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// file : odb/details/shared-ptr/base.cxx
// copyright : Copyright (c) 2009-2015 Code Synthesis Tools CC
// license : GNU GPL v2; see accompanying LICENSE file
#include <odb/details/shared-ptr/base.hxx>
#include <odb/details/shared-ptr/exception.hxx>
using std::size_t;
namespace odb
{
namespace details
{
share shared = share (1);
share exclusive = share (2);
const char* not_shared::
what () const ODB_NOTHROW_NOEXCEPT
{
return "object is not shared";
}
not_shared* not_shared::
clone () const
{
return new not_shared (*this);
}
bool shared_base::
_dec_ref_callback ()
{
bool r (--counter_ == 0);
if (r)
r = callback_->zero_counter (callback_->arg);
return r;
}
namespace bits
{
size_t* locator_common::
counter (void* x)
{
size_t* p (static_cast<size_t*> (x));
if (*(--p) != 0xDEADBEEF)
throw not_shared ();
return --p;
}
}
}
}
void*
#ifdef ODB_CXX11
operator new (size_t n, odb::details::share s)
#else
operator new (size_t n, odb::details::share s) throw (std::bad_alloc)
#endif
{
if (s == odb::details::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, odb::details::share s) ODB_NOTHROW_NOEXCEPT
{
// 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 == odb::details::shared)
{
size_t* sp = static_cast<size_t*> (p);
sp -= 2;
operator delete (sp);
}
else
operator delete (p);
}
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