process descriptor facility
procdesc is a file-descriptor-oriented interface to
process signalling and control, which supplements historic
kill(2), and wait4(2) primitives with new
system calls such as pdfork(2), pdkill(2),
procdesc is designed
for use with capsicum(4), replacing process identifiers with
capability-oriented references. However, it can also be used independently of
capsicum(4), displacing PIDs, which may otherwise suffer
from race conditions. Given a process descriptor, it is possible to query its
conventional PID using pdgetpid(2).
procdesc first appeared in FreeBSD
9.0, and was developed at the University of Cambridge.