From cb9ea47e7825b5073d4d645afb94f6326cb7cf4d Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Sun, 6 Sep 2009 12:52:53 +0200 Subject: Start the libcutl repository --- cutl/shared-ptr/base.cxx | 63 +++++++++++++++++ cutl/shared-ptr/base.hxx | 90 ++++++++++++++++++++++++ cutl/shared-ptr/base.ixx | 79 +++++++++++++++++++++ cutl/shared-ptr/base.txx | 174 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 406 insertions(+) create mode 100644 cutl/shared-ptr/base.cxx create mode 100644 cutl/shared-ptr/base.hxx create mode 100644 cutl/shared-ptr/base.ixx create mode 100644 cutl/shared-ptr/base.txx (limited to 'cutl/shared-ptr') 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 +// copyright : Copyright (c) 2009 Code Synthesis Tools CC +// license : MIT; see accompanying LICENSE file + +#include + +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 (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 (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 +// 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 +#include // std::size_t +#include // 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 + inline X* + inc_ref (X*); + + template + inline void + dec_ref (X*); + + template + inline std::size_t + ref_count (X const*); +} + +#include +#include + +#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 +// 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 +// copyright : Copyright (c) 2009 Code Synthesis Tools CC +// license : MIT; see accompanying LICENSE file + +#include +#include + +namespace cutl +{ + namespace bits + { + // Support for locating the counter in the memory block. + // + template ::r> + struct locator; + + template + struct locator + { + static std::size_t* + counter (X* x) + { + std::size_t* p (reinterpret_cast (x)); + + if (*(--p) != 0xDEADBEEF) + throw not_shared (); + + return --p; + } + }; + + template + struct locator + { + static std::size_t* + counter (X* x) + { + std::size_t* p ( + static_cast ( + dynamic_cast (x))); + + if (*(--p) != 0xDEADBEEF) + throw not_shared (); + + return --p; + } + }; + + template + std::size_t* + counter (X const* p) + { + return bits::locator::counter (const_cast (p)); + } + + // Counter type and operations. + // + meta::no test (...); + meta::yes test (shared_base*); + + template (0)))> + struct counter_type; + + template + struct counter_type + { + typedef X r; + }; + + template + struct counter_type + { + typedef shared_base r; + }; + + template + struct counter_ops; + + template + struct counter_ops + { + counter_ops (X const* p) : counter_ (p ? bits::counter (p) : 0) {} + counter_ops (counter_ops const& x) : counter_ (x.counter_) {} + + template + counter_ops (counter_ops const& x) : counter_ (x.counter_) {} + + counter_ops& + operator= (counter_ops const& x) + { + counter_ = x.counter_; + return *this; + } + + template + counter_ops& + operator= (counter_ops 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 + struct counter_ops + { + counter_ops (Y const*) {} + + void + inc (shared_base* p) {p->_inc_ref ();} + + void + dec (Y* p) + { + if (static_cast (p)->_dec_ref ()) + delete p; + } + + std::size_t + count (shared_base const* p) const {return p->_ref_count ();} + }; + } + + template + inline X* + inc_ref (X* p) + { + bits::counter_ops::r, X> c (p); + c.inc (p); + return p; + } + + template + inline void + dec_ref (X* p) + { + bits::counter_ops::r, X> c (p); + c.dec (p); + } + + template + inline std::size_t + ref_count (X const* p) + { + bits::counter_ops::r, X> c (p); + return c.count (p); + } +} -- cgit v1.1