pid_t pidbuf[npids], *pids;
pid_t pidbuf[npids], *pids = pidbuf;
_hurd_priority_which_map (enum __priority_which which, int who,			  error_t (*function) (pid_t, struct procinfo *),			  int pi_flags){  mach_msg_type_number_t npids = 64, i;  pid_t pidbuf[npids], *pids;  error_t err;  struct procinfo *pip;  int pibuf[sizeof *pip + 5 * sizeof (pip->threadinfos[0])], *pi = pibuf;  mach_msg_type_number_t pisize = sizeof (pibuf) / sizeof (int);  switch (which)    {    case PRIO_PROCESS:      npids = 1;      pids[0] = who;      err = 0;      break;    case PRIO_PGRP:      err = __USEPORT (PROC, __proc_getpgrppids (port, who, &pids, &npids));      break;    case PRIO_USER:      err = __USEPORT (PROC, __proc_getallpids (port, &pids, &npids));      break;    default:      return EINVAL;    }  for (i = 0; !err && i < npids; ++i)    {      if (which == PRIO_USER)	{	  /* Get procinfo to check the owner.  */	  int *oldpi = pi;	  mach_msg_type_number_t oldpisize = pisize;	  char *tw = 0;	  size_t twsz = 0;	  if (err = __USEPORT (PROC, __proc_getprocinfo (port, pids[i],							 &pi_flags,							 &pi, &pisize,							 &tw, &twsz)))	    continue;	  if (twsz)	    /* Gratuitous.  */	    __vm_deallocate (__mach_task_self (), (vm_address_t) tw, twsz);	  if (pi != oldpi && oldpi != pibuf)	    /* Old buffer from last call was not reused; free it.  */	    __vm_deallocate (__mach_task_self (),			     (vm_address_t) oldpi, oldpisize * sizeof pi[0]);	  pip = (struct procinfo *) pi;	  if (pip->owner != (uid_t) who)	    continue;	}      else	pip = NULL;      err = (*function) (pids[i], pip);    }  if (pids != pidbuf)    __vm_deallocate (__mach_task_self (),		     (vm_address_t) pids, npids * sizeof pids[0]);  if (pi != pibuf)    __vm_deallocate (__mach_task_self (),		     (vm_address_t) pi, pisize * sizeof pi[0]);  return err;}