[Boost-commit] svn:boost r52672 - sandbox/stm/boost/stm/detail

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
+
+