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-rw-r--r--cutl/shared-ptr/base.cxx63
-rw-r--r--cutl/shared-ptr/base.hxx90
-rw-r--r--cutl/shared-ptr/base.ixx79
-rw-r--r--cutl/shared-ptr/base.txx174
4 files changed, 406 insertions, 0 deletions
diff --git a/cutl/shared-ptr/base.cxx b/cutl/shared-ptr/base.cxx
new file mode 100644
index 0000000..a74ed15
--- /dev/null
+++ b/cutl/shared-ptr/base.cxx
@@ -0,0 +1,63 @@
+// file : cutl/shared-ptr/base.cxx
+// author : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009 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/cutl/shared-ptr/base.hxx b/cutl/shared-ptr/base.hxx
new file mode 100644
index 0000000..bb297cb
--- /dev/null
+++ b/cutl/shared-ptr/base.hxx
@@ -0,0 +1,90 @@
+// file : cutl/shared-ptr/base.hxx
+// author : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009 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 <exception> // std::exception
+
+namespace cutl
+{
+ struct share
+ {
+ explicit
+ share (char id);
+
+ bool
+ operator== (share) const;
+
+ private:
+ char id_;
+ };
+}
+
+extern cutl::share shared;
+extern cutl::share exclusive;
+
+void*
+operator new (std::size_t, cutl::share) throw (std::bad_alloc);
+
+void
+operator delete (void*, cutl::share) throw ();
+
+namespace cutl
+{
+ struct not_shared: std::exception
+ {
+ virtual char const*
+ what () const throw ();
+ };
+
+ struct 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/cutl/shared-ptr/base.ixx b/cutl/shared-ptr/base.ixx
new file mode 100644
index 0000000..928e439
--- /dev/null
+++ b/cutl/shared-ptr/base.ixx
@@ -0,0 +1,79 @@
+// file : cutl/shared-ptr/base.ixx
+// author : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009 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/cutl/shared-ptr/base.txx b/cutl/shared-ptr/base.txx
new file mode 100644
index 0000000..168fb52
--- /dev/null
+++ b/cutl/shared-ptr/base.txx
@@ -0,0 +1,174 @@
+// file : cutl/shared-ptr/base.txx
+// author : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : Copyright (c) 2009 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 (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 Y>
+ counter_ops (counter_ops<Y, Y> const& x) : counter_ (x.counter_) {}
+
+ counter_ops&
+ operator= (counter_ops const& x)
+ {
+ counter_ = x.counter_;
+ return *this;
+ }
+
+ template <typename Y>
+ counter_ops&
+ operator= (counter_ops<Y, Y> const& x)
+ {
+ counter_ = x.counter_;
+ return *this;
+ }
+
+ 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*) {}
+
+ 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);
+ }
+}
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