glibc/sysdeps/mach/hurd/getpriority.c

86 lines
2.8 KiB
C

/* Copyright (C) 1994-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <limits.h>
#include <hurd.h>
#include <hurd/resource.h>
/* Return the highest priority of any process specified by WHICH and WHO
(see <sys/resource.h>); if WHO is zero, the current process, process group,
or user (as specified by WHO) is used. A lower priority number means higher
priority. Priorities range from PRIO_MIN to PRIO_MAX. */
int
__getpriority (enum __priority_which which, id_t who)
{
error_t err, onerr;
int maxpri = INT_MIN;
struct procinfo *pip; /* Just for sizeof. */
int pibuf[sizeof *pip + 2 * sizeof (pip->threadinfos[0])], *pi = pibuf;
size_t pisize = sizeof pibuf / sizeof pibuf[0];
error_t getonepriority (pid_t pid, struct procinfo *pip)
{
if (pip)
onerr = 0;
else
{
int *oldpi = pi;
size_t oldpisize = pisize;
char *tw = 0;
size_t twsz = 0;
int flags = PI_FETCH_TASKINFO;
onerr = __USEPORT (PROC, __proc_getprocinfo (port, pid, &flags,
&pi, &pisize,
&tw, &twsz));
if (twsz)
__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;
}
#ifdef TASK_SCHED_TIMESHARE_INFO
if (!onerr && pip->timeshare_base_info.base_priority > maxpri)
maxpri = pip->timeshare_base_info.base_priority;
#else
if (!onerr && pip->taskinfo.base_priority > maxpri)
maxpri = pip->taskinfo.base_priority;
#endif
return 0;
}
onerr = 0;
err = _hurd_priority_which_map (which, who,
getonepriority, PI_FETCH_TASKINFO);
if (pi != pibuf)
__vm_deallocate (__mach_task_self (),
(vm_address_t) pi, pisize * sizeof pi[0]);
if (!err && maxpri == INT_MIN)
/* No error, but no pids found. */
err = onerr ?: ESRCH;
if (err)
return __hurd_fail (err);
return MACH_PRIORITY_TO_NICE (maxpri);
}
libc_hidden_def (__getpriority)
weak_alias (__getpriority, getpriority)