-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
+
+ 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.
+*/
/*
File: hzp_gc.cpp
scan_type nScanType
)
: m_pListHead( nullptr )
- ,m_bStatEnabled( true )
+ ,m_bStatEnabled( false )
,m_nHazardPointerCount( nHazardPtrCount == 0 ? c_nHazardPointerPerThread : nHazardPtrCount )
,m_nMaxThreadCount( nMaxThreadCount == 0 ? c_nMaxThreadCount : nMaxThreadCount )
,m_nMaxRetiredPtrCount( nMaxRetiredPtrCount > c_nMaxRetireNodeCount ? nMaxRetiredPtrCount : c_nMaxRetireNodeCount )
for ( hplist_node * hprec = pHead; hprec; hprec = pNext ) {
assert( hprec->m_idOwner.load( atomics::memory_order_relaxed ) == nullThreadId
|| hprec->m_idOwner.load( atomics::memory_order_relaxed ) == mainThreadId
- || !cds::OS::is_thread_alive( hprec->m_idOwner.load( atomics::memory_order_relaxed ) )
+ || !cds::OS::is_thread_alive( hprec->m_idOwner.load( atomics::memory_order_relaxed ))
);
details::retired_vector& vect = hprec->m_arrRetired;
details::retired_vector::iterator itRetired = vect.begin();
++itRetired;
}
vect.clear();
- pNext = hprec->m_pNextNode;
+ pNext = hprec->m_pNextNode.load( atomics::memory_order_relaxed );
hprec->m_bFree.store( true, atomics::memory_order_relaxed );
DeleteHPRec( hprec );
}
}
- inline GarbageCollector::hplist_node * GarbageCollector::NewHPRec()
+ inline GarbageCollector::hplist_node * GarbageCollector::NewHPRec( OS::ThreadId owner )
{
CDS_HAZARDPTR_STATISTIC( ++m_Stat.m_AllocNewHPRec )
- return new hplist_node( *this );
+ return new hplist_node( *this, owner );
}
inline void GarbageCollector::DeleteHPRec( hplist_node * pNode )
const cds::OS::ThreadId curThreadId = cds::OS::get_current_thread_id();
// First try to reuse a retired (non-active) HP record
- for ( hprec = m_pListHead.load( atomics::memory_order_acquire ); hprec; hprec = hprec->m_pNextNode ) {
+ for ( hprec = m_pListHead.load( atomics::memory_order_relaxed ); hprec; hprec = hprec->m_pNextNode.load( atomics::memory_order_relaxed )) {
cds::OS::ThreadId thId = nullThreadId;
- if ( !hprec->m_idOwner.compare_exchange_strong( thId, curThreadId, atomics::memory_order_seq_cst, atomics::memory_order_relaxed ) )
+ if ( !hprec->m_idOwner.compare_exchange_strong( thId, curThreadId, atomics::memory_order_acquire, atomics::memory_order_relaxed ))
continue;
- hprec->m_bFree.store( false, atomics::memory_order_release );
+ hprec->m_bFree.store( false, atomics::memory_order_relaxed );
return hprec;
}
// No HP records available for reuse
// Allocate and push a new HP record
- hprec = NewHPRec();
- hprec->m_idOwner.store( curThreadId, atomics::memory_order_relaxed );
- hprec->m_bFree.store( false, atomics::memory_order_relaxed );
+ hprec = NewHPRec( curThreadId );
- atomics::atomic_thread_fence( atomics::memory_order_release );
-
- hplist_node * pOldHead = m_pListHead.load( atomics::memory_order_acquire );
+ hplist_node * pOldHead = m_pListHead.load( atomics::memory_order_relaxed );
do {
- hprec->m_pNextNode = pOldHead;
- } while ( !m_pListHead.compare_exchange_weak( pOldHead, hprec, atomics::memory_order_release, atomics::memory_order_relaxed ));
+ hprec->m_pNextNode.store( pOldHead, atomics::memory_order_relaxed );
+ } while ( !m_pListHead.compare_exchange_weak( pOldHead, hprec, atomics::memory_order_acq_rel, atomics::memory_order_acquire ));
return hprec;
}
{
hplist_node * pNext = nullptr;
const cds::OS::ThreadId nullThreadId = cds::OS::c_NullThreadId;
- for ( hplist_node * hprec = m_pListHead.load(atomics::memory_order_acquire); hprec; hprec = pNext ) {
- pNext = hprec->m_pNextNode;
+ for ( hplist_node * hprec = m_pListHead.load(atomics::memory_order_relaxed); hprec; hprec = pNext ) {
+ pNext = hprec->m_pNextNode.load( atomics::memory_order_relaxed );
if ( hprec->m_idOwner.load(atomics::memory_order_relaxed) != nullThreadId ) {
free_hp_record( hprec );
}
// Stage 1: Scan HP list and insert non-null values in plist
- hplist_node * pNode = m_pListHead.load(atomics::memory_order_acquire);
+ hplist_node * pNode = m_pListHead.load(atomics::memory_order_relaxed);
while ( pNode ) {
for ( size_t i = 0; i < m_nHazardPointerCount; ++i ) {
- void * hptr = pNode->m_hzp[i];
+ pRec->sync();
+ void * hptr = pNode->m_hzp[i].get();
if ( hptr )
plist.push_back( hptr );
}
- pNode = pNode->m_pNextNode;
+ pNode = pNode->m_pNextNode.load( atomics::memory_order_relaxed );
}
// Sort plist to simplify search in
- std::sort( plist.begin(), plist.end() );
+ std::sort( plist.begin(), plist.end());
// Stage 2: Search plist
details::retired_vector& arrRetired = pRec->m_arrRetired;
std::vector< void * >::iterator itEnd = plist.end();
size_t nDeferredCount = 0;
while ( itRetired != itRetiredEnd ) {
- if ( std::binary_search( itBegin, itEnd, itRetired->m_p ) ) {
+ if ( std::binary_search( itBegin, itEnd, itRetired->m_p )) {
arrRetired.push( *itRetired );
++nDeferredCount;
}
*/
// Search guarded pointers in retired array
- hplist_node * pNode = m_pListHead.load( atomics::memory_order_acquire );
+ hplist_node * pNode = m_pListHead.load( atomics::memory_order_relaxed );
{
details::retired_ptr dummyRetired;
while ( pNode ) {
- if ( !pNode->m_bFree.load( atomics::memory_order_acquire ) ) {
+ if ( !pNode->m_bFree.load( atomics::memory_order_relaxed )) {
for ( size_t i = 0; i < m_nHazardPointerCount; ++i ) {
- void * hptr = pNode->m_hzp[i];
+ pRec->sync();
+ void * hptr = pNode->m_hzp[i].get();
if ( hptr ) {
dummyRetired.m_p = hptr;
details::retired_vector::iterator it = std::lower_bound( itRetired, itRetiredEnd, dummyRetired, cds::gc::details::retired_ptr::less );
}
}
}
- pNode = pNode->m_pNextNode;
+ pNode = pNode->m_pNextNode.load( atomics::memory_order_relaxed );
}
}
{
CDS_HAZARDPTR_STATISTIC( ++m_Stat.m_HelpScanCallCount )
- assert( static_cast<hplist_node *>(pThis)->m_idOwner.load(atomics::memory_order_relaxed) == cds::OS::get_current_thread_id() );
+ assert( static_cast<hplist_node *>(pThis)->m_idOwner.load(atomics::memory_order_relaxed) == cds::OS::get_current_thread_id());
const cds::OS::ThreadId nullThreadId = cds::OS::c_NullThreadId;
const cds::OS::ThreadId curThreadId = cds::OS::get_current_thread_id();
- for ( hplist_node * hprec = m_pListHead.load(atomics::memory_order_acquire); hprec; hprec = hprec->m_pNextNode ) {
+ for ( hplist_node * hprec = m_pListHead.load(atomics::memory_order_relaxed); hprec; hprec = hprec->m_pNextNode.load( atomics::memory_order_relaxed )) {
// If m_bFree == true then hprec->m_arrRetired is empty - we don't need to see it
- if ( hprec->m_bFree.load(atomics::memory_order_acquire) )
+ if ( hprec->m_bFree.load(atomics::memory_order_relaxed))
continue;
// Owns hprec if it is empty.
// Several threads may work concurrently so we use atomic technique only.
{
- cds::OS::ThreadId curOwner = hprec->m_idOwner.load(atomics::memory_order_acquire);
+ cds::OS::ThreadId curOwner = hprec->m_idOwner.load(atomics::memory_order_relaxed);
if ( curOwner == nullThreadId || !cds::OS::is_thread_alive( curOwner )) {
- if ( !hprec->m_idOwner.compare_exchange_strong( curOwner, curThreadId, atomics::memory_order_release, atomics::memory_order_relaxed ))
- continue;
- }
- else {
- curOwner = nullThreadId;
- if ( !hprec->m_idOwner.compare_exchange_strong( curOwner, curThreadId, atomics::memory_order_release, atomics::memory_order_relaxed ))
+ if ( !hprec->m_idOwner.compare_exchange_strong( curOwner, curThreadId, atomics::memory_order_acquire, atomics::memory_order_relaxed ))
continue;
}
+ else
+ continue;
+ //else {
+ // curOwner = nullThreadId;
+ // if ( !hprec->m_idOwner.compare_exchange_strong( curOwner, curThreadId, atomics::memory_order_acquire, atomics::memory_order_relaxed ))
+ // continue;
+ //}
}
// We own the thread successfully. Now, we can see whether hp_record has retired pointers.
details::retired_vector& dest = pThis->m_arrRetired;
assert( !dest.isFull());
details::retired_vector::iterator itRetired = src.begin();
+
+ // TSan can issue a warning here:
+ // read src.m_nSize in src.end()
+ // write src.m_nSize in src.clear()
+ // This is false positive since we own hprec
+ CDS_TSAN_ANNOTATE_IGNORE_READS_BEGIN;
details::retired_vector::iterator itRetiredEnd = src.end();
+ CDS_TSAN_ANNOTATE_IGNORE_READS_END;
+
while ( itRetired != itRetiredEnd ) {
dest.push( *itRetired );
if ( dest.isFull()) {
}
++itRetired;
}
+
+ // TSan: write src.m_nSize, see a comment above
+ CDS_TSAN_ANNOTATE_IGNORE_WRITES_BEGIN;
src.clear();
+ CDS_TSAN_ANNOTATE_IGNORE_WRITES_END;
- hprec->m_bFree.store(true, atomics::memory_order_release);
+ hprec->m_bFree.store(true, atomics::memory_order_relaxed);
hprec->m_idOwner.store( nullThreadId, atomics::memory_order_release );
Scan( pThis );
stat.nTotalRetiredPtrCount =
stat.nRetiredPtrInFreeHPRecs = 0;
- for ( hplist_node * hprec = m_pListHead.load(atomics::memory_order_acquire); hprec; hprec = hprec->m_pNextNode ) {
+ for ( hplist_node * hprec = m_pListHead.load(atomics::memory_order_relaxed); hprec; hprec = hprec->m_pNextNode.load( atomics::memory_order_relaxed )) {
++stat.nHPRecAllocated;
stat.nTotalRetiredPtrCount += hprec->m_arrRetired.size();
- if ( hprec->m_bFree.load(atomics::memory_order_relaxed) ) {
+ if ( hprec->m_bFree.load(atomics::memory_order_relaxed)) {
// Free HP record
stat.nRetiredPtrInFreeHPRecs += hprec->m_arrRetired.size();
}
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