-//$$CDS-header$$
+/*
+ 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_MICHAEL_LIST_RCU_H
#define CDSLIB_INTRUSIVE_MICHAEL_LIST_RCU_H
#include <cds/details/make_const_type.h>
#include <cds/urcu/exempt_ptr.h>
#include <cds/urcu/raw_ptr.h>
+#include <cds/intrusive/details/raw_ptr_disposer.h>
namespace cds { namespace intrusive {
typedef cds::urcu::gc< RCU > gc; ///< Garbage collector
typedef Tag tag; ///< tag
- typedef cds::details::marked_ptr<node, 1> marked_ptr ; ///< marked pointer
- typedef typename gc::template atomic_marked_ptr< marked_ptr> atomic_marked_ptr ; ///< atomic marked pointer specific for GC
+ typedef cds::details::marked_ptr<node, 3> marked_ptr; ///< marked pointer
+ typedef typename gc::template atomic_marked_ptr<marked_ptr> atomic_marked_ptr; ///< atomic marked pointer specific for GC
- atomic_marked_ptr m_pNext ; ///< pointer to the next node in the container
+ atomic_marked_ptr m_pNext; ///< pointer to the next node in the container
node * m_pDelChain; ///< Deleted node chain (local for a thread)
CDS_CONSTEXPR node() CDS_NOEXCEPT
static void clear_links( node_type * pNode )
{
- pNode->m_pNext.store( marked_node_ptr(), memory_model::memory_order_relaxed );
+ pNode->m_pNext.store( marked_node_ptr(), memory_model::memory_order_release );
pNode->m_pDelChain = nullptr;
}
auto f = [&pChain]() -> cds::urcu::retired_ptr {
node_type * p = pChain;
- pChain = p->m_pDelChain;
- return cds::urcu::make_retired_ptr<clear_and_dispose>( node_traits::to_value_ptr( p ));
+ if ( p ) {
+ pChain = p->m_pDelChain;
+ return cds::urcu::make_retired_ptr<clear_and_dispose>( node_traits::to_value_ptr( p ));
+ }
+ return cds::urcu::make_retired_ptr<clear_and_dispose>( static_cast<value_type *>(nullptr));
};
gc::batch_retire(std::ref(f));
}
private:
//@cond
- struct raw_ptr_disposer
- {
- node_type * pReclaimedChain;
-
- raw_ptr_disposer()
- : pReclaimedChain( nullptr )
- {}
-
- raw_ptr_disposer( position& pos )
- : pReclaimedChain( pos.pDelChain )
- {
- pos.pDelChain = nullptr;
- }
-
- raw_ptr_disposer( raw_ptr_disposer&& d )
- : pReclaimedChain( d.pReclaimedChain )
- {
- d.pReclaimedChain = nullptr;
- }
-
- raw_ptr_disposer( raw_ptr_disposer const& ) = delete;
-
- ~raw_ptr_disposer()
- {
- apply();
- }
-
- void apply()
+ struct chain_disposer {
+ void operator()( node_type * pChain ) const
{
- if ( pReclaimedChain ) {
- dispose_chain( pReclaimedChain );
- pReclaimedChain = nullptr;
- }
+ dispose_chain( pChain );
}
};
+ typedef cds::intrusive::details::raw_ptr_disposer< gc, node_type, chain_disposer> raw_ptr_disposer;
//@endcond
public:
/// Result of \p get(), \p get_with() functions - pointer to the node found
- typedef cds::urcu::raw_ptr< gc, value_type, raw_ptr_disposer > raw_ptr;
+ typedef cds::urcu::raw_ptr< gc, value_type, raw_ptr_disposer > raw_ptr;
protected:
//@cond
bool unlink_node( position& pos, erase_node_mask nMask )
{
+ assert(gc::is_locked() );
+
// Mark the node (logical deletion)
marked_node_ptr next(pos.pNext, 0);
- if ( pos.pCur->m_pNext.compare_exchange_strong( next, next | nMask, memory_model::memory_order_acq_rel, atomics::memory_order_relaxed )) {
+ if ( pos.pCur->m_pNext.compare_exchange_strong( next, next | nMask, memory_model::memory_order_release, atomics::memory_order_relaxed )) {
// Try physical removal - fast path
marked_node_ptr cur(pos.pCur);
- if ( pos.pPrev->compare_exchange_strong(cur, marked_node_ptr(pos.pNext), memory_model::memory_order_acquire, atomics::memory_order_relaxed) ) {
+ if ( pos.pPrev->compare_exchange_strong(cur, marked_node_ptr(pos.pNext), memory_model::memory_order_acquire, atomics::memory_order_relaxed )) {
if ( nMask == erase_mask )
link_to_remove_chain( pos, pos.pCur );
}
return insert_at( m_pHead, val, f );
}
- /// Ensures that the \p item exists in the list
+ /// Updates the item
/**
The operation performs inserting or changing data with lock-free manner.
- If the item \p val not found in the list, then \p val is inserted into the list.
+ If the item \p val not found in the list, then \p val is inserted into the list
+ iff \p bAllowInsert is \p true.
Otherwise, the functor \p func is called with item found.
The functor signature is:
\code
with arguments:
- \p bNew - \p true if the item has been inserted, \p false otherwise
- \p item - item of the list
- - \p val - argument \p val passed into the \p ensure function
+ - \p val - argument \p val passed into the \p update() function
If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
refer to the same thing.
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.
- 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
+ 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 list.
The function makes RCU lock internally.
@warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
*/
template <typename Func>
+ std::pair<bool, bool> update( value_type& val, Func func, bool bAllowInsert = true )
+ {
+ return update_at( m_pHead, val, func, bAllowInsert );
+ }
+ //@cond
+ template <typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
std::pair<bool, bool> ensure( value_type& val, Func func )
{
- return ensure_at( m_pHead, val, func );
+ return update( val, func, true );
}
+ //@endcond
/// Unlinks the item \p val from the list
/**
The function searches the item \p val in the list and unlink it from the list
if it is found and it is equal to \p val.
- Difference between \ref erase and \p unlink functions: \p erase finds <i>a key</i>
- and deletes the item found. \p unlink finds an item by key and deletes it
+ Difference between \p erase() and \p %unlink() functions: \p %erase() finds <i>a key</i>
+ and deletes the item found. \p %unlink() finds an item by key and deletes it
only if \p val is an item of that list, i.e. the pointer to the item found
is equal to <tt> &val </tt>.
RCU \p synchronize method can be called.
Note that depending on RCU type used the \ref disposer call can be deferred.
+ \p disposer specified in \p Traits is called for unlinked item.
+
The function can throw cds::urcu::rcu_deadlock exception if deadlock is encountered and
deadlock checking policy is opt::v::rcu_throw_deadlock.
*/
}
/// Deletes the item from the list
- /** \anchor cds_intrusive_MichaelList_rcu_erase_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.
RCU \p synchronize method can be called.
Note that depending on RCU type used the \ref disposer call can be deferred.
+ \p disposer specified in \p Traits is called for deleted item.
+
The function can throw \ref cds_urcu_rcu_deadlock "cds::urcu::rcu_deadlock" exception if a deadlock is detected and
the deadlock checking policy is \p opt::v::rcu_throw_deadlock.
*/
/// Deletes the item from the list using \p pred predicate for searching
/**
- The function is an analog of \ref cds_intrusive_MichaelList_rcu_erase_val "erase(Q const&)"
+ The function is an analog of \p erase(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 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 )
}
/// Deletes the item from the list
- /** \anchor cds_intrusive_MichaelList_rcu_erase_func
+ /**
The function searches an item with key equal to \p key in the list,
call \p func functor with item found, unlinks it from the list, and returns \p true.
The \p Func interface is
RCU \p synchronize method can be called.
Note that depending on RCU type used the \ref disposer call can be deferred.
+ \p disposer specified in \p Traits is called for deleted item.
+
The function can throw \ref cds_urcu_rcu_deadlock "cds::urcu::rcu_deadlock" exception if a deadlock is detected and
the deadlock checking policy is \p opt::v::rcu_throw_deadlock.
*/
/// Deletes the item from the list using \p pred predicate for searching
/**
- The function is an analog of \ref cds_intrusive_MichaelList_rcu_erase_func "erase(Q const&, Func)"
+ The function is an analog of \p erase(Q const&, 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( Q const& key, Less pred, Func func )
/// Extracts an item from the list
/**
- @anchor cds_intrusive_MichaelList_rcu_extract
The function searches an item with key equal to \p key in the list,
unlinks it from the list, and returns \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the item found.
If \p key is not found the function returns an empty \p exempt_ptr.
@note The function does NOT dispose the item found. It just unlinks the item from the list
and returns a pointer to item found.
- You shouldn't lock RCU before calling this function, and you should manually release
- \p dest exempt pointer outside the RCU lock before reusing the pointer.
+ You shouldn't lock RCU for current thread before calling this function, and you should manually release
+ the returned exempt pointer before reusing it.
\code
#include <cds/urcu/general_buffered.h>
}
/// Find the key \p val
- /** \anchor cds_intrusive_MichaelList_rcu_find_func
+ /**
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:
/// Finds \p key using \p pred predicate for searching
/**
- The function is an analog of \ref cds_intrusive_MichaelList_rcu_find_func "find(Q&, Func)"
+ The function is an analog of \p find(Q&, 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.
}
//@endcond
- /// Finds \p key
- /** \anchor cds_intrusive_MichaelList_rcu_find_val
+ /// Checks whether the list contains \p key
+ /**
The function searches the item with key equal to \p key
- and returns \p true if \p val found or \p false otherwise.
+ and returns \p true if it is found, and \p false otherwise.
*/
template <typename Q>
- bool find( Q const& key )
+ bool contains( Q const& key )
{
return find_at( m_pHead, key, key_comparator() );
}
+ //@cond
+ template <typename Q>
+ CDS_DEPRECATED("deprecated, use contains()")
+ bool find( Q const& key )
+ {
+ return contains( key );
+ }
+ //@endcond
- /// Finds \p key 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_intrusive_MichaelList_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 pred must imply the same element order as the comparator used for building the list.
+ \p Less must imply the same element order as the comparator used for building the list.
*/
template <typename Q, typename Less>
- bool find_with( Q const& key, Less pred )
+ bool contains( Q const& key, Less pred )
{
CDS_UNUSED( pred );
return find_at( m_pHead, key, cds::opt::details::make_comparator_from_less<Less>() );
}
+ //@cond
+ template <typename Q, typename Less>
+ CDS_DEPRECATED("deprecated, use contains()")
+ bool find_with( Q const& key, Less pred )
+ {
+ return contains( key, pred );
+ }
+ //@endcond
/// Finds \p key and return the item found
/** \anchor cds_intrusive_MichaelList_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 nullptr.
+ If \p key is not found it returns empty \p raw_ptr object.
Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
typedef cds::intrusive::MichaelList< cds::urcu::gc< cds::urcu::general_buffered<> >, foo, my_traits > ord_list;
ord_list theList;
// ...
+ typename ord_list::raw_ptr rp;
{
// Lock RCU
ord_list::rcu_lock lock;
- foo * pVal = theList.get( 5 );
- if ( pVal ) {
- // Deal with pVal
+ rp = theList.get( 5 );
+ if ( rp ) {
+ // Deal with rp
//...
}
// Unlock RCU by rcu_lock destructor
- // pVal can be retired by disposer at any time after RCU has been unlocked
+ // Node owned by rp can be retired by disposer at any time after RCU has been unlocked
}
+ // You can manually release rp after RCU-locked section
+ rp.release();
\endcode
*/
template <typename Q>
}
template <typename Func>
- std::pair<iterator, bool> ensure_at_( atomic_node_ptr& refHead, value_type& val, Func func )
+ std::pair<iterator, bool> update_at_( atomic_node_ptr& refHead, value_type& val, Func func, bool bInsert )
{
position pos( refHead );
{
rcu_lock l;
- return ensure_at_locked( pos, val, func );
+ return update_at_locked( pos, val, func, bInsert );
}
}
template <typename Func>
- std::pair<bool, bool> ensure_at( atomic_node_ptr& refHead, value_type& val, Func func )
+ std::pair<bool, bool> update_at( atomic_node_ptr& refHead, value_type& val, Func func, bool bInsert )
{
position pos( refHead );
{
rcu_lock l;
- std::pair<iterator, bool> ret = ensure_at_locked( pos, val, func );
+ std::pair<iterator, bool> ret = update_at_locked( pos, val, func, bInsert );
return std::make_pair( ret.first != end(), ret.second );
}
}
back_off bkoff;
check_deadlock_policy::check();
+ node_type * pDel;
for (;;) {
{
rcu_lock l;
if ( !search( pos.refHead, val, pos, cmp ) )
return false;
+ // store pCur since it may be changed by unlink_node() slow path
+ pDel = pos.pCur;
if ( !unlink_node( pos, erase_mask )) {
bkoff();
continue;
}
}
-
- f( *node_traits::to_value_ptr( *pos.pCur ) );
+ assert( pDel );
+ f( *node_traits::to_value_ptr( pDel ) );
--m_ItemCounter;
return true;
}
back_off bkoff;
assert( !gc::is_locked() ) ; // RCU must not be locked!!!
+ node_type * pExtracted;
{
rcu_lock l;
for (;;) {
if ( !search( refHead, val, pos, cmp ) )
return nullptr;
+ // store pCur since it may be changed by unlink_node() slow path
+ pExtracted = pos.pCur;
if ( !unlink_node( pos, extract_mask )) {
bkoff();
continue;
}
--m_ItemCounter;
- return node_traits::to_value_ptr( pos.pCur );
+ value_type * pRet = node_traits::to_value_ptr( pExtracted );
+ assert( pExtracted->m_pDelChain == nullptr );
+ return pRet;
}
}
}
pNext = pCur->m_pNext.load(memory_model::memory_order_acquire);
- if ( pPrev->load(memory_model::memory_order_relaxed) != pCur
- || pNext != pCur->m_pNext.load(memory_model::memory_order_relaxed))
+ if ( pPrev->load(memory_model::memory_order_acquire) != pCur
+ || pNext != pCur->m_pNext.load(memory_model::memory_order_acquire))
{
bkoff();
goto try_again;
}
template <typename Func>
- std::pair<iterator, bool> ensure_at_locked( position& pos, value_type& val, Func func )
+ std::pair<iterator, bool> update_at_locked( position& pos, value_type& val, Func func, bool bInsert )
{
- // RCU lock should be locked!!!
+ // RCU should be locked!!!
assert( gc::is_locked() );
while ( true ) {
return std::make_pair( iterator( pos.pCur ), false );
}
else {
+ if ( !bInsert )
+ return std::make_pair( end(), false );
+
link_checker::is_empty( node_traits::to_node_ptr( val ) );
if ( link_node( node_traits::to_node_ptr( val ), pos ) ) {
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