaelList_rcu "MichaelList".
The ordered list implementation specifies the type \p T stored in the hash-set,
the comparison functor for the type \p T and other features specific for
the ordered list.
- - \p Traits - type traits. See michael_set::type_traits for explanation.
+ - \p Traits - set traits, default is michael_set::traits.
+ Instead of defining \p Traits struct you may use option-based syntax with michael_set::make_traits metafunction.
- Instead of defining \p Traits struct you may use option-based syntax with michael_set::make_traits metafunction.
- For michael_set::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_set::type_traits for explanation.
- - opt::allocator - optional, bucket table allocator. Default is \ref CDS_DEFAULT_ALLOCATOR.
-
- \note About hash functor see \ref cds_nonintrusive_MichaelHashSet_hash_functor "MichaelSet".
+ About hash functor see \ref cds_nonintrusive_MichaelHashSet_hash_functor "MichaelSet hash functor".
<b>How to use</b>
- Suppose, we have the following type \p Foo that we want to store in our MichaelHashSet:
+ Suppose, we have the following type \p Foo that we want to store in your \p %MichaelHashSet:
\code
struct Foo {
int nKey ; // key field
}
};
- // Our ordered list
+ // Ordered list
typedef cc::MichaelList< cds::urcu::gc< cds::urcu::general_buffered<> >, Foo,
typename cc::michael_list::make_traits<
cc::opt::compare< Foo_cmp > // item comparator option
}
};
- // Declare set type.
+ // Declare the set
// Note that \p RCU template parameter of ordered list must be equal \p RCU for the set.
typedef cc::MichaelHashSet< cds::urcu::gc< cds::urcu::general_buffered<> >, bucket_list,
cc::michael_set::make_traits<
>::type
> foo_set;
- // Set variable
foo_set fooSet;
\endcode
*/
class RCU,
class OrderedList,
#ifdef CDS_DOXYGEN_INVOKED
- class Traits = michael_set::type_traits
+ class Traits = michael_set::traits
#else
class Traits
#endif
class MichaelHashSet< 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 to be used as a bucket implementation
+ typedef Traits traits; ///< Set traits
- typedef typename bucket_type::value_type value_type ; ///< type of value stored in the list
- typedef cds::urcu::gc< RCU > gc ; ///< RCU used as garbage collector
- typedef typename bucket_type::key_comparator key_comparator ; ///< key comparing functor
+ typedef typename bucket_type::value_type value_type; ///< type of value to be stored in the list
+ typedef typename bucket_type::key_comparator key_comparator; ///< key comparing functor
/// Hash functor for \ref value_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
+ typedef typename bucket_type::raw_ptr raw_ptr; ///< Return type of \p get() member function and its derivatives
/// 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;
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
public:
/// 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();
}
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.
+ The ctor defines hash table size as rounding <tt>nMaxItemCount / nLoadFactor</tt> up to nearest power of two.
*/
MichaelHashSet(
size_t nMaxItemCount, ///< estimation of max item count in the hash set
) : m_nHashBitmask( michael_set::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, atomicity::empty_item_counter>::value,
+ "atomicity::empty_item_counter is not allowed as a item counter");
m_Buckets = bucket_table_allocator().NewArray( bucket_count() );
}
- /// Clear hash set and destroy it
+ /// Clears hash set and destroys it
~MichaelHashSet()
{
clear();
\code
void func( value_type& val );
\endcode
- where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
- \p val no any other changes could be made on this set's item by concurrent threads.
- The user-defined functor is called only if the inserting is success. It may be passed by reference
- using \p std::ref
+ where \p val is the item inserted.
+ The user-defined functor is called only if the inserting is success.
The function applies RCU lock internally.
- */
+
+ @warning For \ref cds_nonintrusive_MichaelList_rcu "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_nonintrusive_LazyList_rcu "LazyList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
+ */
template <typename Q, typename Func>
bool insert( Q const& val, Func f )
{
If the \p val key not found in the set, then the new item created from \p val
is inserted into the set. Otherwise, the functor \p func is called with the item found.
- The functor \p Func should be a function with signature:
- \code
- void func( bool bNew, value_type& item, const Q& val );
- \endcode
- or a functor:
+ The functor \p Func signature is:
\code
struct my_functor {
void operator()( bool bNew, value_type& item, const Q& val );
- \p item - item of the set
- \p val - argument \p key passed into the \p ensure function
- The functor may change non-key fields of the \p item; 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 \p std::ref
+ The functor may change non-key fields of the \p item.
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 set.
+
+ @warning For \ref cds_nonintrusive_MichaelList_rcu "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_nonintrusive_LazyList_rcu "LazyList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
+ */
+ /// Updates the element
+ /**
+ The operation performs inserting or changing data with lock-free manner.
+
+ If the item \p val not found in the set, then \p val is inserted iff \p bAllowInsert is \p true.
+ Otherwise, the functor \p func is called with item found.
+ The functor signature is:
+ \code
+ struct functor {
+ void operator()( bool bNew, value_type& item, Q const& val );
+ };
+ \endcode
+ with arguments:
+ - \p bNew - \p true if the item has been inserted, \p false otherwise
+ - \p item - item of the set
+ - \p val - argument \p val passed into the \p %update() function
+
+ The functor may change non-key fields of the \p item.
+
+ The function applies RCU lock internally.
+
+ Returns <tt> std::pair<bool, bool> </tt> where \p first is \p true if operation is successfull,
+ \p second is \p true if new item has been added or \p false if the item with \p key
+ already is in the set.
+
+ @warning For \ref cds_intrusive_MichaelList_hp "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_intrusive_LazyList_hp "LazyList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
*/
template <typename Q, typename Func>
- std::pair<bool, bool> ensure( const Q& val, Func func )
+ std::pair<bool, bool> update( const Q& val, Func func, bool bAllowInsert = true )
{
- std::pair<bool, bool> bRet = bucket( val ).ensure( val, func );
- if ( bRet.first && bRet.second )
+ std::pair<bool, bool> bRet = bucket( val ).update( val, func, bAllowInsert );
+ if ( bRet.second )
++m_ItemCounter;
return bRet;
+ }//@cond
+ template <typename Q, typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
+ std::pair<bool, bool> ensure( const Q& val, Func func )
+ {
+ return update( val, func, true );
}
+ //@endcond
- /// Inserts data of type \ref value_type constructed with <tt>std::forward<Args>(args)...</tt>
+ /// Inserts data of type \p value_type created from \p args
/**
Returns \p true if inserting successful, \p false otherwise.
/// Deletes \p key from the set
/** \anchor cds_nonintrusive_MichealSet_rcu_erase_val
- Since the key of MichaelHashSet's item type \ref value_type is not explicitly specified,
+ Since the key of MichaelHashSet's item type \p value_type is not explicitly specified,
template parameter \p Q defines the key type searching in the list.
The set item comparator should be able to compare the type \p value_type
and the type \p Q.
void operator()(value_type const& val);
};
\endcode
- The functor may be passed by reference using <tt>boost:ref</tt>
Since the key of %MichaelHashSet's \p value_type is not explicitly specified,
template parameter \p Q defines the key type searching in the list.
/// Extracts an item from the set
/** \anchor cds_nonintrusive_MichaelHashSet_rcu_extract
- The function searches an item with key equal to \p val in the set,
- unlinks it from the set, places item pointer into \p dest argument, and returns \p true.
- If the item with the key equal to \p val is not found the function return \p false.
+ The function searches an item with key equal to \p key in the set,
+ unlinks it from the set, and returns \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the item found.
+ If the item with the key equal to \p key 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 set
- 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 item from the set and returns a pointer to item found.
+ Depends on \p bucket_type 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_set theSet;
// ...
- rcu_michael_set::exempt_ptr p;
- {
- // first, we should lock RCU
- rcu_michael_set::rcu_lock lock;
-
- // Now, you can apply extract function
- // Note that you must not delete the item found inside the RCU lock
- if ( theSet.extract( p, 10 )) {
- // do something with p
- ...
- }
+ typename rcu_michael_set::exempt_ptr p;
+
+ // For MichaelList we should not lock RCU
+
+ // Note that you must not delete the item found inside the RCU lock
+ p = theSet.extract( 10 );
+ if ( p ) {
+ // do something with p
+ ...
}
// We may safely release p here
\endcode
*/
template <typename Q>
- bool extract( exempt_ptr& dest, Q const& val )
+ exempt_ptr extract( Q const& key )
{
- if ( bucket( val ).extract( dest, val )) {
+ exempt_ptr p = bucket( key ).extract( key );
+ if ( p )
--m_ItemCounter;
- return true;
- }
- return false;
+ return p;
}
/// Extracts an item from the set using \p pred predicate for searching
/**
- The function is an analog of \ref cds_nonintrusive_MichaelHashSet_rcu_extract "extract(exempt_ptr&, Q const&)"
- but \p pred is used for key comparing.
+ The function is an analog of \p extract(Q 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 set.
*/
template <typename Q, typename Less>
- bool extract_with( exempt_ptr& dest, Q const& val, Less pred )
+ exempt_ptr extract_with( Q const& key, Less pred )
{
- if ( bucket( val ).extract_with( dest, val, pred )) {
+ exempt_ptr p = bucket( key ).extract_with( key, pred );
+ if ( p )
--m_ItemCounter;
- return true;
- }
- return false;
+ return p;
}
- /// Finds the key \p val
+ /// Finds the key \p key
/** \anchor cds_nonintrusive_MichealSet_rcu_find_func
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
+ The function searches the item with key equal to \p key and calls the functor \p f for item found.
The interface of \p Func functor is:
\code
struct functor {
- void operator()( value_type& item, Q& val );
+ void operator()( value_type& item, Q& key );
};
\endcode
- where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
- You may pass \p f argument by reference using \p std::ref.
+ where \p item is the item found, \p key is the <tt>find</tt> function argument.
The functor may change non-key fields of \p item. 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 set's \p item. If such access is
possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
- The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
+ The \p key argument is non-const since it can be used as \p f functor destination i.e., the functor
can modify both arguments.
Note the hash functor specified for class \p Traits template parameter
The function applies RCU lock internally.
- The function returns \p true if \p val is found, \p false otherwise.
+ The function returns \p true if \p key is found, \p false otherwise.
*/
template <typename Q, typename Func>
- bool find( Q& val, Func f ) const
+ bool find( Q& key, Func f )
{
- return bucket( val ).find( val, f );
+ return bucket( key ).find( key, f );
}
+ //@cond
+ template <typename Q, typename Func>
+ bool find( Q const& key, Func f )
+ {
+ return bucket( key ).find( key, f );
+ }
+ //@endcond
- /// Finds the key \p val using \p pred predicate for searching
+ /// Finds the key \p key using \p pred predicate for searching
/**
The function is an analog of \ref cds_nonintrusive_MichealSet_rcu_find_func "find(Q&, Func)"
but \p pred is used for key comparing.
\p Less must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less, typename Func>
- bool find_with( Q& val, Less pred, Func f ) const
+ bool find_with( Q& key, Less pred, Func f )
{
- return bucket( val ).find_with( val, pred, f );
+ return bucket( key ).find_with( key, pred, f );
}
-
- /// Finds the key \p val
- /** \anchor cds_nonintrusive_MichealSet_rcu_find_cfunc
-
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
- The interface of \p Func functor is:
- \code
- struct functor {
- void operator()( value_type& item, Q const& val );
- };
- \endcode
- where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
- You may pass \p f argument by reference using \p std::ref.
-
- The functor may change non-key fields of \p item. 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 set's \p item. If such access is
- possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
-
- Note the hash functor specified for class \p Traits template parameter
- should accept a parameter of type \p Q that may be not the same as \p value_type.
-
- The function applies RCU lock internally.
-
- The function returns \p true if \p val is found, \p false otherwise.
- */
- template <typename Q, typename Func>
- bool find( Q const& val, Func f ) const
- {
- return bucket( val ).find( val, f );
- }
-
- /// Finds the key \p val using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_nonintrusive_MichealSet_rcu_find_cfunc "find(Q const&, Func)"
- 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 set.
- */
+ //@cond
template <typename Q, typename Less, typename Func>
- bool find_with( Q const& val, Less pred, Func f ) const
+ bool find_with( Q const& key, Less pred, Func f )
{
- return bucket( val ).find_with( val, pred, f );
+ return bucket( key ).find_with( key, pred, f );
}
+ //@endcond
- /// Finds the key \p val
- /** \anchor cds_nonintrusive_MichealSet_rcu_find_val
-
- The function searches the item with key equal to \p val
- and returns \p true if it is found, and \p false otherwise.
+ /// Checks whether the set contains \p key
+ /**
+ The function searches the item with key equal to \p key
+ and returns \p true if the key is found, and \p false otherwise.
Note the hash functor specified for class \p Traits template parameter
- should accept a parameter of type \p Q that may be not the same as \ref value_type.
+ should accept a parameter of type \p Q that can be not the same as \p value_type.
*/
template <typename Q>
- bool find( Q const & val ) const
+ bool contains( Q const& key )
+ {
+ return bucket( key ).contains( key );
+ }
+ //@cond
+ template <typename Q>
+ CDS_DEPRECATED("use contains()")
+ bool find( Q const& key )
{
- return bucket( val ).find( val );
+ return contains( key );
}
+ //@endcond
- /// Finds the key \p val using \p pred predicate for searching
+ /// Checks whether the set contains \p key using \p pred predicate for searching
/**
- The function is an analog of \ref cds_nonintrusive_MichealSet_rcu_find_val "find(Q 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 set.
*/
template <typename Q, typename Less>
- bool find_with( Q const & val, Less pred ) const
+ bool contains( Q const& key, Less pred )
+ {
+ return bucket( key ).contains( key, pred );
+ }
+ //@cond
+ template <typename Q, typename Less>
+ CDS_DEPRECATED("use contains()")
+ bool find_with( Q const& key, Less pred )
{
- return bucket( val ).find_with( val, pred );
+ return contains( key, pred );
}
+ //@endcond
- /// Finds the key \p val and return the item found
+ /// Finds the key \p key and return the item found
/** \anchor cds_nonintrusive_MichaelHashSet_rcu_get
- The function searches the item with key equal to \p val and returns the pointer to item found.
- If \p val is not found it returns \p nullptr.
+ 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 nullptr.
+ Note the type of returned value depends on underlying \p bucket_type.
+ For details, see documentation of ordered list you use.
Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
\code
typedef cds::container::MichaelHashSet< your_template_parameters > hash_set;
hash_set theSet;
+ typename hash_set::raw_ptr gp;
// ...
{
// Lock RCU
hash_set::rcu_lock lock;
- foo * pVal = theSet.get( 5 );
- if ( pVal ) {
+ gp = theSet.get( 5 );
+ if ( gp ) {
// Deal with pVal
//...
}
// 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 Q>
- value_type * get( Q const& val ) const
+ raw_ptr get( Q const& key )
{
- return bucket( val ).get( val );
+ return bucket( key ).get( key );
}
- /// Finds the key \p val and return the item found
+ /// Finds the key \p key and return the item found
/**
The function is an analog of \ref cds_nonintrusive_MichaelHashSet_rcu_get "get(Q const&)"
but \p pred is used for comparing the keys.
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- value_type * get_with( Q const& val, Less pred ) const
+ raw_ptr get_with( Q const& key, Less pred )
{
- return bucket( val ).get_with( val, pred );
+ return bucket( key ).get_with( key, pred );
}
- /// Clears the set (non-atomic)
- /**
- The function erases all items from the set.
-
- The function is not atomic. It cleans up each bucket and then resets the item counter to zero.
- If there are a thread that performs insertion while \p clear is working the result is undefined in general case:
- <tt> empty() </tt> may return \p true but the set may contain item(s).
- Therefore, \p clear may be used only for debugging purposes.
-
- RCU \p synchronize method can be called. RCU should not be locked.
- */
+ /// Clears the set (not atomic)
void clear()
{
for ( size_t i = 0; i < bucket_count(); ++i )
/// Returns the size of hash table
/**
- Since MichaelHashSet cannot dynamically extend the hash table size,
+ Since \p %MichaelHashSet cannot dynamically extend the hash table size,
the value returned is an constant depending on object initialization parameters;
see MichaelHashSet::MichaelHashSet for explanation.
*/
}} // namespace cds::container
-#endif // ifndef __CDS_CONTAINER_MICHAEL_SET_H
+#endif // ifndef CDSLIB_CONTAINER_MICHAEL_SET_RCU_H
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