From 2636e266dc7a048e52b40b668c460c2793e897c4 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Wed, 18 Aug 2010 20:02:11 +0200
Subject: Move shared_ptr to the details namespace

---
 odb/details/shared-ptr/base.txx | 206 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 206 insertions(+)
 create mode 100644 odb/details/shared-ptr/base.txx

(limited to 'odb/details/shared-ptr/base.txx')

diff --git a/odb/details/shared-ptr/base.txx b/odb/details/shared-ptr/base.txx
new file mode 100644
index 0000000..fc30fdf
--- /dev/null
+++ b/odb/details/shared-ptr/base.txx
@@ -0,0 +1,206 @@
+// file      : odb/details/shared-ptr/base.txx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009-2010 Code Synthesis Tools CC
+// license   : GNU GPL v2; see accompanying LICENSE file
+
+#include <odb/details/meta/answer.hxx>
+#include <odb/details/meta/polymorphic-p.hxx>
+
+namespace odb
+{
+  namespace details
+  {
+    namespace bits
+    {
+      // Support for locating the counter in the memory block.
+      //
+      template <typename X, bool poly = meta::polymorphic_p<X>::r>
+      struct locator;
+
+      template <typename X>
+      struct locator<X, false>
+      {
+        static std::size_t*
+        counter (X* x)
+        {
+          std::size_t* p (reinterpret_cast<std::size_t*> (x));
+
+          if (*(--p) != 0xDEADBEEF)
+            throw not_shared ();
+
+          return --p;
+        }
+      };
+
+      template <typename X>
+      struct locator<X, true>
+      {
+        static std::size_t*
+        counter (X* x)
+        {
+          std::size_t* p (
+            static_cast<std::size_t*> (
+              dynamic_cast<void*> (x)));
+
+          if (*(--p) != 0xDEADBEEF)
+            throw not_shared ();
+
+          return --p;
+        }
+      };
+
+      template <typename X>
+      std::size_t*
+      counter (const X* p)
+      {
+        return bits::locator<X>::counter (const_cast<X*> (p));
+      }
+
+      // Counter type and operations.
+      //
+      meta::no test (...);
+      meta::yes test (shared_base*);
+
+      template <typename X,
+                std::size_t A = sizeof (bits::test (reinterpret_cast<X*> (0)))>
+      struct counter_type;
+
+      template <typename X>
+      struct counter_type<X, sizeof (meta::no)>
+      {
+        typedef X r;
+      };
+
+      template <typename X>
+      struct counter_type<X, sizeof (meta::yes)>
+      {
+        typedef shared_base r;
+      };
+
+      template <typename X, typename Y>
+      struct counter_ops;
+
+      template <typename X>
+      struct counter_ops<X, X>
+      {
+        counter_ops (const X* p) : counter_ (p ? bits::counter (p) : 0) {}
+        counter_ops (const counter_ops& x) : counter_ (x.counter_) {}
+
+        template <typename Z>
+        counter_ops (const counter_ops<Z, Z>& x) : counter_ (x.counter_) {}
+
+        counter_ops&
+        operator= (const counter_ops& x)
+        {
+          counter_ = x.counter_;
+          return *this;
+        }
+
+        template <typename Z>
+        counter_ops&
+        operator= (const counter_ops<Z, Z>& x)
+        {
+          counter_ = x.counter_;
+          return *this;
+        }
+
+        void
+        reset (const X* p)
+        {
+          counter_ = p ? bits::counter (p) : 0;
+        }
+
+        void
+        inc (X*)
+        {
+          (*counter_)++;
+        }
+
+        void
+        dec (X* p)
+        {
+          if (--(*counter_) == 0)
+          {
+            p->~X ();
+
+            // Counter is the top of the memory block.
+            //
+            operator delete (counter_);
+          }
+        }
+
+        std::size_t
+        count (const X*) const
+        {
+          return *counter_;
+        }
+
+        std::size_t* counter_;
+      };
+
+      template <typename Y>
+      struct counter_ops<shared_base, Y>
+      {
+        counter_ops (const Y*) {}
+        counter_ops (const counter_ops&) {}
+
+        template <typename Z>
+        counter_ops (const counter_ops<shared_base, Z>&) {}
+
+        counter_ops&
+        operator= (const counter_ops&)
+        {
+          return *this;
+        }
+
+        template <typename Z>
+        counter_ops&
+        operator= (const counter_ops<shared_base, Z>&)
+        {
+          return *this;
+        }
+
+        void
+        reset (const Y*) {}
+
+        void
+        inc (shared_base* p) {p->_inc_ref ();}
+
+        void
+        dec (Y* p)
+        {
+          if (static_cast<shared_base*> (p)->_dec_ref ())
+            delete p;
+        }
+
+        std::size_t
+        count (const shared_base* p) const {return p->_ref_count ();}
+      };
+    }
+
+    template <typename X>
+    inline X*
+    inc_ref (X* p)
+    {
+      bits::counter_ops<typename bits::counter_type<X>::r, X> c (p);
+      c.inc (p);
+      return p;
+    }
+
+    template <typename X>
+    inline void
+    dec_ref (X* p)
+    {
+      bits::counter_ops<typename bits::counter_type<X>::r, X> c (p);
+      c.dec (p);
+    }
+
+    template <typename X>
+    inline std::size_t
+    ref_count (const X* p)
+    {
+      bits::counter_ops<typename bits::counter_type<X>::r, X> c (p);
+      return c.count (p);
+    }
+  }
+}
-- 
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