I am using boost share_ptr and I have a very strange problem. it looks
to me more like a compiler problem but since it is a boost code I
decided to post it here. I haven't succeeded to creating a small example
which I can post here and demonstrate the problem (I know it is hard to
help that way but I am working on creating an example) so I will just
describe it.
The symptom is that the shared_ptr call the delete on a random pointer.
Going into the shared_ptr and shared_count objects, I sow that the ptr
field of sp_counted_base_impl has a wrong value. I have added prints
out all over the code and saw that inside the constructor of
sp_counted_base_impl the value is set correctly but on the return when I
try to look at the value and it is a wrong value. adding some more
prints I saw that inside the shared_count constructor: template shared_count(P p, D d)
when casting pi_ to (sp_counted_base_impl*) and calling a member
function, the sizeof(*this) in side the member function is not the same
every time (resulting with a different address to ptr and thus different
value).
the problem occurs only when compiling -O
I am attaching the two file I have changes (shared_count.hpp is from
boost/detail/) and the prints there created.
I am sorry I can't supplied a complete example, this problems can just
disappear when I remove any object file from the compilation.
my configuration:
compiler: gcc version 3.2 20020903 (Red Hat Linux 8.0 3.2-7)
OS: Red Hat Linux release 8.0 (Psyche)
boost: boost-1.30.2
any help will be appreciated
#ifndef BOOST_SHARED_PTR_HPP_INCLUDED
#define BOOST_SHARED_PTR_HPP_INCLUDED
//
// shared_ptr.hpp
//
// (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
// Copyright (c) 2001, 2002, 2003 Peter Dimov
//
// 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.
//
// See http://www.boost.org/libs/smart_ptr/shared_ptr.htm for documentation.
//
#include // for broken compiler workarounds
#if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
#include
#else
#include
#include
#include
#include
#include
#include <memory> // for std::auto_ptr
#include <algorithm> // for std::swap
#include <functional> // for std::less
#include <typeinfo> // for std::bad_cast
#include <iosfwd> // for std::basic_ostream
#ifdef BOOST_MSVC // moved here to work around VC++ compiler crash
# pragma warning(push)
# pragma warning(disable:4284) // odd return type for operator->
#endif
namespace boost
{
template<class T> class weak_ptr;
template<class T> class enable_shared_from_this;
namespace detail
{
struct static_cast_tag {};
struct dynamic_cast_tag {};
struct polymorphic_cast_tag {};
template<class T> struct shared_ptr_traits
{
typedef T & reference;
};
template<> struct shared_ptr_traits<void>
{
typedef void reference;
};
#if !defined(BOOST_NO_CV_VOID_SPECIALIZATIONS)
template<> struct shared_ptr_traits<void const>
{
typedef void reference;
};
#endif
// enable_shared_from_this support
template void sp_enable_shared_from_this(boost::enable_shared_from_this<T> * pe, Y * px, shared_count const & pn)
{
if(pe != 0) pe->_internal_weak_this._internal_assign(px, pn);
}
inline void sp_enable_shared_from_this(void const *, void const *, shared_count const &)
{
}
} // namespace detail
//
// shared_ptr
//
// An enhanced relative of scoped_ptr with reference counted copy semantics.
// The object pointed to is deleted when the last shared_ptr pointing to it
// is destroyed or reset.
//
template<class T> class shared_ptr
{
private:
// Borland 5.5.1 specific workaround
typedef shared_ptr<T> this_type;
public:
typedef T element_type;
typedef T value_type;
typedef T * pointer;
typedef typename detail::shared_ptr_traits<T>::reference reference;
shared_ptr(): px(0), pn() // never throws in 1.30+
{
}
template<class Y>
explicit shared_ptr(Y * p): px(p), pn(p, checked_deleter<Y>()) // Y must be complete
// Eyal Fink changed that!!!
//shared_ptr(Y * p): px(p), pn(p, checked_deleter<Y>()) // Y must be complete
{
print_ptrs();
detail::sp_enable_shared_from_this(p, p, pn);
print_ptrs();
}
void print_ptrs()
{
//cout <<"px= "< inline bool operator==(shared_ptr<T> const & a, shared_ptr<U> const & b)
{
return a.get() == b.get();
}
template inline bool operator!=(shared_ptr<T> const & a, shared_ptr<U> const & b)
{
return a.get() != b.get();
}
#if __GNUC__ == 2 && __GNUC_MINOR__ <= 96
// Resolve the ambiguity between our op!= and the one in rel_ops
template<class T> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<T> const & b)
{
return a.get() != b.get();
}
#endif
template inline bool operator<(shared_ptr<T> const & a, shared_ptr<U> const & b)
{
return a._internal_less(b);
}
template<class T> inline void swap(shared_ptr<T> & a, shared_ptr<T> & b)
{
a.swap(b);
}
template shared_ptr<T> static_pointer_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, detail::static_cast_tag());
}
template shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, detail::dynamic_cast_tag());
}
// shared_*_cast names are deprecated. Use *_pointer_cast instead.
template shared_ptr<T> shared_static_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, detail::static_cast_tag());
}
template shared_ptr<T> shared_dynamic_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, detail::dynamic_cast_tag());
}
template shared_ptr<T> shared_polymorphic_cast(shared_ptr<U> const & r)
{
return shared_ptr<T>(r, detail::polymorphic_cast_tag());
}
template shared_ptr<T> shared_polymorphic_downcast(shared_ptr<U> const & r)
{
BOOST_ASSERT(dynamic_cast(r.get()) == r.get());
return shared_static_cast<T>(r);
}
// get_pointer() enables boost::mem_fn to recognize shared_ptr
template<class T> inline T * get_pointer(shared_ptr<T> const & p)
{
return p.get();
}
// operator<<
#if defined(__GNUC__) && (__GNUC__ < 3)
template<class Y> std::ostream & operator<< (std::ostream & os, shared_ptr<Y> const & p)
{
os << p.get();
return os;
}
#else
# if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, <= 1200 && __SGI_STL_PORT)
// MSVC6 has problems finding std::basic_ostream through the using declaration in namespace _STL
using std::basic_ostream;
template basic_ostream & operator<< (basic_ostream & os, shared_ptr<Y> const & p)
# else
template std::basic_ostream & operator<< (std::basic_ostream & os, shared_ptr<Y> const & p)
# endif
{
os << p.get();
return os;
}
#endif
// get_deleter (experimental)
#if defined(__GNUC__) && (__GNUC__ < 3)
// g++ 2.9x doesn't allow static_cast(void *)
template D * get_deleter(shared_ptr<T> const & p)
{
void const * q = p._internal_get_deleter(typeid(D));
return const_cast(static_cast(q));
}
#else
template D * get_deleter(shared_ptr<T> const & p)
{
return static_cast(p._internal_get_deleter(typeid(D)));
}
#endif
} // namespace boost
#ifdef BOOST_MSVC
# pragma warning(pop)
#endif
#endif // #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
#endif // #ifndef BOOST_SHARED_PTR_HPP_INCLUDED
#ifndef BOOST_DETAIL_SHARED_COUNT_HPP_INCLUDED
#define BOOST_DETAIL_SHARED_COUNT_HPP_INCLUDED
#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
#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
#include
#include
#if defined(BOOST_SP_USE_QUICK_ALLOCATOR)
#include
#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
{
}
virtual void *get_ptr()
{
exit(-1);
}
virtual void set_ptr(void *ptr)
{
//cout <<"we are not supposed to be here!"< 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 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 sp_counted_base_impl: public sp_counted_base
{
private:
D del; // copy constructor must not throw
P ptr; // 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 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)
{
cout <<"IN sp_counted_base_impl ocnstructro ptr="<().allocate(1, static_cast(0));
}
void operator delete(void * p)
{
std::allocator().deallocate(static_cast(p), 1);
}
#endif
#if defined(BOOST_SP_USE_QUICK_ALLOCATOR)
void * operator new(std::size_t)
{
return quick_allocator::alloc();
}
void operator delete(void * p)
{
quick_allocator::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 shared_count(P p, D d): pi_(0)
#if defined(BOOST_SP_ENABLE_DEBUG_HOOKS)
, id_(shared_count_id)
#endif
{
cout <<"in shared_count: p= "<(p, d);
cout <<"return from new sp_counted_base_impl1: p= "<ptr= "<get_ptr()<(p, d);
cout <<"return from new sp_counted_base_impl2: p= "<ptr= "<get_ptr()<*)pi_)->set_ptr(p);
cout <<"after fix: pi_->ptr= "
<<((sp_counted_base_impl*)pi_)->get_ptr()<
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