wait4
__strong_reference(__wait4, wait4);
while(wait4(-1, NULL, WNOHANG, NULL) > 0)
pid = ::wait4(savedpid, &pstat, 0, (struct rusage *)0);
while (wait4(-1, &childstatus, WNOHANG, NULL) > 0); /* wait for all dead children */
struct wait_args wait4;
pid_t wait4(pid_t, int *, int, struct rusage *);
r_pid = wait4(pid, &status, 0, &tr->rusage);
while (wait4(pid, &status, 0, &ru) != pid){
pid = wait4(-1, &status, 0, NULL);
pid = wait4(-1, &status, WNOHANG, NULL);
pid = wait4(cur->pid, &status, 0, NULL);
pid = wait4(cur->pid, &pstat, 0, (struct rusage *)0);
pid = wait4(-1, &status, WNOHANG, NULL);
pid = wait4(-1, &status, WNOHANG, NULL);