Re: [Boost-users] [shared_ptr] make_shared causes Access Violation

Subject: Re: [Boost-users] [shared_ptr] make_shared causes Access Violation
From: Krzysztof Czainski (1czajnik_at_[hidden])
Date: 2011-05-10 16:17:04

2011/5/10 Paul Heil <paul.heil_at_[hidden]>

> I have a Visual Studio 2008 C++ application for ARMV4I Windows Mobile 6
> where I'm using `boost::shared_ptr<>` to manage a fairly large object (4KB).
> Unfortunately, `boost::make_shared<>` causes an Access Violation exception.
> I am using Boost 1.45.0 with STLPort 5.2.1.
>
> My code:
>
>     struct Foo
>     {
>         char a[ 4 * 1024 - 1 ];
>     };
>
>     int _tmain( int argc, _TCHAR* argv[] )
>     {
>         boost::shared_ptr< Foo > f = boost::make_shared< Foo >(); // Access
> Violation
>         return 0;
>     }
>
> The exception callstack:
>
>     test.exe!boost::detail::sp_ms_deleter<o>::sp_ms_deleter<o>(void) Line:
> 60, Byte Offsets: 0x18    C++
>     test.exe!boost::make_shared<o>(void) Line: 106, Byte Offsets: 0x5c
> C++
>     test.exe!wmain(int argc = 1, wchar_t** argv = 0x01b40060) Line: 81,
> Byte Offsets: 0x18    C++
>     test.exe!mainWCRTStartup(HINSTANCE__* hInstance = 0x00000003,
> HINSTANCE__* hInstancePrev = 0x00000000, unsigned short* lpszCmdLine =
> 0x00000003, int nCmdShow = 0) Line: 188, Byte Offsets: 0x94    C++
>
> The location of the exception (boost\smart_ptr\make_shared.hpp):
>
>     template< class T > class sp_ms_deleter
>     {
>         /* snip! */
>     public:
>         sp_ms_deleter(): initialized_( false )
>         {    // line: 60  this = NULL
>         }
>
>         /* snip! */
>
> This issue does not occur when compiling for x86 Windows. This issue also
> does not occur when using the shared_ptr like this:
>
>     boost::shared_ptr< Foo > f1 = boost::shared_ptr< Foo >( new Foo );
>
> Can anybody explain what's going on and why this is breaking only on ARMV4I
> Windows Mobile 6?
>
> Thanks,
> PaulH
>

My guess: stack overflow. If I remember correctly, 2 times sizeof( Foo )
must fit on the stack when using make_shared.

Regards,
Kris