Frank, I made my own code not using wiring pi, and the whole system hangs… not my program, the whole operating system is hanging when I poll the gpio device files in /sys/class/gpio. We are not talking about wiring Pi anymore, this is not about the readall function.
I create a separate thread which sleeps until changes are made to the file using linux poll() and linux select(). When it wakes, my other threads sleep, and the poll thread calls the ISR handler. This is the linux way.
The whole system hangs! If my app was the problem I should have my app hang, and the system still be accesible through ssh for example, or the command line. Not happening, everything hangs, and this has to be an issue with the gpio kernel module, there’s no other option here.