No rendering output when loaded from Python or Ruby: thread/signal problem

Hello,

I have libsylvain.so which has just one function hello_display() which displays an hello world windows through QT libraries.

I have this one program `sylvain' which is a single line program which calls sylvain_display from libsylvain.so.

When I run `./sylvain', I have some debug output from QT on the console, and the hello world window is displayed on my TV (I am running this on a Raspberry Pi with FreeBSD).

Now, when I run python2.7 or python3.6, and load libsylvain.so either through the ctypes module or through a C extension module, and call the sylvain_display() function from python or even ruby, I have the console log output from QT as with the `hello' program, but I don't have the window on my TV!

I guess the rendering to the TV is done on a separate thread and this one is not called or locked? What's strange is that all works from python when I use X11 backend instead of EGLFS_BRCM.

I came up with this simple test program to isolate the issue because both PyQT and PySide now don't work as expected, I have console log but no actual TV output with EGLFS_BRCM.

Hope you guys will figure this out.

libsylvain.cpp: http://dev.sylvaingarrigues.com/libsylvain.cpp
sylvain.cpp (test program for libsylvain): http://dev.sylvaingarrigues.com/sylvain.cpp
sylvain-ctypes.py (load libsylvain): http://dev.sylvaingarrigues.com/sylvain-ctypes.py

Also tried with a C extension to rule out ctypes bug, same issue:
sylvainmodule.cpp (python module wrapper): http://dev.sylvaingarrigues.com/sylvainmodule.cpp
sylvain-cext.py (load sylvainmodule and sylvain_display): http://dev.sylvaingarrigues.com/sylvain-cext.py

build script: http://dev.sylvaingarrigues.com/build.sh