Replace the existing code in QProcess that dealt with signaling of child
processes exiting with forkfd and spawnfd. The previous code was
convoluted and hard to maintain, having shown its age in the last
year. I've been running it for a year and a half and the new
implementation is definitely an improvement.
This change replaces support for the QNX Neutrino spawn() call with the
POSIX version. We lose the ability to do setsid(), but we gain quite a
few ioctls() that were done to fill in the file descriptor mapping
structure. That's also the only OS for which we have the ability to
thread-safely chdir() before the call to spawnfd().
Another advantage is that forkfd does not require a dedicated thread
running to handle child processes exiting.
Change-Id: I5eb76821dfdb6a8ed2989d7f53b3c31e515c3174
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>