From boris at codesynthesis.com  Tue Jul  1 10:24:44 2025
From: boris at codesynthesis.com (Boris Kolpackov)
Date: Tue Jul  1 10:24:58 2025
Subject: [odb-users] Potential Bug in Bulk Persist template
	(libodb/odb/database.ixx)
In-Reply-To: <FR3P281MB22521D0C58C0B8A30316CF88FB45A@FR3P281MB2252.DEUP281.PROD.OUTLOOK.COM>
References: <FR3P281MB22521D0C58C0B8A30316CF88FB45A@FR3P281MB2252.DEUP281.PROD.OUTLOOK.COM>
Message-ID: <boris.20250701162356@codesynthesis.com>

See discussion in https://github.com/codesynthesis-com/odb/issues/15

From lloydkl.tech at gmail.com  Tue Jul 15 07:51:38 2025
From: lloydkl.tech at gmail.com (Lloyd)
Date: Tue Jul 15 08:01:39 2025
Subject: [odb-users] Operator delete overload - odb::sqlite::database
	destruction
Message-ID: <CAA10ZTrSbHqtvBGUx2uabpt-BuKLW=LZyS3yOVVNrM2o+_9gSA@mail.gmail.com>

To track the memory leaks (Windows 10, Visual Studio 2019, C++17), the
operator new, new[], delete, delete[] are overloaded in the application.
The overloaded new allocates extra memory and adds a header which contains
the tracking information.

When I execute the below code block the overloaded delete is called and the
program exits normally.

{
auto a = std::unique_ptr<int>(new int(2));
}

But, when I call the following code block, the default std::delete is
called (instead of the overloaded delete) which causes an exception to be
thrown (as the code returns; instead of the original allocation pointer, an
offset from the allocated pointer is returned) .

{
    std::unique_ptr<odb::sqlite::database> Connection;
    {
         Connection = std::unique_ptr<odb::sqlite::database>(new
odb::sqlite::database("C:\\temp\\test.db", SQLITE_OPEN_CREATE |
SQLITE_OPEN_READWRITE));
    }
}

The ODB 2.5.0 libraries are built using 'build2' as given in the
documentation (
https://www.codesynthesis.com/products/odb/doc/install-build2.xhtml#windows),
debug build (application and ODB),  /Od, /MDd, /Zi, Shared

Looks like this issue is caused by delete from the DLL. Could you please
shed some light on this?

Thanks and Regards,
From boris at codesynthesis.com  Wed Jul 16 10:41:21 2025
From: boris at codesynthesis.com (Boris Kolpackov)
Date: Wed Jul 16 10:41:35 2025
Subject: [odb-users] Operator delete overload - odb::sqlite::database
	destruction
In-Reply-To: <CAA10ZTrSbHqtvBGUx2uabpt-BuKLW=LZyS3yOVVNrM2o+_9gSA@mail.gmail.com>
References: <CAA10ZTrSbHqtvBGUx2uabpt-BuKLW=LZyS3yOVVNrM2o+_9gSA@mail.gmail.com>
Message-ID: <boris.20250716163955@codesynthesis.com>

Lloyd <lloydkl.tech@gmail.com> writes:

> Looks like this issue is caused by delete from the DLL.

Yes, that was my first hunch.


> Could you please shed some light on this?

Nope, I don't think you can make overloaded new/delete work across
DLLs on Windows.

From odb at a-cunningham.com  Tue Jul 22 17:41:05 2025
From: odb at a-cunningham.com (Andrew Cunningham)
Date: Tue Jul 22 17:41:42 2025
Subject: [odb-users] Operator delete overload - odb::sqlite::database
	destruction
In-Reply-To: <boris.20250716163955@codesynthesis.com>
References: <CAA10ZTrSbHqtvBGUx2uabpt-BuKLW=LZyS3yOVVNrM2o+_9gSA@mail.gmail.com>
	<boris.20250716163955@codesynthesis.com>
Message-ID: <CAGTJuHgg90r64osEaHBB2TGysXD03F0qAfULa0vuDA6oX4aYrA@mail.gmail.com>

As Boris points out , overriding the global new/delete is not possible
across DLL boundaries on Windows.
You can however override the standard malloc/free

https://microsoft.github.io/mimalloc/overrides.html

On Wed, Jul 16, 2025 at 7:41?AM Boris Kolpackov <boris@codesynthesis.com> wrote:
>
> Lloyd <lloydkl.tech@gmail.com> writes:
>
> > Looks like this issue is caused by delete from the DLL.
>
> Yes, that was my first hunch.
>
>
> > Could you please shed some light on this?
>
> Nope, I don't think you can make overloaded new/delete work across
> DLLs on Windows.
>