# and register forked processes with &$register_worker(pid)
# Note: using $SIG{CHLD} = 'IGNORE' or $SIG{CHLD} = sub { wait (); } or ...
# has serious side effects, because perls built in system() and open()
# and register forked processes with &$register_worker(pid)
# Note: using $SIG{CHLD} = 'IGNORE' or $SIG{CHLD} = sub { wait (); } or ...
# has serious side effects, because perls built in system() and open()