--- /dev/null
+/*
+ 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_GPI_H
+#define CDSLIB_URCU_DETAILS_GPI_H
+
+#include <mutex>
+#include <cds/urcu/details/gp.h>
+#include <cds/algo/backoff_strategy.h>
+
+namespace cds { namespace urcu {
+
+ /// User-space general-purpose RCU with immediate reclamation
+ /**
+ @headerfile cds/urcu/general_instant.h
+
+ This is simplest general-purpose RCU implementation. When a thread calls \ref retire_ptr function
+ the RCU \p synchronize function is called that waits until all reader/updater threads end up
+ their read-side critical sections, i.e. until the RCU quiescent state will come.
+ After that the retired object is freed immediately.
+ Thus, the implementation blocks for any retired object
+
+ There is a wrapper \ref cds_urcu_general_instant_gc "gc<general_instant>" for \p %general_instant class
+ that provides unified RCU interface. You should use this wrapper class instead \p %general_instant
+
+ Template arguments:
+ - \p Lock - mutex type, default is \p std::mutex
+ - \p Backoff - back-off schema, default is cds::backoff::Default
+ */
+ template <
+ class Lock = std::mutex
+ ,class Backoff = cds::backoff::Default
+ >
+ class general_instant: public details::gp_singleton< general_instant_tag >
+ {
+ //@cond
+ typedef details::gp_singleton< general_instant_tag > base_class;
+ //@endcond
+
+ public:
+ typedef general_instant_tag rcu_tag ; ///< RCU tag
+ typedef Lock lock_type ; ///< Lock type
+ typedef Backoff back_off ; ///< Back-off schema type
+
+ typedef typename base_class::thread_gc thread_gc ; ///< Thread-side RCU part
+ typedef typename thread_gc::scoped_lock scoped_lock ; ///< Access lock class
+
+ //@cond
+ static bool const c_bBuffered = false ; ///< No buffers
+ //@endcond
+
+ protected:
+ //@cond
+ typedef details::gp_singleton_instance< rcu_tag > singleton_ptr;
+ //@endcond
+
+ protected:
+ //@cond
+ lock_type m_Lock;
+ //@endcond
+
+ public:
+ /// Returns singleton instance
+ static general_instant * instance()
+ {
+ return static_cast<general_instant *>( base_class::instance());
+ }
+
+ /// Checks if the singleton is created and ready to use
+ static bool isUsed()
+ {
+ return singleton_ptr::s_pRCU != nullptr;
+ }
+
+ protected:
+ //@cond
+ general_instant()
+ {}
+
+ ~general_instant()
+ {}
+
+ void flip_and_wait()
+ {
+ back_off bkoff;
+ base_class::flip_and_wait( bkoff );
+ }
+ //@endcond
+
+ public:
+ /// Creates singleton object
+ static void Construct()
+ {
+ if ( !singleton_ptr::s_pRCU )
+ singleton_ptr::s_pRCU = new general_instant();
+ }
+
+ /// Destroys singleton object
+ static void Destruct( bool bDetachAll = false )
+ {
+ if ( isUsed()) {
+ if ( bDetachAll )
+ instance()->m_ThreadList.detach_all();
+ delete instance();
+ singleton_ptr::s_pRCU = nullptr;
+ }
+ }
+
+ public:
+ /// Retires \p p pointer
+ /**
+ The method calls \p synchronize() to wait for the end of grace period
+ and calls \p p disposer.
+ */
+ virtual void retire_ptr( retired_ptr& p ) override
+ {
+ synchronize();
+ if ( p.m_p )
+ p.free();
+ }
+
+ /// Retires the pointer chain [\p itFirst, \p itLast)
+ template <typename ForwardIterator>
+ void batch_retire( ForwardIterator itFirst, ForwardIterator itLast )
+ {
+ if ( itFirst != itLast ) {
+ synchronize();
+ while ( itFirst != itLast ) {
+ retired_ptr p( *itFirst );
+ ++itFirst;
+ if ( p.m_p )
+ p.free();
+ }
+ }
+ }
+
+ /// Retires the pointer chain until \p Func returns \p nullptr retired pointer
+ template <typename Func>
+ void batch_retire( Func e )
+ {
+ retired_ptr p{ e() };
+ if ( p.m_p ) {
+ synchronize();
+ while ( p.m_p ) {
+ retired_ptr pr( p );
+ p = e();
+ pr.free();
+ }
+ }
+ }
+
+ /// Waits to finish a grace period
+ void synchronize()
+ {
+ assert( !thread_gc::is_locked());
+ std::unique_lock<lock_type> sl( m_Lock );
+ flip_and_wait();
+ flip_and_wait();
+ }
+
+ //@cond
+ // Added for uniformity
+ size_t constexpr capacity() const
+ {
+ return 1;
+ }
+ //@endcond
+ };
+
+ /// User-space general-purpose RCU with immediate reclamation (stripped version)
+ /**
+ @headerfile cds/urcu/general_instant.h
+
+ This short version of \p general_instant is intended for stripping debug info.
+ If you use \p %general_instant with default template arguments you may use
+ this stripped version. All functionality of both classes are identical.
+ */
+ class general_instant_stripped: public general_instant<>
+ {};
+
+}} // namespace cds::urcu
+
+#endif // #ifndef CDSLIB_URCU_DETAILS_GPI_H