* Shared (garbage collecting) pointers. Copied from Boost.

1 files changed, 555 insertions, 0 deletions

diff --git a/src/boost/detail/shared_count.hpp b/src/boost/detail/shared_count.hpp
new file mode 100644
index 000000000000..23e78413f721
--- /dev/null
+++ b/src/boost/detail/shared_count.hpp
@@ -0,0 +1,555 @@
+#ifndef BOOST_DETAIL_SHARED_COUNT_HPP_INCLUDED
+#define BOOST_DETAIL_SHARED_COUNT_HPP_INCLUDED
+
+// MS compatible compilers support #pragma once
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+//
+//  detail/shared_count.hpp
+//
+//  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
+//
+//  Permission to copy, use, modify, sell and distribute this software
+//  is granted provided this copyright notice appears in all copies.
+//  This software is provided "as is" without express or implied
+//  warranty, and with no claim as to its suitability for any purpose.
+//
+
+//#include <boost/config.hpp>
+
+#if defined(BOOST_SP_USE_STD_ALLOCATOR) && defined(BOOST_SP_USE_QUICK_ALLOCATOR)
+# error BOOST_SP_USE_STD_ALLOCATOR and BOOST_SP_USE_QUICK_ALLOCATOR are incompatible.
+#endif
+
+#include <boost/checked_delete.hpp>
+#include <boost/throw_exception.hpp>
+//#include <boost/detail/lightweight_mutex.hpp>
+
+#if defined(BOOST_SP_USE_QUICK_ALLOCATOR)
+#include <boost/detail/quick_allocator.hpp>
+#endif
+
+#include <memory>           // std::auto_ptr, std::allocator
+#include <functional>       // std::less
+#include <exception>        // std::exception
+#include <new>              // std::bad_alloc
+#include <typeinfo>         // std::type_info in get_deleter
+#include <cstddef>          // std::size_t
+
+#ifdef __BORLANDC__
+# pragma warn -8026     // Functions with excep. spec. are not expanded inline
+# pragma warn -8027     // Functions containing try are not expanded inline
+#endif
+
+namespace boost
+{
+
+// Debug hooks
+
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+
+void sp_scalar_constructor_hook(void * px, std::size_t size, void * pn);
+void sp_array_constructor_hook(void * px);
+void sp_scalar_destructor_hook(void * px, std::size_t size, void * pn);
+void sp_array_destructor_hook(void * px);
+
+#endif
+
+
+// The standard library that comes with Borland C++ 5.5.1
+// defines std::exception and its members as having C calling
+// convention (-pc). When the definition of bad_weak_ptr
+// is compiled with -ps, the compiler issues an error.
+// Hence, the temporary #pragma option -pc below. The version
+// check is deliberately conservative.
+
+#if defined(__BORLANDC__) && __BORLANDC__ == 0x551
+# pragma option push -pc
+#endif
+
+class bad_weak_ptr: public std::exception
+{
+public:
+
+    virtual char const * what() const throw()
+    {
+        return "boost::bad_weak_ptr";
+    }
+};
+
+#if defined(__BORLANDC__) && __BORLANDC__ == 0x551
+# pragma option pop
+#endif
+
+namespace detail
+{
+
+class sp_counted_base
+{
+private:
+
+    //    typedef detail::lightweight_mutex mutex_type;
+
+public:
+
+    sp_counted_base(): use_count_(1), weak_count_(1)
+    {
+    }
+
+    virtual ~sp_counted_base() // nothrow
+    {
+    }
+
+    // dispose() is called when use_count_ drops to zero, to release
+    // the resources managed by *this.
+
+    virtual void dispose() = 0; // nothrow
+
+    // destruct() is called when weak_count_ drops to zero.
+
+    virtual void destruct() // nothrow
+    {
+        delete this;
+    }
+
+    virtual void * get_deleter(std::type_info const & ti) = 0;
+
+    void add_ref_copy()
+    {
+#if defined(BOOST_HAS_THREADS)
+        mutex_type::scoped_lock lock(mtx_);
+#endif
+        ++use_count_;
+    }
+
+    void add_ref_lock()
+    {
+#if defined(BOOST_HAS_THREADS)
+        mutex_type::scoped_lock lock(mtx_);
+#endif
+        if(use_count_ == 0) boost::throw_exception(boost::bad_weak_ptr());
+        ++use_count_;
+    }
+
+    void release() // nothrow
+    {
+        {
+#if defined(BOOST_HAS_THREADS)
+            mutex_type::scoped_lock lock(mtx_);
+#endif
+            long new_use_count = --use_count_;
+
+            if(new_use_count != 0) return;
+        }
+
+        dispose();
+        weak_release();
+    }
+
+    void weak_add_ref() // nothrow
+    {
+#if defined(BOOST_HAS_THREADS)
+        mutex_type::scoped_lock lock(mtx_);
+#endif
+        ++weak_count_;
+    }
+
+    void weak_release() // nothrow
+    {
+        long new_weak_count;
+
+        {
+#if defined(BOOST_HAS_THREADS)
+            mutex_type::scoped_lock lock(mtx_);
+#endif
+            new_weak_count = --weak_count_;
+        }
+
+        if(new_weak_count == 0)
+        {
+            destruct();
+        }
+    }
+
+    long use_count() const // nothrow
+    {
+#if defined(BOOST_HAS_THREADS)
+        mutex_type::scoped_lock lock(mtx_);
+#endif
+        return use_count_;
+    }
+
+private:
+
+    sp_counted_base(sp_counted_base const &);
+    sp_counted_base & operator= (sp_counted_base const &);
+
+    long use_count_;        // #shared
+    long weak_count_;       // #weak + (#shared != 0)
+
+#if defined(BOOST_HAS_THREADS) || defined(BOOST_LWM_WIN32)
+    mutable mutex_type mtx_;
+#endif
+};
+
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+
+template<class T> void cbi_call_constructor_hook(sp_counted_base * pn, T * px, checked_deleter<T> const &, int)
+{
+    boost::sp_scalar_constructor_hook(px, sizeof(T), pn);
+}
+
+template<class T> void cbi_call_constructor_hook(sp_counted_base *, T * px, checked_array_deleter<T> const &, int)
+{
+    boost::sp_array_constructor_hook(px);
+}
+
+template<class P, class D> void cbi_call_constructor_hook(sp_counted_base *, P const &, D const &, long)
+{
+}
+
+template<class T> void cbi_call_destructor_hook(sp_counted_base * pn, T * px, checked_deleter<T> const &, int)
+{
+    boost::sp_scalar_destructor_hook(px, sizeof(T), pn);
+}
+
+template<class T> void cbi_call_destructor_hook(sp_counted_base *, T * px, checked_array_deleter<T> const &, int)
+{
+    boost::sp_array_destructor_hook(px);
+}
+
+template<class P, class D> void cbi_call_destructor_hook(sp_counted_base *, P const &, D const &, long)
+{
+}
+
+#endif
+
+//
+// Borland's Codeguard trips up over the -Vx- option here:
+//
+#ifdef __CODEGUARD__
+# pragma option push -Vx-
+#endif
+
+template<class P, class D> class sp_counted_base_impl: public sp_counted_base
+{
+private:
+
+    P ptr; // copy constructor must not throw
+    D del; // copy constructor must not throw
+
+    sp_counted_base_impl(sp_counted_base_impl const &);
+    sp_counted_base_impl & operator= (sp_counted_base_impl const &);
+
+    typedef sp_counted_base_impl<P, D> this_type;
+
+public:
+
+    // pre: initial_use_count <= initial_weak_count, d(p) must not throw
+
+    sp_counted_base_impl(P p, D d): ptr(p), del(d)
+    {
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        detail::cbi_call_constructor_hook(this, p, d, 0);
+#endif
+    }
+
+    virtual void dispose() // nothrow
+    {
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        detail::cbi_call_destructor_hook(this, ptr, del, 0);
+#endif
+        del(ptr);
+    }
+
+    virtual void * get_deleter(std::type_info const & ti)
+    {
+        return ti == typeid(D)? &del: 0;
+    }
+
+#if defined(BOOST_SP_USE_STD_ALLOCATOR)
+
+    void * operator new(std::size_t)
+    {
+        return std::allocator<this_type>().allocate(1, static_cast<this_type *>(0));
+    }
+
+    void operator delete(void * p)
+    {
+        std::allocator<this_type>().deallocate(static_cast<this_type *>(p), 1);
+    }
+
+#endif
+
+#if defined(BOOST_SP_USE_QUICK_ALLOCATOR)
+
+    void * operator new(std::size_t)
+    {
+        return quick_allocator<this_type>::alloc();
+    }
+
+    void operator delete(void * p)
+    {
+        quick_allocator<this_type>::dealloc(p);
+    }
+
+#endif
+};
+
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+
+int const shared_count_id = 0x2C35F101;
+int const   weak_count_id = 0x298C38A4;
+
+#endif
+
+class weak_count;
+
+class shared_count
+{
+private:
+
+    sp_counted_base * pi_;
+
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+    int id_;
+#endif
+
+    friend class weak_count;
+
+public:
+
+    shared_count(): pi_(0) // nothrow
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        , id_(shared_count_id)
+#endif
+    {
+    }
+
+    template<class P, class D> shared_count(P p, D d): pi_(0)
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        , id_(shared_count_id)
+#endif
+    {
+#ifndef BOOST_NO_EXCEPTIONS
+
+        try
+        {
+            pi_ = new sp_counted_base_impl<P, D>(p, d);
+        }
+        catch(...)
+        {
+            d(p); // delete p
+            throw;
+        }
+
+#else
+
+        pi_ = new sp_counted_base_impl<P, D>(p, d);
+
+        if(pi_ == 0)
+        {
+            d(p); // delete p
+            boost::throw_exception(std::bad_alloc());
+        }
+
+#endif
+    }
+
+#ifndef BOOST_NO_AUTO_PTR
+
+    // auto_ptr<Y> is special cased to provide the strong guarantee
+
+    template<class Y>
+    explicit shared_count(std::auto_ptr<Y> & r): pi_(new sp_counted_base_impl< Y *, checked_deleter<Y> >(r.get(), checked_deleter<Y>()))
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        , id_(shared_count_id)
+#endif
+    {
+        r.release();
+    }
+
+#endif 
+
+    ~shared_count() // nothrow
+    {
+        if(pi_ != 0) pi_->release();
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        id_ = 0;
+#endif
+    }
+
+    shared_count(shared_count const & r): pi_(r.pi_) // nothrow
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        , id_(shared_count_id)
+#endif
+    {
+        if(pi_ != 0) pi_->add_ref_copy();
+    }
+
+    explicit shared_count(weak_count const & r); // throws bad_weak_ptr when r.use_count() == 0
+
+    shared_count & operator= (shared_count const & r) // nothrow
+    {
+        sp_counted_base * tmp = r.pi_;
+        if(tmp != 0) tmp->add_ref_copy();
+        if(pi_ != 0) pi_->release();
+        pi_ = tmp;
+
+        return *this;
+    }
+
+    void swap(shared_count & r) // nothrow
+    {
+        sp_counted_base * tmp = r.pi_;
+        r.pi_ = pi_;
+        pi_ = tmp;
+    }
+
+    long use_count() const // nothrow
+    {
+        return pi_ != 0? pi_->use_count(): 0;
+    }
+
+    bool unique() const // nothrow
+    {
+        return use_count() == 1;
+    }
+
+    friend inline bool operator==(shared_count const & a, shared_count const & b)
+    {
+        return a.pi_ == b.pi_;
+    }
+
+    friend inline bool operator<(shared_count const & a, shared_count const & b)
+    {
+        return std::less<sp_counted_base *>()(a.pi_, b.pi_);
+    }
+
+    void * get_deleter(std::type_info const & ti) const
+    {
+        return pi_? pi_->get_deleter(ti): 0;
+    }
+};
+
+#ifdef __CODEGUARD__
+# pragma option pop
+#endif
+
+
+class weak_count
+{
+private:
+
+    sp_counted_base * pi_;
+
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+    int id_;
+#endif
+
+    friend class shared_count;
+
+public:
+
+    weak_count(): pi_(0) // nothrow
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        , id_(weak_count_id)
+#endif
+    {
+    }
+
+    weak_count(shared_count const & r): pi_(r.pi_) // nothrow
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        , id_(shared_count_id)
+#endif
+    {
+        if(pi_ != 0) pi_->weak_add_ref();
+    }
+
+    weak_count(weak_count const & r): pi_(r.pi_) // nothrow
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        , id_(shared_count_id)
+#endif
+    {
+        if(pi_ != 0) pi_->weak_add_ref();
+    }
+
+    ~weak_count() // nothrow
+    {
+        if(pi_ != 0) pi_->weak_release();
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        id_ = 0;
+#endif
+    }
+
+    weak_count & operator= (shared_count const & r) // nothrow
+    {
+        sp_counted_base * tmp = r.pi_;
+        if(tmp != 0) tmp->weak_add_ref();
+        if(pi_ != 0) pi_->weak_release();
+        pi_ = tmp;
+
+        return *this;
+    }
+
+    weak_count & operator= (weak_count const & r) // nothrow
+    {
+        sp_counted_base * tmp = r.pi_;
+        if(tmp != 0) tmp->weak_add_ref();
+        if(pi_ != 0) pi_->weak_release();
+        pi_ = tmp;
+
+        return *this;
+    }
+
+    void swap(weak_count & r) // nothrow
+    {
+        sp_counted_base * tmp = r.pi_;
+        r.pi_ = pi_;
+        pi_ = tmp;
+    }
+
+    long use_count() const // nothrow
+    {
+        return pi_ != 0? pi_->use_count(): 0;
+    }
+
+    friend inline bool operator==(weak_count const & a, weak_count const & b)
+    {
+        return a.pi_ == b.pi_;
+    }
+
+    friend inline bool operator<(weak_count const & a, weak_count const & b)
+    {
+        return std::less<sp_counted_base *>()(a.pi_, b.pi_);
+    }
+};
+
+inline shared_count::shared_count(weak_count const & r): pi_(r.pi_)
+#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
+        , id_(shared_count_id)
+#endif
+{
+    if(pi_ != 0)
+    {
+        pi_->add_ref_lock();
+    }
+    else
+    {
+        boost::throw_exception(boost::bad_weak_ptr());
+    }
+}
+
+} // namespace detail
+
+} // namespace boost
+
+#ifdef __BORLANDC__
+# pragma warn .8027     // Functions containing try are not expanded inline
+# pragma warn .8026     // Functions with excep. spec. are not expanded inline
+#endif
+
+#endif  // #ifndef BOOST_DETAIL_SHARED_COUNT_HPP_INCLUDED