Subject: [Boost-commit] svn:boost r52672 - sandbox/stm/boost/stm/detail
From: justin_at_[hidden]
Date: 2009-04-29 22:19:59
Author: jgottschlich
Date: 2009-04-29 22:19:58 EDT (Wed, 29 Apr 2009)
New Revision: 52672
URL: http://svn.boost.org/trac/boost/changeset/52672
Log:
new smart "read, write and upgradable" pointers for transactions.
Added:
sandbox/stm/boost/stm/detail/tx_ptr.hpp (contents, props changed)
Added: sandbox/stm/boost/stm/detail/tx_ptr.hpp
==============================================================================
--- (empty file)
+++ sandbox/stm/boost/stm/detail/tx_ptr.hpp 2009-04-29 22:19:58 EDT (Wed, 29 Apr 2009)
@@ -0,0 +1,165 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Justin E. Gottchlich 2009.
+// (C) Copyright Vicente J. Botet Escriba 2009.
+// Distributed under the Boost
+// Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or
+// copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/synchro for documentation.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+#ifndef BOOST_STM_TX_PTR__HPP
+#define BOOST_STM_TX_PTR__HPP
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+#include <boost/stm/transaction.hpp>
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+namespace boost { namespace stm {
+
+template <typename T>
+class tx_rd_ptr
+{
+public:
+
+ tx_rd_ptr(transaction &t, T const &tx_obj) :
+ t_(t), tx_ptr_(&const_cast<T&>(t_.read(tx_obj))), written_(false)
+ {}
+
+ T* get() const
+ {
+ if (t_.forced_to_abort())
+ {
+ t_.lock_and_abort();
+ throw aborted_transaction_exception("aborting transaction");
+ }
+
+ // we are already holding the written object
+ if (written_) return tx_ptr_;
+
+ T* temp = t_.get_written(*tx_ptr_);
+
+ // if we found something, store this as the tx_ptr_
+ if (0 != temp)
+ {
+ tx_ptr_ = temp;
+ written_ = true;
+ }
+
+ return tx_ptr_;
+ }
+
+ T const & operator*() const { return *get(); }
+ T const * operator->() const { return get(); }
+
+private:
+
+ mutable transaction &t_;
+ mutable T *tx_ptr_;
+ mutable bool written_;
+};
+
+template <typename T>
+class tx_wr_ptr;
+
+template <typename T>
+class tx_upgrd_ptr
+{
+public:
+
+ tx_upgrd_ptr(transaction &t, T & tx_obj) :
+ t_(t), tx_obj_(const_cast<T&>(t_.read(tx_obj))), upgraded_(false)
+ {}
+
+ const T* get()
+ {
+ if (t_.forced_to_abort())
+ {
+ t_.lock_and_abort();
+ throw aborted_transaction_exception("aborting transaction");
+ }
+ if (!upgraded_) {
+ T &new_tx_obj_=const_cast<T&>(t_.read(tx_obj_));
+ if (&new_tx_obj_!=&tx_obj_) {
+ tx_obj_=new_tx_obj_;
+ upgraded_=true;
+ }
+ }
+ return &tx_obj_;
+ }
+
+ const T& operator*()
+ {
+ return *get();
+ }
+
+ const T* operator->()
+ {
+ return get();
+ }
+
+
+ T& upgrade() {
+ tx_obj_=t_.write(tx_obj_);
+ upgraded_=true;
+ return tx_obj_;
+ }
+
+private:
+ //template <typename TT>
+ friend class tx_wr_ptr;
+
+ mutable transaction &t_;
+ mutable T &tx_obj_;
+ bool upgraded_;
+};
+
+
+template <typename T>
+class tx_wr_ptr
+{
+public:
+
+ tx_wr_ptr(transaction &t, T & tx_obj) :
+ t_(t), tx_obj_(t_.write(tx_obj))
+ {}
+
+ tx_wr_ptr(tx_upgrd_ptr<T> &upgrd) :
+ t_(upgrd.t_), tx_obj_(upgrd.upgrade())
+ {}
+
+ T& operator*()
+ {
+ if (t_.forced_to_abort())
+ {
+ t_.lock_and_abort();
+ throw aborted_transaction_exception("aborting transaction");
+ }
+ return tx_obj_;
+ }
+
+ T* operator->()
+ {
+ if (t_.forced_to_abort())
+ {
+ t_.lock_and_abort();
+ throw aborted_transaction_exception("aborting transaction");
+ }
+ return &tx_obj_;
+ }
+
+private:
+ mutable boost::stm::transaction &t_;
+ mutable T &tx_obj_;
+};
+
+
+}}
+#endif
+
+