minix3/lib/libc/sys/priority.c

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2020-02-21 00:59:27 +05:30
/*
priority.c
*/
#include <sys/cdefs.h>
#include "namespace.h"
#include <errno.h>
#include <sys/types.h>
#include <sys/resource.h>
#include <lib.h>
#include <unistd.h>
#include <string.h>
#include <stddef.h>
int getpriority(int which, id_t who)
{
int v;
message m;
memset(&m, 0, sizeof(m));
m.m_lc_pm_priority.which = which;
m.m_lc_pm_priority.who = who;
/* GETPRIORITY returns negative for error.
* Otherwise, it returns the priority plus the minimum
* priority, to distiginuish from error. We have to
* correct for this. (The user program has to check errno
* to see if something really went wrong.)
*/
if((v = _syscall(PM_PROC_NR, PM_GETPRIORITY, &m)) < 0) {
return v;
}
return v + PRIO_MIN;
}
int setpriority(int which, id_t who, int prio)
{
message m;
memset(&m, 0, sizeof(m));
m.m_lc_pm_priority.which = which;
m.m_lc_pm_priority.who = who;
m.m_lc_pm_priority.prio = prio;
return _syscall(PM_PROC_NR, PM_SETPRIORITY, &m);
}