[ python-Bugs-1144263 ] reload() is broken for C extension objects

[SourceForge.net]

Bugs item #1144263, was opened at 2005-02-19 04:20
Message generated for change (Comment added) made by knepley
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1144263&group_id=5470

Category: Python Interpreter Core
Group: Python 2.4
Status: Open
Resolution: None
Priority: 5
Submitted By: Matthew G. Knepley (knepley)
Assigned to: Nobody/Anonymous (nobody)
Summary: reload() is broken for C extension objects

Initial Comment:
1) A C extension module (foo.so) is imported

      import foo

2) The library foo.so is rebuilt with changes

3) We reload the module

      foo = reload(foo)

The reload() method calls imp.load_dynamic() which
eventually gets down to _PyImport_GetDynLoadFunc().
This just calls dlopen(), which returns the old filehandle.

This problem can be fixed by augmenting imp with
unload_dynamic(), which could easily be implemented in
a _PyImport_GetDynUnloadFunc(), which would just
consult its handles[] array, and call dlclose() on the
appropriate handle. This will work if Python was the
only program to dlopen() foo.so.

----------------------------------------------------------------------

>Comment By: Matthew G. Knepley (knepley)
Date: 2005-02-19 23:34

Message:
Logged In: YES 
user_id=58554

I have coded the proposed solution (changed import.c,
importdl.c, and dynload_shlib.c). I will assemble a test
case for it next week.

----------------------------------------------------------------------

Comment By: Matthew G. Knepley (knepley)
Date: 2005-02-19 16:37

Message:
Logged In: YES 
user_id=58554

I am only interested in fixing it for the dlopen() case,
which I thnk subsumes every architecture likely to have this
problem appear. I have no problem fixing it myself, but I
need to get all the CVS stuff setup. And I am not sure how
to easily generate the patch to send (I'm used to BK).

----------------------------------------------------------------------

Comment By: Michael Hudson (mwh)
Date: 2005-02-19 16:27

Message:
Logged In: YES 
user_id=6656

I don't believe this is quite as easy as you make out.  It might be 
possible to make something that works for platforms that use dlopen 
though...

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1144263&group_id=5470