getsid
li->li_number = getsid(mypid);
if (getsid(0) != getpid())
pid_t getsid(pid_t);
int getsid(pid_t _pid);
if (pid != getsid(0)) {
s = getsid(0);
if (setsid() < 0 && (errno != EPERM || getsid(0) != 1))
pid_t my_sid = getsid(my_pid);
EXPECT_EQ(my_sid, getsid(my_pid));