-//$$CDS-header$$
+/*
+ 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_INTRUSIVE_IMPL_LAZY_LIST_H
#define CDSLIB_INTRUSIVE_IMPL_LAZY_LIST_H
- \p T - type to be stored in the list. The type must be based on lazy_list::node (for lazy_list::base_hook)
or it must have a member of type lazy_list::node (for lazy_list::member_hook).
- \p Traits - type traits. See lazy_list::traits for explanation.
- It is possible to declare option-based list with cds::intrusive::lazy_list::make_traits metafunction istead of \p Traits template
+ It is possible to declare option-based list with cds::intrusive::lazy_list::make_traits metafunction instead of \p Traits template
argument. For example, the following traits-based declaration of \p gc::HP lazy list
\code
#include <cds/intrusive/lazy_list_hp.h>
typedef typename hook::node_type node_type; ///< node type
# ifdef CDS_DOXYGEN_INVOKED
- typedef implementation_defined key_comparator ; ///< key comparison functor based on opt::compare and opt::less option setter.
+ typedef implementation_defined key_comparator; ///< key comparison functor based on opt::compare and opt::less option setter.
# else
typedef typename opt::details::make_comparator< value_type, traits >::type key_comparator;
# endif
typedef typename get_node_traits< value_type, node_type, hook>::type node_traits; ///< node traits
typedef typename lazy_list::get_link_checker< node_type, traits::link_checker >::type link_checker; ///< link checker
- typedef typename traits::back_off back_off ; ///< back-off strategy
- typedef typename traits::item_counter item_counter ; ///< Item counting policy used
- typedef typename traits::memory_model memory_model; ///< C++ memory ordering (see \p lazy_list::traits::memory_model)
+ typedef typename traits::back_off back_off; ///< back-off strategy
+ typedef typename traits::item_counter item_counter; ///< Item counting policy used
+ typedef typename traits::memory_model memory_model; ///< C++ memory ordering (see \p lazy_list::traits::memory_model)
+ typedef typename traits::stat stat; ///< Internal statistics
+
+ static_assert((std::is_same< gc, typename node_type::gc >::value), "GC and node_type::gc must be the same type");
typedef typename gc::template guarded_ptr< value_type > guarded_ptr; ///< Guarded pointer
+ static CDS_CONSTEXPR const size_t c_nHazardPtrCount = 4; ///< Count of hazard pointer required for the algorithm
+
//@cond
// Rebind traits (split-list support)
template <typename... Options>
gc
, value_type
, typename cds::opt::make_options< traits, Options...>::type
- > type;
+ > type;
};
+
+ // Stat selector
+ template <typename Stat>
+ using select_stat_wrapper = lazy_list::select_stat_wrapper< Stat >;
//@endcond
protected:
node_type m_Head;
node_type m_Tail;
- item_counter m_ItemCounter ; ///< Item counter
+ item_counter m_ItemCounter;
+ stat m_Stat; ///< Internal statistics
- //@cond
struct clean_disposer {
void operator()( value_type * p )
{
- lazy_list::node_cleaner<gc, node_type, memory_model>()( node_traits::to_node_ptr( p ) );
+ lazy_list::node_cleaner<gc, node_type, memory_model>()( node_traits::to_node_ptr( p ));
disposer()( p );
}
};
/// Position pointer for item search
struct position {
- node_type * pPred ; ///< Previous node
- node_type * pCur ; ///< Current node
+ node_type * pPred; ///< Previous node
+ node_type * pCur; ///< Current node
- typename gc::template GuardArray<2> guards ; ///< Guards array
+ typename gc::template GuardArray<2> guards; ///< Guards array
enum {
guard_prev_item,
}
};
- class auto_lock_position {
- position& m_pos;
- public:
- auto_lock_position( position& pos )
- : m_pos(pos)
- {
- pos.lock();
- }
- ~auto_lock_position()
- {
- m_pos.unlock();
- }
- };
+ typedef std::unique_lock< position > scoped_position_lock;
//@endcond
protected:
void link_node( node_type * pNode, node_type * pPred, node_type * pCur )
{
assert( pPred->m_pNext.load(memory_model::memory_order_relaxed).ptr() == pCur );
+ link_checker::is_empty( pNode );
pNode->m_pNext.store( marked_node_ptr(pCur), memory_model::memory_order_release );
pPred->m_pNext.store( marked_node_ptr(pNode), memory_model::memory_order_release );
assert( pPred->m_pNext.load(memory_model::memory_order_relaxed).ptr() == pCur );
node_type * pNext = pCur->m_pNext.load(memory_model::memory_order_relaxed).ptr();
- //pCur->m_pNext.store( marked_node_ptr( pNext, 1), memory_model::memory_order_release) ; // logically deleting
- pCur->m_pNext.store( marked_node_ptr( pHead, 1 ), memory_model::memory_order_release ) ; // logical removal + back-link for search
+ pCur->m_pNext.store( marked_node_ptr( pHead, 1 ), memory_model::memory_order_release ); // logical removal + back-link for search
pPred->m_pNext.store( marked_node_ptr( pNext ), memory_model::memory_order_release); // physically deleting
- //pCur->m_pNext.store( marked_node_ptr( pHead, 1 ), memory_model::memory_order_release ) ; // back-link for search
}
void retire_node( node_type * pNode )
{
assert( pNode != nullptr );
- gc::template retire<clean_disposer>( node_traits::to_value_ptr( *pNode ) );
+ gc::template retire<clean_disposer>( node_traits::to_value_ptr( *pNode ));
}
//@endcond
do {
pNext = pCur->m_pNext.load(memory_model::memory_order_relaxed).ptr();
g.assign( node_traits::to_value_ptr( pNext ));
- } while ( pNext != pCur->m_pNext.load(memory_model::memory_order_relaxed).ptr() );
+ } while ( pNext != pCur->m_pNext.load(memory_model::memory_order_relaxed).ptr());
- m_pNode = m_Guard.assign( g.template get<value_type>() );
+ m_pNode = m_Guard.assign( g.template get<value_type>());
}
}
}
node_type * pNode = node_traits::to_node_ptr( m_pNode );
// Dummy tail node could not be marked
- while ( pNode->is_marked() ) {
+ while ( pNode->is_marked()) {
node_type * p = pNode->m_pNext.load(memory_model::memory_order_relaxed).ptr();
g.assign( node_traits::to_value_ptr( p ));
- if ( p == pNode->m_pNext.load(memory_model::memory_order_relaxed).ptr() )
+ if ( p == pNode->m_pNext.load(memory_model::memory_order_relaxed).ptr())
pNode = p;
}
- if ( pNode != node_traits::to_node_ptr( m_pNode ) )
- m_pNode = m_Guard.assign( g.template get<value_type>() );
+ if ( pNode != node_traits::to_node_ptr( m_pNode ))
+ m_pNode = m_Guard.assign( g.template get<value_type>());
}
}
//@endcond
public:
+ ///@name Forward iterators (only for debugging purpose)
+ //@{
/// Forward iterator
/**
The forward iterator for lazy list has some features:
- The iterator cannot be moved across thread boundary since it contains 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 list.
+ Moreover, a crash is possible when you try to iterate the next element that has been deleted by concurrent thread.
- Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator on the concurrent container
- for debug purpose only.
+ @warning Use this iterator on the concurrent container for debugging purpose only.
*/
typedef iterator_type<false> iterator;
/// Const forward iterator
}
/// Returns a forward const iterator addressing the first element in a list
- //@{
const_iterator begin() const
{
return get_const_begin();
}
+
+ /// Returns a forward const iterator addressing the first element in a list
const_iterator cbegin() const
{
return get_const_begin();
}
- //@}
/// Returns an const iterator that addresses the location succeeding the last element in a list
- //@{
const_iterator end() const
{
return get_const_end();
}
+
+ /// Returns an const iterator that addresses the location succeeding the last element in a list
const_iterator cend() const
{
return get_const_end();
}
- //@}
+ //@}
private:
//@cond
}
const_iterator get_const_end() const
{
- return const_iterator( const_cast<node_type *>(&m_Tail) );
+ return const_iterator( const_cast<node_type *>(&m_Tail));
}
//@endcond
/// Default constructor initializes empty list
LazyList()
{
- static_assert( (std::is_same< gc, typename node_type::gc >::value), "GC and node_type::gc must be the same type" );
m_Head.m_pNext.store( marked_node_ptr( &m_Tail ), memory_model::memory_order_relaxed );
}
+ //@cond
+ template <typename Stat, typename = std::enable_if<std::is_same<stat, lazy_list::wrapped_stat<Stat>>::value >>
+ explicit LazyList( Stat& st )
+ : m_Stat( st )
+ {
+ m_Head.m_pNext.store( marked_node_ptr( &m_Tail ), memory_model::memory_order_relaxed );
+ }
+ //@endcond
+
/// Destroys the list object
~LazyList()
{
While the functor \p f is working the item \p item is locked,
so \p func has exclusive access to the item.
- Returns <tt> std::pair<bool, bool> </tt> where \p first is \p true if operation is successfull,
+ Returns <tt> std::pair<bool, bool> </tt> where \p first is \p true if operation is successful,
\p second is \p true if new item has been added or \p false if the item with \p key
already is in the list.
is equal to <tt> &val </tt>.
The function returns \p true if success and \p false otherwise.
+
+ \p disposer specified in \p Traits is called for unlinked item.
*/
bool unlink( value_type& val )
{
The function searches an item with key equal to \p key in the list,
unlinks it from the list, and returns \p true.
If the item with the key equal to \p key is not found the function return \p false.
+
+ \p disposer specified in \p Traits is called for deleted item.
*/
template <typename Q>
bool erase( Q const& key )
{
- return erase_at( &m_Head, key, key_comparator() );
+ return erase_at( &m_Head, key, key_comparator());
}
/// Deletes the item from the list using \p pred predicate for searching
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 list.
+
+ \p disposer specified in \p Traits is called for deleted item.
*/
template <typename Q, typename Less>
bool erase_with( Q const& key, Less pred )
{
CDS_UNUSED( pred );
- return erase_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>() );
+ return erase_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>());
}
/// Deletes the item from the list
\endcode
If \p key is not found the function return \p false.
+
+ \p disposer specified in \p Traits is called for deleted item.
*/
template <typename Q, typename Func>
bool erase( const Q& key, Func func )
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 list.
+
+ \p disposer specified in \p Traits is called for deleted item.
*/
template <typename Q, typename Less, typename Func>
bool erase_with( const Q& key, Less pred, Func func )
guarded_ptr extract( Q const& key )
{
guarded_ptr gp;
- extract_at( &m_Head, gp.guard(), key, key_comparator() );
+ extract_at( &m_Head, gp.guard(), key, key_comparator());
return gp;
}
{
CDS_UNUSED( pred );
guarded_ptr gp;
- extract_at( &m_Head, gp.guard(), key, cds::opt::details::make_comparator_from_less<Less>() );
+ extract_at( &m_Head, gp.guard(), key, cds::opt::details::make_comparator_from_less<Less>());
return gp;
}
template <typename Q>
bool contains( Q const& key )
{
- return find_at( &m_Head, key, key_comparator() );
+ return find_at( &m_Head, key, key_comparator());
}
//@cond
template <typename Q>
bool contains( Q const& key, Less pred )
{
CDS_UNUSED( pred );
- return find_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>() );
+ return find_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>());
}
//@cond
template <typename Q, typename Less>
guarded_ptr get( Q const& key )
{
guarded_ptr gp;
- get_at( &m_Head, gp.guard(), key, key_comparator() );
+ get_at( &m_Head, gp.guard(), key, key_comparator());
return gp;
}
{
CDS_UNUSED( pred );
guarded_ptr gp;
- get_at( &m_Head, gp.guard(), key, cds::opt::details::make_comparator_from_less<Less>() );
+ get_at( &m_Head, gp.guard(), key, cds::opt::details::make_comparator_from_less<Less>());
return gp;
}
{
typename gc::Guard guard;
marked_node_ptr h;
- while ( !empty() ) {
+ while ( !empty()) {
h = m_Head.m_pNext.load( memory_model::memory_order_relaxed );
- guard.assign( node_traits::to_value_ptr( h.ptr() ));
+ guard.assign( node_traits::to_value_ptr( h.ptr()));
if ( m_Head.m_pNext.load(memory_model::memory_order_acquire) == h ) {
m_Head.m_Lock.lock();
h->m_Lock.lock();
unlink_node( &m_Head, h.ptr(), &m_Head );
+ --m_ItemCounter;
h->m_Lock.unlock();
m_Head.m_Lock.unlock();
- retire_node( h.ptr() ) ; // free node
+ retire_node( h.ptr()) ; // free node
}
}
}
this function always returns 0.
@note Even if you use real item counter and it returns 0, this fact does not mean that the list
- is empty. To check list emptyness use \p empty() method.
+ is empty. To check list emptiness use \p empty() method.
*/
size_t size() const
{
return m_ItemCounter.value();
}
+ /// Returns const reference to internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
protected:
//@cond
// split-list support
// Hack: convert node_type to value_type.
// In principle, auxiliary node cannot be reducible to value_type
// We assume that internal comparator can correctly distinguish aux and regular node.
- return insert_at( pHead, *node_traits::to_value_ptr( pNode ) );
+ return insert_at( pHead, *node_traits::to_value_ptr( pNode ));
}
bool insert_at( node_type * pHead, value_type& val )
{
- link_checker::is_empty( node_traits::to_node_ptr( val ) );
position pos;
key_comparator cmp;
while ( true ) {
- search( pHead, val, pos, key_comparator() );
+ search( pHead, val, pos, key_comparator());
{
- auto_lock_position alp( pos );
+ scoped_position_lock alp( pos );
if ( validate( pos.pPred, pos.pCur )) {
if ( pos.pCur != &m_Tail && cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 ) {
// failed: key already in list
+ m_Stat.onInsertFailed();
return false;
}
else {
link_node( node_traits::to_node_ptr( val ), pos.pPred, pos.pCur );
- ++m_ItemCounter;
- return true;
+ break;
}
}
}
+
+ m_Stat.onInsertRetry();
}
+
+ ++m_ItemCounter;
+ m_Stat.onInsertSuccess();
+ return true;
}
template <typename Func>
bool insert_at( node_type * pHead, value_type& val, Func f )
{
- link_checker::is_empty( node_traits::to_node_ptr( val ) );
position pos;
key_comparator cmp;
while ( true ) {
- search( pHead, val, pos, key_comparator() );
+ search( pHead, val, pos, key_comparator());
{
- auto_lock_position alp( pos );
+ scoped_position_lock alp( pos );
if ( validate( pos.pPred, pos.pCur )) {
if ( pos.pCur != &m_Tail && cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 ) {
// failed: key already in list
+ m_Stat.onInsertFailed();
return false;
}
else {
link_node( node_traits::to_node_ptr( val ), pos.pPred, pos.pCur );
f( val );
- ++m_ItemCounter;
- return true;
+ break;
}
}
}
+
+ m_Stat.onInsertRetry();
}
+
+ ++m_ItemCounter;
+ m_Stat.onInsertSuccess();
+ return true;
}
template <typename Func>
key_comparator cmp;
while ( true ) {
- search( pHead, val, pos, key_comparator() );
+ search( pHead, val, pos, key_comparator());
{
- auto_lock_position alp( pos );
+ scoped_position_lock alp( pos );
if ( validate( pos.pPred, pos.pCur )) {
if ( pos.pCur != &m_Tail && cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 ) {
// key already in the list
func( false, *node_traits::to_value_ptr( *pos.pCur ) , val );
+ m_Stat.onUpdateExisting();
return std::make_pair( true, false );
}
else {
// new key
- if ( !bAllowInsert )
+ if ( !bAllowInsert ) {
+ m_Stat.onUpdateFailed();
return std::make_pair( false, false );
-
- link_checker::is_empty( node_traits::to_node_ptr( val ) );
+ }
link_node( node_traits::to_node_ptr( val ), pos.pPred, pos.pCur );
func( true, val, val );
- ++m_ItemCounter;
- return std::make_pair( true, true );
+ break;
}
}
}
+
+ m_Stat.onUpdateRetry();
}
+
+ ++m_ItemCounter;
+ m_Stat.onUpdateNew();
+ return std::make_pair( true, true );
}
bool unlink_at( node_type * pHead, value_type& val )
key_comparator cmp;
while ( true ) {
- search( pHead, val, pos, key_comparator() );
+ search( pHead, val, pos, key_comparator());
{
int nResult = 0;
{
- auto_lock_position alp( pos );
- if ( validate( pos.pPred, pos.pCur ) ) {
+ scoped_position_lock alp( pos );
+ if ( validate( pos.pPred, pos.pCur )) {
if ( pos.pCur != &m_Tail
&& cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0
&& node_traits::to_value_ptr( pos.pCur ) == &val )
{
// item found
unlink_node( pos.pPred, pos.pCur, pHead );
- --m_ItemCounter;
nResult = 1;
}
else
nResult = -1;
}
}
+
if ( nResult ) {
if ( nResult > 0 ) {
+ --m_ItemCounter;
retire_node( pos.pCur );
+ m_Stat.onEraseSuccess();
return true;
}
+
+ m_Stat.onEraseFailed();
return false;
}
}
+
+ m_Stat.onEraseRetry();
}
}
{
int nResult = 0;
{
- auto_lock_position alp( pos );
+ scoped_position_lock alp( pos );
if ( validate( pos.pPred, pos.pCur )) {
if ( pos.pCur != &m_Tail && cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 ) {
// key found
unlink_node( pos.pPred, pos.pCur, pHead );
- f( *node_traits::to_value_ptr( *pos.pCur ) );
- --m_ItemCounter;
+ f( *node_traits::to_value_ptr( *pos.pCur ));
nResult = 1;
}
else {
}
if ( nResult ) {
if ( nResult > 0 ) {
+ --m_ItemCounter;
retire_node( pos.pCur );
+ m_Stat.onEraseSuccess();
return true;
}
+
+ m_Stat.onEraseFailed();
return false;
}
}
+
+ m_Stat.onEraseRetry();
}
}
{
position pos;
if ( erase_at( pHead, val, cmp, [](value_type const &){}, pos )) {
- gp.set( pos.guards.template get<value_type>(position::guard_current_item) );
+ gp.set( pos.guards.template get<value_type>(position::guard_current_item));
return true;
}
return false;
&& cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 )
{
f( *node_traits::to_value_ptr( *pos.pCur ), val );
+ m_Stat.onFindSuccess();
return true;
}
}
+
+ m_Stat.onFindFailed();
return false;
}
position pos;
search( pHead, val, pos, cmp );
- return pos.pCur != &m_Tail
- && !pos.pCur->is_marked()
- && cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0;
+ if ( pos.pCur != &m_Tail && !pos.pCur->is_marked() && cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 ) {
+ m_Stat.onFindSuccess();
+ return true;
+ }
+
+ m_Stat.onFindFailed();
+ return false;
}
template <typename Q, typename Compare>
&& cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 )
{
gp.set( pos.guards.template get<value_type>( position::guard_current_item ));
+ m_Stat.onFindSuccess();
return true;
}
+
+ m_Stat.onFindFailed();
return false;
}
template <typename Q, typename Compare>
void search( node_type * pHead, const Q& key, position& pos, Compare cmp )
{
- const node_type * pTail = &m_Tail;
+ node_type const* pTail = &m_Tail;
marked_node_ptr pCur( pHead );
marked_node_ptr pPrev( pHead );
- back_off bkoff;
-
- while ( pCur.ptr() != pTail )
- {
+ while ( pCur.ptr() != pTail ) {
if ( pCur.ptr() != pHead ) {
- if ( cmp( *node_traits::to_value_ptr( *pCur.ptr() ), key ) >= 0 )
+ if ( cmp( *node_traits::to_value_ptr( *pCur.ptr()), key ) >= 0 )
break;
}
pos.guards.copy( position::guard_prev_item, position::guard_current_item );
pPrev = pCur;
- for (;;) {
- pCur = pPrev->m_pNext.load(memory_model::memory_order_relaxed);
- pos.guards.assign( position::guard_current_item, node_traits::to_value_ptr( pCur.ptr() ));
- if ( pCur == pPrev->m_pNext.load(memory_model::memory_order_acquire) )
- break;
- bkoff();
- }
+ pCur = pos.guards.protect( position::guard_current_item, pPrev->m_pNext,
+ []( marked_node_ptr p ) { return node_traits::to_value_ptr( p.ptr()); }
+ );
assert( pCur.ptr() != nullptr );
+ if ( pCur.bits())
+ pPrev = pCur = pHead;
}
pos.pCur = pCur.ptr();
pos.pPred = pPrev.ptr();
}
- static bool validate( node_type * pPred, node_type * pCur )
+ bool validate( node_type * pPred, node_type * pCur ) CDS_NOEXCEPT
+ {
+ if ( validate_link( pPred, pCur )) {
+ m_Stat.onValidationSuccess();
+ return true;
+ }
+
+ m_Stat.onValidationFailed();
+ return false;
+ }
+
+ static bool validate_link( node_type * pPred, node_type * pCur ) CDS_NOEXCEPT
{
return !pPred->is_marked()
&& !pCur->is_marked()
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