4 files changed, 431 insertions, 0 deletions
diff --git a/libcutl/cutl/shared-ptr/base.cxx b/libcutl/cutl/shared-ptr/base.cxx
new file mode 100644
index 0000000..1ff8469
--- /dev/null
+++ b/libcutl/cutl/shared-ptr/base.cxx
@@ -0,0 +1,62 @@
+// file      : cutl/shared-ptr/base.cxx
+// copyright : Copyright (c) 2009-2013 Code Synthesis Tools CC
+// license   : MIT; see accompanying LICENSE file
+
+#include <cutl/shared-ptr/base.hxx>
+
+using std::size_t;
+
+//
+//
+cutl::share shared = cutl::share (1);
+cutl::share exclusive = cutl::share (2);
+
+//
+//
+namespace cutl
+{
+  char const* not_shared::
+  what () const throw ()
+  {
+    return "object is not shared";
+  }
+}
+
+//
+//
+void*
+operator new (size_t n, cutl::share s) throw (std::bad_alloc)
+{
+  if (s == shared)
+  {
+    // Here we need to make sure we don't break the alignment of the
+    // returned block. For that we need to know the maximum alignment
+    // of this platform. Twice the pointer size is a good guess for
+    // most platforms.
+    //
+    size_t* p = static_cast<size_t*> (operator new (n + 2 * sizeof (size_t)));
+    *p++ = 1;          // Initial count.
+    *p++ = 0xDEADBEEF; // Signature.
+    return p;
+  }
+  else
+    return operator new (n);
+
+}
+
+void
+operator delete (void* p, cutl::share s) throw ()
+{
+  // This version of operator delete is only called when the c-tor
+  // fails. In this case there is no object and we can just free the
+  // memory.
+  //
+  if (s == shared)
+  {
+    size_t* sp = static_cast<size_t*> (p);
+    sp -= 2;
+    operator delete (sp);
+  }
+  else
+    operator delete (p);
+}
diff --git a/libcutl/cutl/shared-ptr/base.hxx b/libcutl/cutl/shared-ptr/base.hxx
new file mode 100644
index 0000000..f2bfecc
--- /dev/null
+++ b/libcutl/cutl/shared-ptr/base.hxx
@@ -0,0 +1,92 @@
+// file      : cutl/shared-ptr/base.hxx
+// copyright : Copyright (c) 2009-2013 Code Synthesis Tools CC
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef CUTL_SHARED_PTR_BASE_HXX
+#define CUTL_SHARED_PTR_BASE_HXX
+
+#include <new>
+#include <cstddef>   // std::size_t
+
+#include <cutl/exception.hxx>
+
+#include <cutl/details/export.hxx>
+
+namespace cutl
+{
+  struct LIBCUTL_EXPORT share
+  {
+    explicit
+    share (char id);
+
+    bool
+    operator== (share) const;
+
+  private:
+    char id_;
+  };
+}
+
+extern LIBCUTL_EXPORT cutl::share shared;
+extern LIBCUTL_EXPORT cutl::share exclusive;
+
+LIBCUTL_EXPORT void*
+operator new (std::size_t, cutl::share) throw (std::bad_alloc);
+
+LIBCUTL_EXPORT void
+operator delete (void*, cutl::share) throw ();
+
+namespace cutl
+{
+  struct LIBCUTL_EXPORT not_shared: exception
+  {
+    virtual char const*
+    what () const throw ();
+  };
+
+  struct LIBCUTL_EXPORT shared_base
+  {
+    shared_base ();
+    shared_base (shared_base const&);
+    shared_base&
+    operator= (shared_base const&);
+
+    void
+    _inc_ref ();
+
+    bool
+    _dec_ref ();
+
+    std::size_t
+    _ref_count () const;
+
+    void*
+    operator new (std::size_t, share) throw (std::bad_alloc);
+
+    void
+    operator delete (void*, share) throw ();
+
+    void
+    operator delete (void*) throw ();
+
+  protected:
+    std::size_t counter_;
+  };
+
+  template <typename X>
+  inline X*
+  inc_ref (X*);
+
+  template <typename X>
+  inline void
+  dec_ref (X*);
+
+  template <typename X>
+  inline std::size_t
+  ref_count (X const*);
+}
+
+#include <cutl/shared-ptr/base.ixx>
+#include <cutl/shared-ptr/base.txx>
+
+#endif // CUTL_SHARED_PTR_BASE_HXX
diff --git a/libcutl/cutl/shared-ptr/base.ixx b/libcutl/cutl/shared-ptr/base.ixx
new file mode 100644
index 0000000..14dd0ac
--- /dev/null
+++ b/libcutl/cutl/shared-ptr/base.ixx
@@ -0,0 +1,78 @@
+// file      : cutl/shared-ptr/base.ixx
+// copyright : Copyright (c) 2009-2013 Code Synthesis Tools CC
+// license   : MIT; see accompanying LICENSE file
+
+namespace cutl
+{
+  // share
+  //
+
+  inline share::
+  share (char id)
+      : id_ (id)
+  {
+  }
+
+  inline bool share::
+  operator== (share x) const
+  {
+    return id_ == x.id_;
+  }
+
+  // shared_base
+  //
+
+  inline shared_base::
+  shared_base ()
+      : counter_ (1)
+  {
+  }
+
+  inline shared_base::
+  shared_base (shared_base const&)
+      : counter_ (1)
+  {
+  }
+
+  inline shared_base& shared_base::
+  operator= (shared_base const&)
+  {
+    return *this;
+  }
+
+  inline void shared_base::
+  _inc_ref ()
+  {
+    counter_++;
+  }
+
+  inline bool shared_base::
+  _dec_ref ()
+  {
+    return --counter_ == 0;
+  }
+
+  inline std::size_t shared_base::
+  _ref_count () const
+  {
+    return counter_;
+  }
+
+  inline void* shared_base::
+  operator new (std::size_t n, share) throw (std::bad_alloc)
+  {
+    return ::operator new (n);
+  }
+
+  inline void shared_base::
+  operator delete (void* p, share) throw ()
+  {
+    ::operator delete (p);
+  }
+
+  inline void shared_base::
+  operator delete (void* p) throw ()
+  {
+    ::operator delete (p);
+  }
+}
diff --git a/libcutl/cutl/shared-ptr/base.txx b/libcutl/cutl/shared-ptr/base.txx
new file mode 100644
index 0000000..5096284
--- /dev/null
+++ b/libcutl/cutl/shared-ptr/base.txx
@@ -0,0 +1,199 @@
+// file      : cutl/shared-ptr/base.txx
+// copyright : Copyright (c) 2009-2013 Code Synthesis Tools CC
+// license   : MIT; see accompanying LICENSE file
+
+#include <cutl/meta/answer.hxx>
+#include <cutl/meta/polymorphic-p.hxx>
+
+namespace cutl
+{
+  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 (X const* 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 (X const* p) : counter_ (p ? bits::counter (p) : 0) {}
+      counter_ops (counter_ops const& x) : counter_ (x.counter_) {}
+
+      template <typename Z>
+      counter_ops (counter_ops<Z, Z> const& x) : counter_ (x.counter_) {}
+
+      counter_ops&
+      operator= (counter_ops const& x)
+      {
+        counter_ = x.counter_;
+        return *this;
+      }
+
+      template <typename Z>
+      counter_ops&
+      operator= (counter_ops<Z, Z> const& x)
+      {
+        counter_ = x.counter_;
+        return *this;
+      }
+
+      void
+      reset (X const* p)
+      {
+        counter_ = p ? bits::counter (p) : 0;
+      }
+
+      void
+      inc (X*)
+      {
+        (*counter_)++;
+      }
+
+      void
+      dec (X* p)
+      {
+        if (--(*counter_) == 0)
+        {
+          p->~X ();
+          operator delete (counter_); // Counter is the top of the memory block.
+        }
+      }
+
+      std::size_t
+      count (X const*) const
+      {
+        return *counter_;
+      }
+
+      std::size_t* counter_;
+    };
+
+    template <typename Y>
+    struct counter_ops<shared_base, Y>
+    {
+      counter_ops (Y const*) {}
+      counter_ops (counter_ops const&) {}
+
+      template <typename Z>
+      counter_ops (counter_ops<shared_base, Z> const&) {}
+
+      counter_ops&
+      operator= (counter_ops const&)
+      {
+        return *this;
+      }
+
+      template <typename Z>
+      counter_ops&
+      operator= (counter_ops<shared_base, Z> const&)
+      {
+        return *this;
+      }
+
+      void
+      reset (Y const*) {}
+
+      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 (shared_base const* 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 (X const* p)
+  {
+    bits::counter_ops<typename bits::counter_type<X>::r, X> c (p);
+    return c.count (p);
+  }
+}