The same Python DLL loaded twice

[Mateusz Loskot]

Hi,

I'm experiencing strange issue with the very same python32.dll being
loaded twice on Windows.

I have an application which embeds Python.
Launching my app loads python32.dll for the first time and all seems
working well.
Next, under the embedded Python, I execute this one-liner
"import tkinter"

This triggers loading of _tkinter.pyd, tk85.dll, tcl85.dll as well as
python32.dll for the second time.

The duplicate python32.dll is loaded into different address space,
maintains its own thread state,
leading to crash from PyInit__tkinter, obviously.

The problem seems to be similar to this one
http://stackoverflow.com/questions/2147729/dll-file-loaded-twice-with-dll-redirection-through-manifest/

Has anyone experience similar issues?
Any ideas on possible reasons of duplicate loading of python32.dll?

Best regards,

[M.-A. Lemburg]

Post by Mateusz Loskot
Hi,
I'm experiencing strange issue with the very same python32.dll being
loaded twice on Windows.
I have an application which embeds Python.
Launching my app loads python32.dll for the first time and all seems
working well.
Next, under the embedded Python, I execute this one-liner
"import tkinter"
This triggers loading of _tkinter.pyd, tk85.dll, tcl85.dll as well as
python32.dll for the second time.
The duplicate python32.dll is loaded into different address space,
maintains its own thread state,
leading to crash from PyInit__tkinter, obviously.
The problem seems to be similar to this one
http://stackoverflow.com/questions/2147729/dll-file-loaded-twice-with-dll-redirection-through-manifest/
Has anyone experience similar issues?
Any ideas on possible reasons of duplicate loading of python32.dll?

Could you check the version numbers of those two DLLs.

It's possible that you're loading a Python DLL for say 3.2.1
and one for 3.2.2.
--
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Source (#1, Oct 07 2013)

Post by Mateusz Loskot

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[Mateusz Loskot]

Post by M.-A. Lemburg

Post by Mateusz Loskot
Hi,
I'm experiencing strange issue with the very same python32.dll being
loaded twice on Windows.
I have an application which embeds Python.
Launching my app loads python32.dll for the first time and all seems
working well.
Next, under the embedded Python, I execute this one-liner
"import tkinter"
This triggers loading of _tkinter.pyd, tk85.dll, tcl85.dll as well as
python32.dll for the second time.
The duplicate python32.dll is loaded into different address space,
maintains its own thread state,
leading to crash from PyInit__tkinter, obviously.
The problem seems to be similar to this one
http://stackoverflow.com/questions/2147729/dll-file-loaded-twice-with-dll-redirection-through-manifest/
Has anyone experience similar issues?
Any ideas on possible reasons of duplicate loading of python32.dll?

Could you check the version numbers of those two DLLs.
It's possible that you're loading a Python DLL for say 3.2.1
and one for 3.2.2.

Yes, I have checked that file name, file path and version of the Python DLL
which is loaded twice are all the same.
The two loadings refer to the very same file.

I eventually found where is the problem.
The application which embeds Python is linked with Python DLL
and it refers to Python assembly using custom manifest specified wit

#pragma comment(linker, "\"/manifestdependency:name='Python' ... )

But, _tkinter.pyd does not load Python through the manifest.
So, the application and the _tkinter.pyd link to Python DLL
as they would be two distinct assemblies.

If I remove the /manifestdependency directive from my application, rebuild it
and ensure Python DLL is present in DLL search path,
then no double loading occurs and all works well.

The side-by-side technology is a bit slippery :)

Best regards,