-//$$CDS-header$$
+/*
+ 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.
+*/
#ifndef CDSLIB_URCU_DETAILS_GPB_H
#define CDSLIB_URCU_DETAILS_GPB_H
#include <mutex>
+#include <limits>
#include <cds/urcu/details/gp.h>
#include <cds/algo/backoff_strategy.h>
#include <cds/container/vyukov_mpmc_cycle_queue.h>
i.e. until the RCU quiescent state will come. After that the buffer and all retired objects are freed.
This synchronization cycle may be called in any thread that calls \p retire_ptr function.
- The \p Buffer contains items of \ref cds_urcu_retired_ptr "retired_ptr" type and it should support a queue interface with
+ The \p Buffer contains items of \ref cds_urcu_retired_ptr "epoch_retired_ptr" type and it should support a queue interface with
three function:
- <tt> bool push( retired_ptr& p ) </tt> - places the retired pointer \p p into queue. If the function
returns \p false it means that the buffer is full and RCU synchronization cycle must be processed.
this function must return \p false
- <tt>size_t size()</tt> - returns queue's item count.
- The buffer is considered as full if \p push returns \p false or the buffer size reaches the RCU threshold.
+ The buffer is considered as full if \p push() returns \p false or the buffer size reaches the RCU threshold.
There is a wrapper \ref cds_urcu_general_buffered_gc "gc<general_buffered>" for \p %general_buffered class
that provides unified RCU interface. You should use this wrapper class instead \p %general_buffered
Template arguments:
- - \p Buffer - buffer type. Default is cds::container::VyukovMPMCCycleQueue
+ - \p Buffer - buffer type. Default is \p cds::container::VyukovMPMCCycleQueue
- \p Lock - mutex type, default is \p std::mutex
- \p Backoff - back-off schema, default is cds::backoff::Default
*/
typedef base_class::thread_gc thread_gc ; ///< Thread-side RCU part
typedef typename thread_gc::scoped_lock scoped_lock ; ///< Access lock class
- static bool const c_bBuffered = true ; ///< This RCU buffers disposed elements
+ //@cond
+ static bool const c_bBuffered = true ; ///< Bufferized RCU
+ //@endcond
protected:
//@cond
protected:
//@cond
- buffer_type m_Buffer;
- atomics::atomic<uint64_t> m_nCurEpoch;
- lock_type m_Lock;
- size_t const m_nCapacity;
+ buffer_type m_Buffer;
+ atomics::atomic<uint64_t> m_nCurEpoch;
+ lock_type m_Lock;
+ size_t const m_nCapacity;
//@endcond
public:
/// Returns singleton instance
static general_buffered * instance()
{
- return static_cast<general_buffered *>( base_class::instance() );
+ return static_cast<general_buffered *>( base_class::instance());
}
/// Checks if the singleton is created and ready to use
static bool isUsed()
~general_buffered()
{
- clear_buffer( (uint64_t) -1 );
+ clear_buffer( std::numeric_limits< uint64_t >::max());
}
void flip_and_wait()
p.free();
}
else {
- push_buffer( p );
+ push_buffer( std::move(p));
break;
}
}
}
- // Return: true - synchronize has been called, false - otherwise
- bool push_buffer( epoch_retired_ptr& ep )
+ // Return: \p true - synchronize has been called, \p false - otherwise
+ bool push_buffer( epoch_retired_ptr&& ep )
{
bool bPushed = m_Buffer.push( ep );
- if ( !bPushed || m_Buffer.size() >= capacity() ) {
+ if ( !bPushed || m_Buffer.size() >= capacity()) {
synchronize();
if ( !bPushed ) {
ep.free();
/// Destroys singleton object
static void Destruct( bool bDetachAll = false )
{
- if ( isUsed() ) {
- instance()->clear_buffer( (uint64_t) -1 );
+ if ( isUsed()) {
+ instance()->clear_buffer( std::numeric_limits< uint64_t >::max());
if ( bDetachAll )
instance()->m_ThreadList.detach_all();
delete instance();
When the buffer becomes full \ref synchronize function is called
to wait for the end of grace period and then to free all pointers from the buffer.
*/
- virtual void retire_ptr( retired_ptr& p )
+ virtual void retire_ptr( retired_ptr& p ) override
{
- if ( p.m_p ) {
- epoch_retired_ptr ep( p, m_nCurEpoch.load( atomics::memory_order_relaxed ));
- push_buffer( ep );
- }
+ if ( p.m_p )
+ push_buffer( epoch_retired_ptr( p, m_nCurEpoch.load( atomics::memory_order_relaxed )));
}
/// Retires the pointer chain [\p itFirst, \p itLast)
while ( itFirst != itLast ) {
epoch_retired_ptr ep( *itFirst, nEpoch );
++itFirst;
- push_buffer( ep );
+ push_buffer( std::move(ep));
+ }
+ }
+
+ /// Retires the pointer chain until \p Func returns \p nullptr retired pointer
+ template <typename Func>
+ void batch_retire( Func e )
+ {
+ uint64_t nEpoch = m_nCurEpoch.load( atomics::memory_order_relaxed );
+ for ( retired_ptr p{ e() }; p.m_p; ) {
+ epoch_retired_ptr ep( p, nEpoch );
+ p = e();
+ push_buffer( std::move(ep));
}
}
bool synchronize( epoch_retired_ptr& ep )
{
uint64_t nEpoch;
- atomics::atomic_thread_fence( atomics::memory_order_acquire );
{
std::unique_lock<lock_type> sl( m_Lock );
- if ( ep.m_p && m_Buffer.push( ep ) )
+ if ( ep.m_p && m_Buffer.push( ep ))
return false;
nEpoch = m_nCurEpoch.fetch_add( 1, atomics::memory_order_relaxed );
flip_and_wait();
flip_and_wait();
}
clear_buffer( nEpoch );
- atomics::atomic_thread_fence( atomics::memory_order_release );
return true;
}
//@endcond
}
};
+ /// User-space general-purpose RCU with deferred (buffered) reclamation (stripped version)
+ /**
+ @headerfile cds/urcu/general_buffered.h
+
+ This short version of \p general_buffered is intended for stripping debug info.
+ If you use \p %general_buffered with default template arguments you may use
+ this stripped version. All functionality of both classes are identical.
+ */
+ class general_buffered_stripped: public general_buffered<>
+ {};
+
}} // namespace cds::urcu
#endif // #ifndef CDSLIB_URCU_DETAILS_GPB_H