[Matplotlib-devel] [Wheel-builders] Manylinux external library test case - matplotlib, tk

[Matthew Brett]

On Mon, May 23, 2016 at 12:53 PM, Matthew Brett <matthew.brett at gmail.com> wrote:
> On Tue, May 17, 2016 at 4:23 PM, Matthew Brett <matthew.brett at gmail.com> wrote:
>> Hi,
>>
>> On Wed, May 11, 2016 at 2:26 PM, Leonardo Rochael Almeida
>> <leorochael at gmail.com> wrote:
>>> On 11 May 2016 at 10:58, Matthew Brett <matthew.brett at gmail.com> wrote:
>>>>
>>>> On Tue, May 10, 2016 at 6:38 PM, Nathaniel Smith <njs at pobox.com> wrote:
>>>> > On Tue, May 10, 2016 at 3:09 PM, Leonardo Rochael Almeida
>>>> > <leorochael at gmail.com> wrote:
>>>> >> On 10 May 2016 at 18:52, Matthew Brett <matthew.brett at gmail.com> wrote:
>>>> >>>
>>>> >>> On Tue, May 10, 2016 at 5:26 PM, Matthew Brett
>>>> >>> <matthew.brett at gmail.com>
>>>> >>> wrote:
>>>> >>> >> [...]
>>>> >>> >>
>>>> >>> >> This would probably look like:
>>>> >>> >>
>>>> >>> >> _tkagg.so has a DT_NEEDED entry naming tkinter.so (or whatever
>>>> >>> >> Python
>>>> >>> >> calls
>>>> >>> >> this module)
>>>> >>> >>
>>>> >>> >> Before loading _tkagg.so, we use Python level introspection figure
>>>> >>> >> out
>>>> >>> >> where
>>>> >>> >> tkinter.so lives
>>>> >>> >>
>>>> >>> >> We add its directory to LD_LIBRARY_PATH
>>>> >>> >>
>>>> >>> >> we import _tkagg.so
>>>> >>> >>
>>>> >>> >> We take its directory back off of LD_LIBRARY_PATH
>>>> >>> >>
>>>> >>> >> Very weird, but I can't see why it wouldn't work, and probably more
>>>> >>> >> reliable
>>>> >>> >> than anything where we try to reimplement the dynamic loader's
>>>> >>> >> search
>>>> >>> >> logic
>>>> >>> >> ourselves.
>>>> >>> >
>>>> >>> > Nice - yes - it does work in a first-pass test - I'll look into
>>>> >>> > automating that.
>>>> >>>
>>>> >>> Ah - except I do not believe it is possible to change the linker path
>>>> >>> for Python modules, within the Python process:
>>>> >>>
>>>> >>> http://www.gossamer-threads.com/lists/python/python/393770#393770
>>>> >
>>>> > Doh :-(
>>>>
>>>> Any other suggestions?
>>>
>>>
>>> Calling `patchelf` at runtime with the result of introspecting the
>>> `_tkinter.so` module? :-)
>>>
>>> On a more serious note, even though it would be dangerous to call
>>> `sys.setdlopenflags()` with `RTLD_GLOBAL`, we could perhaps manually call:
>>>
>>> ctypes.CDLL("/path/to/introspected/libtk.so", DLFCN.RTLD_GLOBAL)
>>> ctypes.CDLL("/path/to/introspected/libtcl.so", DLFCN.RTLD_GLOBAL)
>>>
>>> before importing a `_tkagg.so` with `libtk` and `libtcl` patchelf-removed
>>> (but not re-added).
>>>
>>> We would be dumping only libtcl/tk's symbols in the namespace of other
>>> python extension modules.
>>
>> I have implemented dlopen dynamic loading of the TCL / Tk functions
>> from the Python tkinter extension module here :
>> https://github.com/matplotlib/matplotlib/pull/6442
>>
>> It appears to work.   I'd love any feedback y'all can offer.
>
> I patched matplotlib 1.5.1 with a version of the PR at [1]  to build
> the wheels using the script at [2] and travis-ci repo build at [3].
>
> The built wheels are up at
> http://ccdd0ebb5a931e58c7c5-aae005c4999d7244ac63632f8b80e089.r77.cf2.rackcdn.com/
> for testing.
>
> They work for me, for example doing tkagg animations.

Travis testing of these wheels, and some errors, reported at
https://github.com/matplotlib/matplotlib/issues/6469

Cheers,

Matthew